Post on 14-Sep-2020
Jun-18
British Shorthair Breed Advisory Committee
Breeding
Policy For The British Shorthair
Guidelines
For
Healthy
And
Responsible
Breeding
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Summary
When an individual or group makes a decision to ‘breed’ an animal for any
purpose that decision carries a degree of responsibility. This British Shorthair ‘breed specific’ policy seeks to safeguard the genetic health, distinctive type and integrity of our wonderful breed, by providing
our breeders with sufficient information to inform their breeding programs or systems, such that they understand those responsibilities relative to
the genetics of the breed and seek to protect and improve all aspects of the most popular pedigree cat in the UK today.
This policy is intended to support and accompany the British Shorthair Registration Policy.
Acknowledgments
• The GCCF Breeding Policy
• Steve Crow and the Asian Breeding Policy
• Dr Diane D. Addie and her Invaluable Website.
• Contributing British Shorthair Breeders1
• Robinson’s Genetics for Cat Breeders and Veterinarians
• Photographers: Alan Robinson and Robert Fox
1 These can be found at Appendix 4 Contributing Breeders
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Contents Summary ...................................................................................... 2
Acknowledgments .................................................................. 2
Contents ....................................................................................... 3
1. Introduction ..................................................................... 6
1.1. Purpose of this Document........................................... 7
1.2. Exclusions .................................................................. 7
2. Background to the British Shorthair Cat ..................... 8
2.1. Origin .......................................................................... 8
2.2. Breed Description ....................................................... 8
2.3. The Show Cat ............................................................. 9
2.4. Registration ................................................................ 9
2.5. Characteristics and Temperament .............................. 9
2.6. Longevity .................................................................. 10
2.7. Recognition .............................................................. 10
3. Breeding System Information ..................................... 11
3.1. Genetic Make Up ...................................................... 11
3.2. Size and variety of gene pool .................................... 14
3.3. Inbreeding ................................................................ 15
3.3.1. Best Practice Advice and Recommendations ........ 20
4. Type ......................................................................... 21
4.1. Overall ...................................................................... 21
4.2. The Head .................................................................. 21
4.3. Nose ......................................................................... 21
4.4. Chin .......................................................................... 22
4.5. Ears .......................................................................... 22
4.6. Coat .......................................................................... 22
4.7. Eyes ......................................................................... 23
4.8. Body ......................................................................... 23
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4.9. Legs & Paws ............................................................ 23
4.10. Tail ........................................................................... 24
4.11. Size and Weight ....................................................... 24
5. Health ...................................................................... 25
5.1. Genetic Defects ........................................................ 25
5.1.1. PKD ...................................................................... 25
5.1.2. HCM ..................................................................... 25
5.2. Blood Groups and Neonatal Isoerythrolysis .............. 26
5.2.1. Recommendations ................................................ 28
5.3. Brachycephaly .......................................................... 29
5.4. Weight ...................................................................... 29
5.5. Infectious Disease .................................................... 30
6. The Self Coloured British Shorthair ...................... 31
6.1. The White Self .......................................................... 33
6.2. Black and Blue Self .................................................. 37
6.3. Chocolate or Lilac Self .............................................. 40
6.4. Cinnamon or Fawn Self ............................................ 42
6.5. Red or Cream Self .................................................... 45
6.6. Tortoiseshell (all colours) ............................................ 49
7. Non-Self/Non Tabby ..................................................... 52
7.1. Bi-colour ........................................................................ 52
7.2. Van Pattern (Preliminary) ............................................ 56
7.3. Tortie and White and Van Pattern Tortie and White . 59
8. Smoke ............................................................................ 61
9. Tabbies and Spotties ................................................... 64
9.1. Ticked Tabby ................................................................. 67
9.1.1. Ticked Tabby (All colours) Non Silver (Preliminary)67
9.1.2. Silver Ticked Tabby (Preliminary) .......................... 71
9.2. Mackerel and Classic Tabbies (non Silver) ............... 72
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9.2.1. Mackerel Tabby .................................................... 73
9.2.2. Classic Tabby. ...................................................... 75
9.2.3. Spotted Tabby (non-silver) .................................... 78
9.2.4. Silver Tabby, (All colours) ..................................... 79
9.2.5. British Silver Spotted Shorthair. ............................. 81
10. Tipped – Silver Series ............................................... 83
10.1. Black Tipped ............................................................. 83
10.2. Golden Tipped including all Non-silver Series Tipped.87
11. Colourpointed ........................................................... 92
11.1. Colourpointed, Non-silver, without white spotting ..... 92
11.2. Colourpointed -Silver Series ................................... 101
11.3. Colourpointed & White (Any colour) Preliminary ..... 104
11.4. Silver Colourpointed & White (Any colour) Preliminary106
12. British Shorthair Variant .......................................... 107
13. Eye Colour .............................................................. 109
14. Record Keeping ...................................................... 112
15. Recommendations .................................................. 114
Appendix 1 References .......................................................... 115
Appendix 2 Glossary .............................................................. 116
Appendix 3 Key Genes ........................................................... 117
Appendix 4 Contributing Breeders ....................................... 117
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1. Introduction
It is very easy to breed a cat, in fact if you share your life with a female cat and
do nothing to prevent it you will soon have a litter of kittens and a very good
mother taking care of everything. However, if one makes a decision to become a
breeder of pedigree cats all sorts of responsibilities accompany that decision.
Fortunately in the UK we have a well respected registration body, the GCCF2
which has an established framework that determines the Registration Policy for
each breed of cat and an official Standard of Points3. To accompany these, the
British Shorthair Group Committee (Breed Advisory Committee) 4 has compiled
this ‘breed specific’ Breeding Policy, the aims of which are to provide the
dedicated and ethical breeder with advice and guidance such that the cats that
they breed, whether for companion, show or breed purposes, are healthy, and
conform to the Breed Standard.
Breeding decisions become easier if breeders develop and manage a breeding
program within which they consider the key points of cat breeding, which are:
• Maintenance and perpetuation of the Breed
• Improvements in quality of the phenotype (appearance) as
measured against the Breed Standard
There is a trade off in any successful breeding program, in order to increase
homogeneity (similarity) we must reduce random variation. Therefore, breeders
must use a robust process of selective breeding.
2 Governing Council of the Cat Fancy 3 SOP 4 BAC
GCCF
BAC
Registration
Policy
Breeding
Policy
Breeders
SOP
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In doing so we run the risk that:
• Undesirable, and even harmful, genetic anomalies will begin to
express themselves
• extremes of physical type may begin to appear
• Inbreeding becomes attractive
In order to achieve the desirable goals, whilst managing the risks the breeders
system should give consideration to:
• The maintenance of a robust, healthy and viable breeding
population of cats.
• Properly documented monitoring of the outcomes of any
mating that produce anomalies.
• The wide range of genetic cat tests that are available.
1.1. Purpose of this Document
The purpose of this document is to provide breeders with some guidance as to
‘best practice’ in breeding the British Shorthair Cat and to ensure that the Breed
Standard, as set out within the Standard of Points, is at the forefront of any
breeding program, together with due regard for the health and integrity of the
breed.
1.2. Exclusions
This document is not intended to guide breeders as to the day to day welfare and
care of the breeding animal.
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2. Background to the British Shorthair Cat
2.1. Origin
The Romans introduced large numbers of cats to the United Kingdom as working
cats to help reduce the rodent population. These cats interbred with the native
wild cats of Great Britain to produce the native domestic shorthaired cat. The
accepted date of origin of the British Shorthair as we know it today is 1870.5
Despite being popular at the Crystal Palace cat show of 1871, by the end of World
War II along with many other British cat breeds, the British Shorthair numbers
were devastated. A number of careful breeders worked to recreate and restore
numbers using a combination of British Shorthairs, Persians, Russian Blues,
Burmese and other pedigree and non pedigree shorthair varieties.
Whilst the diversity helped with the health of the breed, breeders found that the
‘foreign type’ was persistent in the background and breeders found that they had
to keep falling back on the Persian occasionally to keep type. Always, the
objective was to reach a point where the British would breed true without any
need for outcrosses. (The longhair gene remains recessive amongst some British
Shorthairs today)6
2.2. Breed Description
The breed standard states that;
The British cat is compact, well balanced and powerful, showing good depth of
body, a full broad chest, short strong legs, rounded paws, tail thick at base with
rounded tip. The head is round with a good width between small ears, round
cheeks, firm chin, large round and well opened eyes and a broad short nose. The
coat is short and dense. A muscular cat with an alert appearance and in perfect
physical condition
Extract from the British Shorthair Cat Club;
The British Shorthair is one of the largest breeds of cat. It is chunky and
substantial; the male is much larger than the female. The face is round with full
cheeks and the nose is short and broad. The chin is deep and strong. The ears
are small and rounded and set so as to blend with the round contour of the head.
The eyes are large and round. The head is set on a short thick neck. The body is
cobby with a short level back. The chest is deep and the shoulders are strong.
The legs are short and strong with round paws. The tail is thick and of medium
length.
5 Robinson 6 Genetic tests for the LH gene are now available)
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Within these descriptions we can read that this is a cat whose beauty is all about
balance, size and roundness, balanced by strength and physical health.
2.3. The Show Cat
The British Shorthair is a hugely popular show cat and with the wide range of
colours and patterns available it is one of the biggest breed sections at GCCF cat
shows.
2.4. Registration
The British Shorthair is the most popular pedigree cat, with more kittens
registered with the GCCF each year than any other breed.
Registered breed numbers have risen by 48% over the past 10 years to almost
6,800 in 2008.7
2.5. Characteristics and Temperament
British Shorthairs are an easygoing breed of cat. They have a stable character
and take well to being kept as indoor-only cats, making them ideal for apartment
7 Latest GCCF data published
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living. They are not terribly demanding of attention, though they will let their
owner know if they feel like playing. They are not hyperactive preferring to sit
close to their owners rather than on them.
They like attention and enjoy being petted. They are not a very vocal breed but
will meow to communicate with their owners. British Shorthairs like to follow
people from room to room, as they often wish to be with their owner and see
what is going on. Some do not mind being cuddled, but most prefer to keep four
paws on the ground and be patted rather than picked up.8
2.6. Longevity
British Shorthairs are very healthy and long lived. You can expect a British to live
from 14 to 20 years.
2.7. Recognition
The British Shorthair is recognized by all the exhibiting bodies across the
continents.
8 Extract from Wikipedia
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3. Breeding System Information
As we can see from the background information the British Shorthair is a popular
and robust cat, deserving dedicated and ethical breeders with the time to
establish good breeding systems and practices. And whilst breeding cats is ‘just a
hobby’ it is not possible to breed responsibly without a basic understanding of
genetics.
We will cover some aspects of the genetics of our breed, but much more
information can be found in works such as Robinson’s Genetics for Cat Breeders
and Veterinarians and of course the Internet is a valuable source of materials for
those seeking further information.
For some experienced breeders much of this information is already well known
and understood, but as a BAC we have responsibility to help the novice breeder
establish a basic understanding.
One of the very first terms to get to grips
with is - Phenotype and genotype
The phenotype is basically, that which you can see, phenotypes result from an
individual’s genes as well as the impact of environmental factors and the possible
effect that the latter may have upon the former. The genotype is the genetic
make-up of a cell, or an individual.
That fabulous rusty coloured (phenotype) cat that you may admire as chocolate,
may well in fact be a very happy black (genotype) cat enjoying the sun
(environmental)
3.1. Genetic Make Up
Unlike many breeds where origins can be traced back to individual named cats,
the origins of the British lie very firmly with Felis Silvestris or Felis Lybica, a
mackerel tabby ancestor, with just a bit of help along the way.
By the beginning of the 20th century standards had been written for many of the
colours and type was generally as seen today, round compact cats with large
round heads and eyes, coats described as short and deep, fine texture with dense
undercoat.
(By 2009, the BAC determined that type had been successfully fixed and outcrosses no
longer permitted.)
In common with the Asian breed the BSH has one of the largest numbers of gene
variations of any breed of pedigree cat recognised by GCCF.
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Whilst we understand much about how these genes work, there are so many that
even the scientists struggle to understand and complex polygenes9 make the
effects of major genes even harder to get to grips with. Sometimes we have to
accept that the evidence for how these genes and polygenes work together lies in
the ability to breed with consistent results.
It will help if we explain that there are genes for colour and genes for pattern.
The genetic penny drops for many novice breeders when they are able to
separate the genes that govern colour from those that govern pattern
3.1.1.Coat Colours
Essentially there are four basic colours for coat or pigment in the cat, these are
Black, Chocolate, Cinnamon and Red.
Red is confusing because it isn’t really a colour in its
own right, it is actually a modifier of the other three
colours, but because the result is a distinct colour then it is
easier if we consider it as a colour
White is not a colour, it is a ‘masking’ gene that masks anything.
And just when it seems simple, we have to consider the effect of the dilute gene
on the basic gene colours. And it always helps breeders to understand the rules of
colour dominance.
Figure 1 shows the dominance hierarchy and the effect of the dilute gene.
Figure 1
9 Genes with small but cumulative effects on the expression of a characteristic
Dominant
Black
Dominant over Chocolate and
Cinnamon
Chocolate
Dominant over Cinnamon
Cinnamon
Dilute
Blue
Dominant over Lilac and Fawn
Lilac
Dominant over Fawn
Fawn
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Red is the sex-linked orange gene, ‘O’ and ‘O’ determines if there will be any red
or cream (dilute) hair. ‘O’ completely replaces the black pigment gene.
Because Red is replacing Black, Red is also a dominant colour. It is easiest if we
think of Red and Black as being of equal dominance.
3.1.2.Coat Patterns
It seems as we have more coat colours than we have because of the genes for
‘pattern’ which modify the colours. The main genes for pattern in the British are:
• The Tabby genes
• The Siamese gene
• Silver undercoat genes
• Bi-colour and white spotting genes
To help us get to grips with the genes for colour and pattern we need to know
some basic terms.
These terms will crop up throughout the document and so are well worth
understanding.11
Table 1- Basic Terms in Genetics
10 This list is repeated in the Glossary 11 A list of the key genes at work to produce the many patterns of British Shorthair can
be found at appendix 1.
Genes Are individual units of inheritance. Each gene (or combination of
genes) determines a characteristic that govern the eventual
shape, size, sex, colour, pattern and hair length of the individual
animal. Genes work in pairs – but the pairs do not have to be
identical
Chromosomes Genes are located on the chromosomes. All cats have 38
chromosomes in each body cell, 19 from each parent.
Chromosomes appear in pairs. With the exception of the sex
chromosomes each pair is the same size and shape.
Locus Is the exact position on the chromosome where the gene is
located
Allele Refers to the different forms of a gene
Homozygous Refers to having the same 2 alleles at a given locus on a
chromosome
Heterozygous Refers to having two different alleles at a given locus on a
chromosome
Dominant
Gene
Is one which is capable of expressing its trait even when carried
by only one member of a chromosome pair.
Recessive
Gene
can only express itself when both members of the chromosome
pair contain the gene10
Wildtype The phenotype of the most typical or normal form.
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3.2. Size and variety of gene pool
Any ‘best practice’ breeding system must include the planning of the actual
breeding program, this is where a breeder decides his or her objectives, seeking
to maintain good breed type, and make improvements. The breeder will make a
decision to mate a certain queen to a given stud, often with great hopes for the
outcome.
As a part of this policy document we will ask our breeders to consider health,
selection of parents and inbreeding.
In common with other pedigree breeds, we do not have an unlimited choice of
parent cats. Figure 2 shows an estimate13 of the number of British Shorthair
queens and studs contributing to the total number of kittens registered in 200915
Breed Kittens
Registered in
2009
Estimated
Queens
Estimated
Stud Cats
Self excluding
Red and Cream
2248 375 81
Silver Tabby Inc
Smoke
762 127 25
Colourpointed 438 72 15
Tortoiseshell16 405 68
Bi-Colour & Tortie
and White
322 54 11
Non Silver Tabby &
Red & Cream Self
302 50 17
Tipped (Silver & non
Silver)
204 34 7
Cinnamon & Fawn 29 5 1
White 23 4 1
Other 682 114 23
TOTALS 5,414 903 181
Figure 2 – Estimated Breeding Population
13 Assumptions: The average litter size is 4; the average queen will have 3 litters in 2
years. There is on average one stud cat for every 5 queens. 15 There is a table of British Registrations available on the BAC website 16 The calculated fathers of these tortie kittens have been shared between self and
red/cream.
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3.3. Inbreeding
Robinson’s Genetics’ section on inbreeding opens with
“Inbreeding is an emotional topic for some people”
Well it certainly is, the media are full of tales of ‘mutant cats and dogs’ and if one
‘Google’s’ ‘Inbreeding cats and dogs, the first four resources offered all refer to
‘problems’ However, as well as being ‘emotional’ it is also an extremely complex
topic. Therefore, in this section we will seek to provide basic information for
novice breeders and share some best practice advice from more experienced
breeders.
Further reading and information can be found both in Robinsons Genetics For Cat
Breeders and Veterinarians and also, the GCCF breeding policy17 provides a
section on inbreeding.
In line with our ethos of keeping this simple, it is virtually impossible for breeders
of the British Shorthair to avoid inbreeding. Data provided by Robinson18 tells us
that if we wished to prepare a 20 generation pedigree for two cats with no
duplicated ancestors we would need in excess of two million cats. To get this into
perspective we only have to see that the above table is suggesting that we have
somewhere in the region of 1000 queens and 200 studs currently at work in the
UK. We must also accept that of the possible 200 stud cats available, many of
these will be at closed stud, limited stud, or simply the wrong colour.
Within these constraints, breeders dedicated to producing healthy kittens will
always have to consider to what extent their chosen cats are related.
The following table provides an explanation of some of the terms used in
breeding.
Term Simple Explanation % Inbreeding coefficient
calculated19
Inbreeding This is the mating of closely related cats. Such as Father to Daughter, Mother to Son and Brother to Sister
25%
Line-
breeding
This term is not used by geneticists20, and is described as
a ‘less intense’ form of inbreeding.
But it is still breeding within a family line and may include Half Brother to sister, Aunt to Nephew,
Grandparent to Grandchild.
Single First Cousins
Single First Cousin to Second Cousin and Single Half First
12.5%
6.25%
3.13%
1.56%
17 Available free of charge on the GCCF website. 18 Robinson’s Genetics for Cat Breeders & Veterinarians. 19 Sourced from RGCB&V 20 To a geneticist it is all inbreeding.
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Cousin
Single Second Cousin
Some breeders would consider that mating cats that are related by at least one common ancestor within the first
three generations of their parents as line-breeding.
Outcrossing This is when the two parents are unrelated.
Realistically, in pedigree animals, this condition almost
impossible to meet. Especially within a ‘closed’ gene pool such as the British.
Breeders, often refer to an outcross when common
ancestor does not occur behind either queen or stud within a four /five generation pedigree. (i.e. when any
inter-relatedness cannot easily be seen)
Breed True Two parents with a desired phenotype produce
offspring of that same phenotype exclusively
Grading Up A rapid improvement of the quality of breeding
stock by mating inferior with superior strain.
Back Cross The mating a son or daughter to one of the
parents. Either to continue a ‘Grading Up’ process
or to capture a recessive gene
Inbreeding Depression
The loss of Hybrid Vigour.
Figure 3
So, we are saying that inbreeding is unavoidable, and to a certain extent we must
accept that despite the ‘bad press’ inbreeding is, if correctly managed, important.
After all without it we would not have the cat that we all know and love today.
The important point is ‘correct management’ and if we can ascertain some form
of best practice we can hope to influence the decisions of both experienced and
reputable breeders, who will hopefully mentor novice breeders and thus help to
keep a healthy balance of inbreeding within the breed as a whole.
In order to understand why breeders would wish to ‘inbreed’ we must go back to
our basic understanding of inheritance, the gene is the basic physical and
functional unit of heredity. Genes, which are made up of DNA, act as instructions
to make molecules called proteins.
Every cat has two copies of each gene, one inherited from each parent. Alleles
are forms of the same gene with small differences in their sequence of DNA
bases. These small differences contribute to each cat’s unique physical features.
When we mate two cats together their offspring will each be given one gene from
each parent, when these genes are different, the offspring will be said to be
‘heterozygous’ for the inherited characteristics.
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These genes will combine to determine (to a greater or lesser extent) the
following characteristics:
Therefore, it would seem to make sense that breeders will select superb
specimens of their breed to mate together and thus produce even more wonderful
cats. However, to produce cats which closely meet the desired standard, breeders
often mate together animals which are related and which share desirable physical
characteristics. Some breeders create a line which will ‘Breed True’ and breeders
can predict not just how the offspring will look, but that the offspring will, largely
be uniform within a litter.
All of this sounds fine so far until we remember that it is not only the ‘phenotype’
of the cat that is ‘breeding true’, behind the scenes the ‘genotype’ may also
becoming uniform.
This is caused by a switch in the genetic makeup from a heterozygous state, to
one which is ‘homozygous’
Once again, if the breeder is responsibly managing all four aspects of the above
inherited characteristics, and can be reasonably certain that all the kittens from
these ‘inbred’ matings will be sound, healthy, long-lived and able to produce,
without difficulty, sound and healthy kittens. Then all will be well.
Health
Temperament
Reproductive Ability
Coat Colour & Type
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Where it starts to go potentially wrong is when any one or any group of breeders
start to breed for certain characteristics such as ‘coat’, – breeding a daughter
back to her father in the hope that:
Is fine unless both cats also carry the gene for disease, then sadly the
outcome for the offspring could be very bleak.21
It is not just the risk of genetic disease that comes with inbreeding. The more
that we use inbreeding to ‘fix’ desirable traits the more likely it is that kittens will
also inherit the same set of genes for the immune system from both parents, and
be born with potentially compromised immune systems. Persistent inbreeding will
build up over successive generations as the offspring become genetically more
uniform, an increase in sickness may result.
The GCCF recommend that breeders calculate the inbreeding coefficient – If we
look at Figure 3, we will see that we can add a ‘percentage’ value to the offspring
of any mating we do. The calculation works on a ‘path’
21 Please note that this diagram is illustrative. The genes for PKD and HCM are both
dominant mutations. Therefore, cats only need to carry one copy in order to develop
disease. However, it is thought that kittens born with two copies of the HCM mutation are
more likely to develop serious disease and PKD is almost certainly a deadly double domiant.
Short Crisp Coat
Short Crisp Coat
Short Crisp Coat
PKD/HCM PKD/HCM PKD/HCM
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The following ‘traffic light’ might be useful for breeders able to calculate the
coefficient.22
% Coefficient
Figure 4
The truth is that there are no hard and fast rules that can help us determine a
‘safe level’ of inbreeding. What we can do, both as individuals and as a group is
to ‘listen’ to our cats. There is no perfect coefficient ‘number’ that can declare one
mating safe and another risky – one sure fire way of knowing that we are going
too far is too look out for signs of Inbreeding Depression, some of which are23:
• Males showing signs of reduced ‘sex drive’ or fertility
• Females failing to come into heat or failing to conceive
• Falls in average litter size
• Low birth weight
• An increase in stillbirths
• High kitten mortality
• An increase in abnormal kittens
• Kittens failing to thrive or grow into healthy good sized adults
• Signs of poor immune systems leading to an increase in infectious
diseases.
Of course, any of the above signs may occur randomly, or indeed may be
traceable to a single animal, which could then be removed from a breeding
program. True inbreeding depression, describes an ongoing state of affairs that
will continue unless responsible breeders step in and make a genetic correction.
22 Taken from GCCF Breeding Policy 23 Taken from various sources including Robinson
1-25%
• ACCEPTABLE• Over 8 Generations (where only 5 generations 1-17%
26-39%
• BE CAREFUL• Over 8 Generations (where only 5 generations 17-27%)
40-50%
• STOP• Over 8 generations (Where only 5 generations 28-33)
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There is a risk that all of this sounds very depressing, but in truth many
experienced breeders naturally manage their breeding programs holistically,
taking all the characteristics into consideration. These, our best breeders, will not
hesitate to remove an otherwise superb physical specimen from their breeding
programs if a genetic defect is suspected or found.
The following advice might help inform a
‘good breeding program’
3.3.1.Best Practice Advice and Recommendations
• Breeders should avoid inbreeding as much as possible.
• Stud cat owners should ask for copies of the pedigree of any queen
wishing to be mated.
• Novice breeders should always take advice from a mentor.
• Breeders should only use inbreeding as a part of their breeding system
when they are certain that they have the ability and experience to
recognize early signs of inbreeding depression. (and the courage to make
any necessary corrections)
• Kittens from closely related parents should not be sold to novice breeders.
• Remember breeders computer programs can only feedback on data input
– if only 4-5 generations are available for a breeding coefficient calculation
– the program cannot calculate the inbreeding of any missing generations.
• Ensure that you understand the pedigree of any cat you might wish to buy
for breeding or use at stud, avoid kittens with pedigrees where any one
ancestor is over represented.
• Avoid over use of ‘fashionable’ stud cats
• Breeders may work in groups and agree to avoid any inbreeding within say
three or four generations of a pedigree.
• Importing new bloodlines will refresh the gene pool. However, check the
pedigree to ensure that the overseas breeder is not breeding from recently
purchased UK stock.
• Breeders to accept collective responsibility for the breed health and
integrity.
The good news is that the BSH does not show signs of dangerous inbreeding at a breed level.
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4. Type
This section is intended to add additional information to inform breeders as to the
phenotype24 we should all be aiming for.
4.1. Overall
The British Shorthair cat is compact, well balanced
and powerful, showing good depth of body, a full
broad chest, with generous, strong shoulders standing
four square on short thick legs, with strong hips. He
has rounded paws, with a tail thick at the base with a
rounded tip. A muscular cat with an alert appearance
and in perfect physical condition.
We are looking for a cat that has an overall body
shape that is a series of curved or rounded shapes
from his head and paws to the tip of his tail.
4.2. The Head
The Breed Standard looks for, a round face with full cheeks and good breadth of
skull with round underlying bone structure. The head should be set on a short
thick neck. A good way to describe a ‘good head’ is a broad apple shape with
chubby cheeks.
Importantly, the head should always be in balance with the body, an oversized
head is just as undesirable as a head that is too narrow.
The eyes are large, round and should be an important facial feature. Top breeders
aim for a sweetness of expression as well as eye colour.
4.3. Nose
The Breed Standard calls for a nose that is short,
broad and straight. In profile, a rounded forehead
should lead to a short straight nose with a nose
break that is neither too pronounced nor too
shallow.
Almost all experienced breeders of the British
Shorthair will know that ‘short, broad and straight’
seems so simple and yet the reality is that getting
the British Shorthair nose and forehead right is
frustratingly difficult.
24 The ‘visible’ cat
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Keeping the nose short, with a balanced break is just one of the juggling acts
most breeders have to perform.
Irrespective of fashion the extreme Brachycephalic look is not a feature of
the British Shorthair25.
4.4. Chin
The Breed Standard is very clear, a strong, firm and deep
chin is essential.
Any deviation from this to be considered a fault.
The bite MUST be level, the tip of the chin to line up with
the tip of the nose in the same vertical plane.
Breeders seeking to emphasize the roundness to the head
seek to create a slightly rounded chin and powerful jaw.
4.5. Ears
Breed Standard asks for, small, rounded at the
tips. Set far apart, fitting into (without distorting)
the rounded contour of the head.
External ear to be well covered with fur, internal
furnishings not to be excessive.
Getting those ears right presents a real challenge
to our breeders, why oh why do ears want to be
large and sitting high on the head?
Experienced breeders remove the ear tufts for
showing to accentuate the roundness and
neatness.
4.6. Coat
The SOP26 calls for a coat that is short, dense and crisp. A soft and / or overlong
and fluffy coat is incorrect.
The above statement makes it all sound so simple, yet the British Shorthair coat
is unique, no other cat breed has this wonderful coat. Read through Judge’s
reports and find words such as cracking, crisp, scrunchy, dense and firm. Judges
25 Shortened muzzle and face 26 Standard of Points
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also refer to coats as being, too soft, too long, lying flat and lacking in density. So
how do we know when we have that coat right? Judges will press the coat feeling
for a firmness and density of undercoat, when held between two fingers the coat
should not stand higher than the fingers by very much. If the coat is stroked
backwards towards the head, a ‘good’ coat will remain standing erect.
4.7. Eyes
Breed Standard says,
large, round and well-
opened.
Set wide apart with no
tendency to Oriental
shape. No squint.
For some breeders it is all in the eyes – not just colour - but shape and set.
4.8. Body
The SOP says - Cobby type with
short level back.
Low on legs with broad deep chest.
Equally massive across the shoulders
and the rump.
Medium to large, but not rangy.
We are looking for cat with hips and
shoulders of the same width.
A well balanced cat will also have a firm body, without sagging. Breeders are
looking for good bone and a sound muscular body.
4.9. Legs & Paws
The Standard asks for; Short strong legs.
Paws round and firm. Toes carried close, five on each
forefoot (including dew-claw) and four on each back
foot.
That gentle roundness carries right through even to
the feet.
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4.10. Tail
According to the SOP the tail should be thick and of medium length, thicker at the
base with rounded tip.
4.11. Size and Weight
The male British is noticeably larger, broader and rounder than the female, with
weights ranging between 6-7 kilos. But the female is also a big cat with weight,
when in condition, around 5-6 kilo’s.
The British is a slow growing cat and should be given time to mature. The adult
will not reach full maturity until three to four years of age.
The British Shorthair may be a big cat but it should not be a fat cat.
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5. Health
5.1. Genetic Defects
Just as genes determine all the good characteristics they also contribute to many
‘bad’ characteristics. We only have to look over our shoulder at some of the
unfortunate attributes that have slipped into some of the pedigree dog breeds.
But closer to home, the Munchkin Cat has been produced as a result of deliberate
breeding of a genetic mutation. Genes also contribute to disease and as breeders
seek to fix type they may inadvertently fix disease.
Fortunately, there are tests available for some devastating genetic diseases and
breeders can make informed choices. Reputable breeders should be aware of the
genes that can adversely affect the British. Where testing is possible, these
should be performed routinely and affected animals removed from breeding
programs.
Section 6 of the GCCF Breeding Policy gives details of the well known genetic
anomalies; we will just mention two of these:
5.1.1.PKD
Polycystic Kidney Disease – PKD, a gene mutation which causes enlarged
kidneys composed of dilated cystic channels, resulting in early kidney failure and
death. This mutation has been found in the British Shorthair. Fortunately simple,
effective DNA tests are available. These can be undertaken by your veterinary
practice or simple swab tests can be carried out at various laboratories27
5.1.2.HCM
Hypertrophic cardiomyopathy (HCM). Sadly, according to the Feline Advisory
Bureau a familial incidence of HCM has been reported in the British Shorthair
breed. Whilst this may be due to an inherited gene defect, as yet the defective
gene has not been identified in this breed. (See screening scheme info on
www.fabcats.org/hcm)
The GCCF section on genetic anomalies states that the majority of HCM is
genetic. Unfortunately, at the moment testing in the British is limited to scanning
with ultrasound, which can be unpleasant for the animal and expensive. Amongst
British Breeders in Europe, annual HCM tests have become routine, but it has not
yet become custom and practice for British Breeders here in the UK. Our current
recommendation is that any breeder with reason to suspect an inherited HCM
condition in any of their cats, should seek a scan and if the animal is affected
remove him or her from the breeding population. Any progeny should also be
scanned and monitored.
27 A list of laboratories can be found on the BAC website – some of these offer discounts to breeders as members of the breed clubs
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5.2. Blood Groups and Neonatal Isoerythrolysis
Blood Group Mismatch is an issue for the British section. As a BAC we have
decided to include a section on Neonatal Isoerythrolysis as it is the kittens of our
breed that are most likely to be affected by blood group mismatch.
It is estimated that 92 % of the UK domestic shorthair feline population are blood
group A. However, only 47% of the British Shorthair population are group A, the
remainder being blood group B or the very rare AB. In recent years blood group
‘mismatch’ has been identified as being responsible for some cases of fading
kitten syndrome.28
There are experienced breeders in the UK today who have bred cats for many
years who do not know the blood group of their cats, who add new stock to their
lines and yet have never lost a kitten due to blood group mismatch. There are
others who have sad stories of entire litters have lost to a fading kitten syndrome
that has been diagnosed as Neonatal Isoerythrolysis.
Fortunately today it is possible for breeders to test their breeding cats for blood
type in their own homes using non-invasive inexpensive swab tests.29
The following detail is extracted from data provided by UC Davis.
The A and B blood groups are genetically determined.
UC Davis has proposed the following ‘naming’ system:
Nomenclature Blood
Group
Genetic Make Up Note
A A A/A, A/a or A/b Dominant to B
a AB Probably less than 1% of
all cats.
b B b/b
A genetic mutation associated with the B blood group in most cats has been
identified and a DNA test has been developed. Animals can be tested at an early
age from a buccal swab.
The DNA blood group test identifies cats that have the B serotype (two copies of
b allele) and also that are B carriers (one copy of the b allele, A or AB serotypes).
Because the DNA test cannot distinguish between a Type A versus a Type "AB"
cat, the non-b allele is reported as "N". The cat could have a Type A or Type AB
serotype.
28 Data courtesy of Dr Diane Addie and FabCats 29 DNA Laboratories can be found online via search engines. Many cat clubs operate a
discount scheme with accredited laboratories.
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Results reported as:
Test
Result Blood group status
N/N Cat is Type A or Type "AB"
N/b Cat is a carrier of B factor; serotype could be Type A or Type
"AB"
b/b Cat is Type B
Once a breeder knows the blood type of all their breeding cats they need to
understand that Neonatal Isoerythrolysis represents the most serious problem to
any A offspring of a B mother. This risk increases with every mating that may
result in A group kittens. The effect of the antibodies is accumulative.
On her website Dr Diane Addie makes the following statement regarding Ab
Queens mated to Ab studs and thus potentially carrying B group kittens -
“Queens with blood group A have less anti-type B, antibody than blood group B
queens have anti-group A, antibody, so the type B kittens of this mating might
survive. However, if the mating is repeated, the queen will build up anti-B
antibody and eventually one fourth of her kittens could die of Neonatal
Isoerythrolysis.”
Despite much research amongst UK BSH breeders we have no evidence that
kittens from Ab to Ab matings are fading from NI. However, record keeping is
vital and if breeders experience any fading kitten in Ab to Ab matings blood tests
may help to inform future matings.
Figure 5 shows how to calculate any risk (note we have ignored AB as it is so rare
and is covered by Dr Diane Addie in full)
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Figure 5 shows that a B group stud can be mated to any queen and an A queen
can be mated to any stud. Breeders need to manage the matings and or kittening
of their B group queens. Records of any fading kittens in Ab to Ab matings should
be kept.
5.2.1. Recommendations
1. Breeders should use available technology to inform their breeding
programs. (ie, Blood Group Tests)
2. Inexperienced Breeders with B group queens should seek to mate those
queens to B group studs.
3. Kits to test blood group using placental blood are available.30
30 These are available to Veterinary practices from the Oxford Cat Clinic.
Ab, or B Stud
Ab Queen
Offspring will be either blood group A, Ab or B Risk Increases
For B group kittens
A, or Ab Stud B
Quee
Offspring will be either blood group Ab or B
Any non B kittens may be at risk
B Stud B
or A Queen
Offspring will be either blood group B or Ab Not at Risk
It is the antibodies from B group dams that represent the greatest risk to A kittens
Figure 5
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5.3. Brachycephaly
Brachycephalic is a word that is hard to say, meaning short headed or broad
headed, wherein the length of the cranium is shorter than the width. This gives
the top and sides of the cranium a round shape, often referred to as 'apple-
head'.31 Whilst we are very happy to have that lovely apple-head description, if
one were to Google ‘Brachycephalic’ all sorts of distressing articles and images
appear, especially in relation to poor breeding practice in the dog world.
As the British BAC, our remit is
limited to the welfare of the British
Shorthair, and whilst we are
attracted to a short, broad nose we
are also very proud of the
reputation that the British
Shorthair has for health and for
being as natural as possible for a
pedigree cat.
5.4. Weight
The British can be a lazy cat, and may be prone to weight gain. Overweight stud
cats can find the mating act difficult. Overweight queens may have difficulty in
getting pregnant and giving birth.
Keeping your breeding ‘team’ at
the right weight takes patience
and skill, but the health benefits
to your cat are worthwhile
31 Wikipedia
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5.5. Infectious Disease
There is much information available for breeders regarding infectious diseases
both viral and bacterial. The feline, unlike the canine, is not a pack animal, and
there is no doubt that the feline physiology cannot cope with the stress that can
accompany some cattery environments.
We recommend that breeders acquaint themselves with the following diseases,
such that they understand symptoms, treatments, impact and remedy.
Table 2
Viral Bacterial Parasites
Feline Calicivirus (FCV) Feline Chlamydia Fleas
Feline Panleukopenia (Distemper)
Campylobacter Ear Mites
Feline Leukemia Virus (FeLV)
Bordetella Bronchiseptica Hookworms,
Ringworms and Tapeworms
Feline Rhinotracheitis (Feline Herpesvirus)
Toxoplasma Coccidia
Feline Immunodeficiency Virus
Streptococcus Tri Trichomonas
Corona (FCoV) and Feline Infectious
Peritonitis
Staphylococcus Giardia
Ringworm
Key: Diseases in Green have vaccines available. Blue, have treatments available.
Red, these diseases have no vaccines or treatments in common use.
Our best recommendation is that all our breeders find a good Vet, one that is
prepared to be a partner on our journey to produce happy healthy British
Shorthairs. Breeding is teamwork and the support and care of a good Vet is
invaluable.
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6. The Self Coloured British Shorthair
In order to understand the genes for coat pattern at play in the British self we
must first understand the Agouti (A) gene - the natural “wild” gene that is the
basis of the tabby cat. The base agouti pattern is bands of black on a yellow or
orange background. This dominant, wild-type (A) causes the agouti shift
phenomenon which causes the hairs to be black pigmented at the tips and orange
pigmented at the roots this is overlaid with one of the tabby patterns.
There are three tabby patterning genes, which give rise to the patterns that we
know: Mackerel (Mc) with the basic stripes, Classic (mc) a mutation of (Mc)
which blotches the pattern, Ticked (T), a form that removes most of the stripe
pattern, Spotted (Sp) a gene that breaks the pattern into spots.
Working with the tabby patterning genes we have the Wide-banding (Wb) gene.
This little understood, and much argued over, gene has the effect of pushing the
darker, pattern colour in the cat up away from the hair base towards the tip,
turning the normal tabby patterns into a Shaded or Tipped cat.
Now that we understand the basis for the ‘original’ pattern of the BSH ancestor,
we must now accept that genes can mutate32 overtime.
When the dominant Agouti gene (A) mutated into the weaker Non-Agouti gene
(a)33 what actually happened was that the gene became faulty and no longer
works properly, so that the little genetic trick known as the ‘agouti shift’34 simply
doesn’t happen, or at least not properly in (aa) cats.
In the absence of the ‘agouti shift’ the basic tabby cat turns into a self black
because the whole hair shaft is allowed to fill with eumelanin35 meaning that the
whole animal appears black, although often in certain light the underlying tabby
pattern may still just be discernible, especially in kittens. Other genes work to
change this black pigment to other colours.
Something important for breeders of the self coloured British to bear in mind is
that whilst not all cats are Agouti, they are all Tabbies, the loss of the Dominant A
gene does not affect the base tabby pattern. Thus those underlying patterns we
see in kittens can be stripes, spots or indeed ticked.
Another point to note at this early stage is that the (A) to (a) mutation has little
effect on the (O) allele36 This explains why it is almost always possible to see the
tabby markings on red and cream non agouti cats.
Our beautiful British Self coats are created in the embryo. Very early on, all the
particles responsible for the colour of the coat flow into the hair shafts. This is a
very complex process, not just technically, but also impacted by genes and
polygenes that are not yet fully understood. What seems to be important to the
‘self’ is the speed of this process, the faster the colour pigments pour into the
shaft the more even the hair colour becomes.
32 Mutations are changes in the DNA sequence of a cell's genome 33 Also known as the Hypermelanistic gene 34 Far too complicated for this section 35 Black pigment 36 The gene responsible for Red and Cream
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In the British Self we are looking for a coat with hairs that do not fade out as they
get closer to the skin. This can be helped by selective breeding of individuals that
have the most solid coats. What we are probably playing with are those
polygenes that control the depositing of the melanin in the hair shaft and the
length of time that the process takes.
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6.1. The White Self
Introduction
A beautiful cat with a
sparkling non-silver white
coat and dramatic eye
colour, the white self is not
often seen on the show
bench today, although
when one does appear it
generates a lot of interest.
In the early days of the
British Shorthair they were
very popular working cats
often found in Flour Mills!
It is estimated that the White Self represents less than half a percent of total
kitten registrations.
With a legacy of hearing problems and a need to understand the dominance of
the genes for white coats the white self cat is a breed for the experienced and
ethical breeder.
It will help at the outset if we understand that White is not a colour in the sense
that Black is a colour – we need to think of a white cat as one that has not got a
colour and thus appears white.
Genes for Coat
The gene (W) that causes a cat to have a white coat is a dominant masking
gene37. A white cat can be a homozygous white (Ww. 2 white genes) or
heterozygous (Ww. one white gene/one nonwhite gene).
Keeping this very simple, what happens is, that as the embryo forms, the W gene
interrupts some of the normal cellular activity, and those cells, for pigment or
colour, that multiply and spread over the embryo, effectively get stopped in their
tracks, so the skin of the newborn kitten has no pigment and the kitten is white.
A completely white cat could carry the genes for red/black, agouti/non-agouti,
dilute/non-dilute, etc, but despite any hidden genetic codes for coat colour and
pattern the cat may have, the cat will always be visually white.
Pure white cats often have a small patch of colour on the head at birth. This spot
is evidence that the process of distributing cells for melanin actually started, but
was then halted by the W gene. This is why this spot may reveal what colour the
kitten carries. These patches usually disappear as the cat matures.
37 Epistatic
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It is, in rare cases possible to have a cat with
a naturally white coat without this gene, as an
extreme form of white spotting38, some small
non-white patch usually remains, if only during
kitten-hood.
This sweet baby aged 11 days carries the
mark she was born with. The pigment mark
shows how the pigment started to ‘migrate’
before the W gene caused the process to stop.
Eyes
Breeders are seeking to achieve the following eye colours:
• Deep Sapphire Blue
• Orange, preferably copper, deep orange or deep gold
• Odd eyed, one each of the above two striking colours
As the white coat may be masking many coat colours or patterns including the
Himalayan gene40 the source of the eye colour in the white cat may not always be
known. A blue eye colour, for example, may be as a result of have de-
pigmentation of the iris of one or both eyes, or may be as a result of the
Himalayan gene.
Nose and Paw Leather
Bright Clean Pink for the British White
The Show Cat
Breeders are looking for a white ‘self’ which should have a dense pure white coat
un-tinged with yellow. Kittens may have slight blue/black markings on their
heads which should disappear when they reach maturity.
Specific Health – Skin Care
Due to the lack of pigmentation in the skin, white cats are more sensitive to
sunlight and are more likely to affected by sunburn and develop skin cancer.
Deafness
It would be irresponsible not to mention the deafness that is associated with the
gene for White (W).
38 See White Spotting Gene and Section on Bi-Colour British 40 See Appendix 1 and Section on Colourpointed.
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There is much data available giving statistics, the following data paints a picture.
• Deafness in the general cat population is extremely rare
• 5% of the general cat population is White
• Estimates are that about 50% of these cats are deaf in one or both ears
and when one or two eyes are blue the chances of deafness rises to nearer
80%
During our research for this section we came across several papers each arguing
the case both for and against the existence of a gene for deafness in white cats.
In the absence of a definitive position we must settle for the generally accepted
position which is;
• There may be a gene for deafness which may be found one day.
• The deafness may be caused by the W gene halting the normal migration
of pigment cells that causes both the eye to be blue and the degeneration
of the canal of Corti, (the part of the cochlear duct that leads to deafness)
• Studies have shown that it is the same stem cells that cause the lack of
pigment in the blue eye and the absence of a cell layer in the inner ear
that is found in deaf cats.
• White cats irrespective of eye colour may be deaf, but it is more common
in blue-eyed white cats than in yellow-eyed.
• The deafness is caused by the W, gene working with polygenes.
• Odd-eyed cats are often deaf on the ear which is situated on the same
side as the blue eye.
What all this tells us is, that we breeders need to be very careful when dealing
with the W gene, and studies have proved that there is a considerable fall in the
incidence of deafness in pure bred cats, so it is clearly possible to breed a healthy
hearing White cat.
Best Practice and Responsible Breeding
• GCCF registration of white male stud cats requires a BAER test.
• The registration policy for the White self restricts full registration to
matings between White and Self/tortie.
• Responsible breeders, of white cats will breed only from cats that have
undergone the BAER test which tests for bilateral hearing.
• Caring and ethical breeders can promote awareness of the test on their
websites to raise the profile of the test in cats and hopefully steer people
away from breeders that may not have the interests of the unborn kitten
at heart.
• Breeders should offer copies of their BAER test certificates to people
buying their kittens.
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Recommendations White Self
• All White British Shorthairs on the active register irrespective of gender
should be BAER tested.
• White x White breeding should be discouraged (research suggests that
cats that carry two copies of the W gene (WW = homozygous) are more
likely to produce deaf offspring.
• As any cat can be covered by the white gene, Breeders should mate cats
as close to the breed standard as possible to produce whites that are as
good as they can be.
• Breeders looking to achieve a higher incidence of odd eyed whites in their
breeding programs might like to consider experimenting with Bi-colours
with UNEAVEN facial markings41
41 One breeder interviewed suggested that using cats with perfect V shaped blazes
seemed to produce a higher number of kittens with single eye colour.
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6.2. Black and Blue Self
Introduction
The British Blue almost needs no introduction
being the most loved of all pedigree cats in the
UK today.
Together with the Chocolate and Lilac series, the
British Black and Blue account for almost 42% of
all BSH registrations42
Genes for Coat
Colour Agouti Black Dilute Orange White
Black aa B- D- oY/oo ww
Blue aa B- dd oY/oo ww
B- = BB or Bb or Bbl
To arrive at the coat that defines the superb cat that is the British Black we must
go back to the Non-agouti (a) gene the recessive gene mutation that turns the
basic tabby cat into a self black. The pigment granules in each hair of the cat's
coat contain Eumelanin43 which is black. Black melanin or eumelanin granules are
thought to be oval in shape and absorb almost all light.
The B (black/brown) gene has a
lightening effect on eumelanin. The D
(dense/dilute) gene affects the density
of pigment in the hair and affects the
eumelanin, the effect is a washed out
version of the original colour and the
Jet Black of the British Black becomes
the light to medium blue that is so
desirable.
Black is a dominant gene for
colour
The above genetic explanation of colour does not explain the superb texture of
the British Black and Blue coat. The plush, dense coat sets the standard for all the
other British Breeds’.
42 Data provided by the GCCF using 2009 registration data 43 Eumelanin is, in the absence of colour modifier genes, black
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The blue colour of a British Shorthair can range from a gentle pale grey to a dark
charcoal. The colour should be solid and even throughout the body. Any ghost
tabby rings on the tail are forgiven only in immature cats.
Eyes
Breeders seek to achieve dramatic effects with stunning eye colour of copper,
orange or deep gold. Eyes should be large and round, giving rise to a sweet, open
expression.
Nose and Paw Leather
Nose leather follows coat colour. Black for the Black British and Blue for the Blue.
The Show Cat
The sight of the British Black at the top of his or her game on the show bench
always causes a stir and high awards are usually met with great approval, the
black needs to be jet black, with no paling to the roots, the coat must be dense
and plush. Eye colour needs to be as good as it can be. This fabulous coat will
show any dust so good grooming is vital. Kittens may show some rustiness, but
this will not be expected in the adult cat.
The British Blue carries the
banner for the breed and
competition is very tough.
Breeders work very hard
to achieve the balance of
coat; texture and colour,
eyes; shape and colour,
ears; size and set; body;
size and weight and
because this is such a
popular colour, judges all
know just how good this
cat can be. The SOP calls
for a light to medium blue
coat in the show cat and
heavy silver tipping is a
fault.
There should be no tabby markings in either cat on the adult show bench.
Best Practice, Responsible Breeding and Recommendations
• Breeders seeking to breed from black or cats with other genetically
dominant traits should ensure that they understand how the genes for
colour and dilution are inherited. Breeding from a black cat that does not
carry the genes for dilute or chocolate/cinnamon will only produce black
cats.
• Just because the British Blue enjoys huge popularity both on and off the
show bench – breeders should not compromise on type or quality.
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Silver Tipping
One of the topics of discussion during review of this breeding policy and the
seminar held in April 2011 was the Silver Tipping seen on the coats of some
British Blues.
Despite some detailed research we have as yet been unable to determine the
genetic nature of the ‘tipping’ seen on some blue coats or to ascertain as to when
the British Blue coat first started to show this tipping.
If we go back to our introduction we can read that after both wars many other
breeds of cats known to have this Silver Tipping were used to re-establish the
British.
There is much debate amongst established breeders as to whether what we see
today is a relatively new phenomenon or something that has ‘always’ been there.
There are some renowned Blue breeders who are actively breeding to keep their
lines free of this tipping, whereas others feel that it is a not unattractive price to
pay for an otherwise good for type cat with a pale blue coat.
As genetic information becomes more available we will, hopefully, learn more
about the genetic make-up of our most popular colour of British. In the
meanwhile breeders are free to choose the polygenic phenotype of their breeding
programs, whilst our Judges have to make their own interpretation of the
definition ‘heavy silver tipping’
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6.3. Chocolate or Lilac Self
Introduction
The chocolate British Shorthair is a huge favourite and very desirable companion
animal. The chocolate colour mutation was first seen in the Siamese breeds,
where it was thought to be ‘just a poor or strange’ Seal44 Records for the
Chocolate Siamese appear in the 1880’s and they were first registered by the
GCCF in 1950.
It was not until the 1980’s that breeders started to bring the colourpointed
pattern into the British Shorthair and with it the Chocolate and Lilac colours.
The Chocolate Self did not gain championship status at GCCF shows until 2009.
Genes for Coat
Colour Agouti Black Dilute Orange White
Chocolate aa bb or bbl D- oY/oo ww Lilac aa bb or bbl dd oY/oo ww
The chocolate colour is a true mutation of the gene for Black and can be found by
gene tests. In chocolate cats, the round or oval black pigment granules
(eumelanin) which absorb almost all of the light, are a bit flattened. This means
more light can be reflected and the coat looks paler. This gene for Chocolate is
recessive.
When we add two copies of the dilute gene to
the Chocolate cat the result is a delicious lilac
shade.
Nose and Paw Leather
Nose leather and paw pads should be a Pinkish lilac.
44 Seal is the colour description for the Black Colourpointed
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The Show Cat
The breed standard for Chocolate calls for any shade of rich chocolate in a sound
coat with chocolate or pink nose leather and paw pads.
The Lilac cat should be a Frosty grey with a distinctive pinkish tone, giving an
overall lilac appearance.
The Chocolate and Lilac series are always popular on the show-bench. Judges are
looking for chocolate coats that are the mid-warm tone of a chocolate Labrador,
which are also sound to the roots, something that breeders find hard to achieve.
Best Practice, Responsible Breeding and Recommendations
• Experienced breeders of the chocolate colour find that using black self cats
within their breeding programs helps to produce chocolate or lilac coats
with more desirable tones to the colour.
• Novice breeders should appreciate that this colour is relatively new to the
breed and still needs work to get sound coats.
• Rufous genes appear to be reducing barring and making colours warmer in
other breeds. Selective breeding should help to see whether this can also
be true in chocolates and lilacs.
• Some breeders advise breeding chocolate cats not carrying the
colourpointed gene
• Some trial matings are showing that chocolate coats in cats carrying
cinnamon are lighter in shade.
• Experienced breeders are experimenting with the effect of using cats
known to have an underlying non agouti ticked base pattern to see if there
is an improvement in the quality of the coats.
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6.4. Cinnamon or Fawn Self
Cinnamon is the third true cat colour. Just as the Chocolate ‘b’ gene is flatter and
longer than the oval shaped Black ‘B’ the Cinnamon (b¹) granules are even longer
and thinner than those in the Chocolate, causing the hairs to be a lighter and
warmer brown colour.
The dilute gene causes the Cinnamon colour to fade to Fawn. Fawn is similar in
tone to lilac but is paler, perhaps more beige in colour.
Genes for Coat
Colour Agouti Black Dilute Orange White
Cinnamon aa b¹ b¹ D- oY/oo ww Fawn aa b¹ b¹ dd oY/oo ww
Although we are attempting to keep the genetic explanations as simple as we
can, the truth is feline genetics are complex, and the genes that we do
understand and can test for work in complex ways with genes that we cannot test
for and can only really ‘prove’ by experiment and testing our theories.
And whilst the above table shows that the Cinnamon gene for colour looks an
awful lot like the black gene for colour on paper, the truth is that little b¹ gene
has travelled a long way into the British and has potentially bought some
interesting companions.
In order to explain, we need to go back into the history, firstly of the Cinnamon
colour, and secondly how it has arrived onto the British show bench today.
History of the Cinnamon colour45
Essentially the Cinnamon colour was first identified in the Sorrel Abyssinian. This
cat had been labeled as ‘red’ until the late 1960’s when tests proved that the
genotype of the Red Abyssinian was in fact that of a Cinnamon Tabby. The genes
responsible for the Abyssinian coat pattern are dominant to most other genes,
hiding recessives such as non-agouti, other colours and other tabby patterns.
Cinnamon arrives in the British Section
It was a passion for the richness of the Cinnamon colour that tempted a group of
breeders to seek to introduce the colour into the British early in the 1990’s. Much
discussion over ‘where to go’ to outcross ensued, with the Abyssinian and the
Oriental being the main contenders. Eventually it was decided to go out to the
Oriental46.
45 Interesting reading includes - The Abyssinian Cat, by Vicky Hakin Smith 46 Malsome British Shorthairs have some background information.
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The main reason for choosing the Oriental over the Abyssinian was the fact that
the Abyssinian ‘genotype’ included the dominant ticked agouti gene and the
Oriental Cinnamon Self is a non agouti cat.
The Oriental section had originally out-crossed to the Abyssinian47 but selective
breeding of the recessive ‘a’ gene produced a cat with all the magnificent colour
of the Abyssinian in a non ticked form.48
Those of you still paying attention will note that, although the agouti gene may
have bowed out leaving his recessive cousin in charge – the underlying non-
agouti tabby pattern passed through the subsequent generations may well be
‘ticked’49
The first outcrosses started, and what a task these
brave breeders set themselves – the Oriental50 is a
beautiful cat, but the phenotype is almost as far from
the British as it is possible to get.
It takes passion and a great deal of patience and
many many years to convince all those polygenes to
make the shift from the Oriental to the British and we
should be proud of those dedicated breeders who
break the first ground
Nose and Paw Leather
Nose leather and paw pads should be a pink or
cinnamon brown.
A lovely example of the Fawn Coat.
Now, does that coat look as if it has an
underlying non-agouti ticked base?
47 More information can be found via the ‘The Oriental Cinnamon and Fawn Breeders Group’ 48 Just out of interest see both cats at shows – note the effect the ticked agouti gene has on the colour. 49 The effect the underlying (non-agouti) pattern may have on the British Coat is a ‘hot topic’ in the
British section. 50 Photo of Mewzishun Symphonia taken by Alan Richardson in 1996. This cat shows the Oriental
Cinnamon type as used by the British/Cinnamon project.
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The Show Cat (Preliminary Status)
The breed standard for Cinnamon calls for a warm cinnamon brown and for Fawn
a warm rosy mushroom.
This wonderful, short legged,
cobby girl with
neat ears shows just how much
has been achieved by some of our
ground breaking breeders.
Best Practice, Responsible Breeding and Recommendations
• Novice breeders should appreciate that this colour is relatively new to the
breed and should seek to understand fully the pedigree of any breeding
animal.
• Getting ‘type’ right is imperative. This cat’s ancestor has, large tall ears
and a long nose – selection will be key as this breed progresses.
• Experienced breeders are removing the colourpointed gene from the
phenotype of some lines – to ‘fix’ the Cinnamon and Fawn Self.
• As this breed moves into Championship Status, it is likely to be adopted by
a greater number of breeders. Remember, to protect the colour, that
warm burnt sienna, cinnamon colour, was after all what the last 20 years
was all about.
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6.5. Red or Cream Self
Those budding geneticists amongst us, will have remembered that the (A) to (a)
(agouti to non-agouti) mutation has little effect on the (O) allele51 This explains
why it is almost always possible to see the tabby markings on red and cream non
agouti cats. So it is not surprising that breeders are still working hard to get the
Red Self through the Preliminary Status52 stage. Whereas the dilute form, the
British Cream is a very popular cat both on and off the show-bench.
Because the genetics of the red and cream series start to get a bit more
complicated it is not surprising that when they popped up in Tortoiseshell litters in
the 1800’s breeders were often uncertain how to actually breed the cream self.
It was not until the 1920’s that breeding programs became established.
Having explained eumelanin53 we now need to get to grips with the only other
feline pigment – phaeomelanin the pigment for red. Essentially what the ‘O’ gene
does is get rid of any eumelanistic 54pigment from the hair shaft.
We must also remember that in the dominance stakes black and red are equal.
And whilst we practice pronouncing ‘phaeomelanin’ we must also take a step back
to our biology lessons and recall the rules that determine whether we are male or
female or more importantly whether our cats are male or female.
Each cat has two chromosomes for ‘SEX’ or gender –
Females, have a pair of chromosomes that appear identical and are X shaped.
Therefore, we refer to females as:
XX
Males also have a pair of chromosomes, but one of the males chromosomes is
smaller and looks like a Y or an incomplete X with the right lower ‘leg’ missing.
XY
The reason this is important information is because the genes for colour55 are
carried on the X chromosome and once the penny drops that girls have two XX
places to carry or inherit colour/pigment and boys only have one X to carry or
inherit colour/pigment we can begin to understand why we can have tortie’ girls
but not boys. The ‘O’ gene sits on the X chromosome and we call it a ‘sex
linked’ gene
51 The gene responsible for Red and Cream 52 Preliminary status breeds compete in Assessment classes 53 The pigment for black 54 Black, Chocolate, Cinnamon 55 Important to note this refers to the genes for colour – NOT the genes for pattern.
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The following table may help:
Example XY Genotype Phenotype
XX Black on both X
Chromosomes
Black Female
XX One black & one Red X Chromosome
Dominant Tortie Female
XY Black on X
Chromosome
Black Male
XY Red X Chromosome Red Male
XX Red on both X
chromosomes
Red Female
Figure 6
• If any cat carries two copies of the dilute gene then cats will be blue,
cream or dilute tortie.
• We can substitute chocolate or cinnamon for black in Figure 6and the rules
still apply.
For those of you still with us, we will just do a quick reminder of how gender is
inherited and how that affects this ‘O’ gene.
In order to be a boy the male cat has to have one copy of the Y chromosome,
which he can only get from his father. This is balanced by an X from his mother.
Therefore, an orange/red male always gets his gene for colour from his mother.
A female cat gets an X from each of her parents.
Genes for Coat
Colour Agouti Black Full
Coat
Dilute Orange White
Red aa C- D- OY/OO ww Cream aa C- dd OY/OO ww
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This picture shows a delicious cream female
at the top of her game.
The delicate cream
tones that make this girl blend into her blankets
are exactly what breeders are trying to
achieve. However, it is
not easy to produce this pale, balanced,
colouration.
The good news is that Breeders are making progress and this colour group -
together with the non-silver series of tabby – is one of the few British Shorthair
varieties that had an increase in registrations in 2009.
Nose and Paw Leather
Leather should be brick red for the red and pink for the cream.
The Show Cat
The cream colour should be an even-toned cream, with as few markings as
possible and no white hairs. Paler shades are preferred. Kittens are forgiven any
ghost tabby markings.
Best Practice, Responsible Breeding and Recommendations
• A popular mating to produce good examples of the cream is blue-cream
females mated to blue or cream males.
• It is thought that producing cream kittens from a red or dominant tortie
parent carrying dilute may contribute to a ‘hot’ cream. However, some
breeders have found the reverse to be true!
• Because the Red-Self is still at the preliminary stages, breeders are still
working ‘against’ the genes that make the agouti markings appear on non-
agouti cats. Some of the breeding ‘trials’ underway include:
• Working with ‘Rufousing polygenes’ 56which seem to blur the contrast
between the pattern and the ground colour.
• Breeding self cats with an underlying base pattern that is ticked tabby
rather than classic, spotted or mackerel57
56 Appendix 3 57
Ticked Tabby (footnote continued)
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A beautiful youngster
showing an underlying non agouti spotty
pattern
A lovely rich red girl
– so rarely seen
Ticked Tabby (All colours) Non Silver (Preliminary
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6.6. Tortoiseshell (all colours)
This is a very popular variety of the British Shorthair, especially amongst
breeders who find the multi-colour useful in breeding programs and who also
appreciate just how difficult it is to produce a ‘correctly’ patterned ‘tortie’ for the
show-bench
Just when things were starting to get simple, we learn that the tortoiseshell
pattern is not genetically a pattern – it is actually something that happens when a
cat is born with two colours showing.
A female cat inherits an X chromosome from each of her parents.
If neither parent has the gene for ‘red’ then the colour of the female kitten will be
determined according to the rules for colour inheritance58
If the father is red or cream,59 then his daughter can only receive that colour
from him and so she will have one X chromosome with the red colour carried. If
her mother is also red or cream she will have two X X and she will be a red or
cream female. If the dam is Black, Blue, Chocolate, Lilac, Cinnamon or Fawn,
then we will have a tortie female.
What happens next is complicated,60 but important to all tortie breeders.
Shortly after the mating, the original cells start dividing like mad. Quite quickly, the process
determines that there is altogether too much ‘stuff’ coming from both those XX’s – and so the
process shuts down or inactivates one of the X chromosomes in each cell.
This shutdown is random and happens early in the embryo. But meanwhile some
of the cells for colour from each of the two XX’s have ‘made it through’ we can
see this visibly in skin cells as they produce either red or black61 pigment and as
the skin cells multiply they form patches of varying sizes and shapes. It is
thought that the red and black cells multiply equally and actually compete with
each other. It is the resulting ‘mosaic’ of colour that determines the distribution of
red and black.
What this means is, that to all intents and purposes, the arrival in a litter of a
beautifully marked tortie is largely due to good fortune.
Genes for Coat
Tortie Colour
Agouti Black Full Coat
Dilute Orange White
Dominant aa B-/bb-/bb¹ C- D- Oo ww
Dilute aa B-/bb-/bb¹ C- dd Oo ww
58 Robinson’s genetics have a table showing the likelihood of colour
inheritance (thankfully) 59 Note: These rules also apply to bi-colours, colourpointed or tabbies with
red. 60 And not completely understood as yet 61 Or one of the black/blue mutations.
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A Black/Red (dominant
tortie) kitten, showing
beautifully
mingled colour distribution.
Despite the
‘naughty tortie’
reputation, this delightful cat
has the 4th highest
registration
numbers.
Nose and Paw Leather
Pink and/or the colour corresponding with the coat colour.
The Show Cat
The tortoiseshell is a mixture of the base colour with red or cream as appropriate,
evenly intermingled, with both colours clearly defined over the whole animal but
without any obvious patches of any colour. A small blaze on the face is
permissible.
Judges will fault, uneven balance of colour, unbroken legs and paws, tabby
markings and brindling.
The tortie is shown in the following combinations: Black, Chocolate and Cinnamon
with Red and Blue, Lilac and Fawn with Cream.
Best Practice, Responsible Breeding and Recommendations
• The tortie is also what is called an obligate heterozygote. Therefore, she
cannot breed true. And as we have learned that the distribution of colour
is largely out of the breeders hands, we should seek to breed our torties’
using the best for health, temperament and type parents that we possibly
can. In doing so even if we fail to achieve that oh so desirable mingled
coat we will at least produce kittens that are otherwise correct for eye
colour, coat etc, that will be happy, healthy kittens that are a credit to our
breeding.
• Breeding from an otherwise ‘poor’ tortie with good mingling will probably
just end in disappointment.
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• Experienced Breeders might like to experiment with the Rufous
polygenes,62 to see if they can see an improvement in the richness of the
tortie reds.
Just for the record we will settle the argument as to whether this section is really ‘one for the girls’ or not. According to Robinson’s Genetics one in every 3,000 male cats born is a
‘tortie’. Those of you with enough time to invest in understanding the reasons for something so rare will find the answers in Robinson’s under the section ORANGE.
62 These have not yet been identified, but breeders are enjoying selecting for them nevertheless
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7. Non-Self/Non Tabby
7.1. Bi-colour
The Bi-Colour represents the 5th most popular of British Shorthairs registered,
making up almost 6% of the total registered.
A well bred Bi-Colour is an extraordinarily pretty cat causing much admiration.
They can be shown in any of the recognized ‘self’ colours with the addition of
white.
Those of you who think that the sentence above suggests that all we have do is
mate the self white with any of the self colours and hey presto! we will get Bi-
colours just haven’t been paying attention. The gene for White is W, which always
delivers a completely white cat.
The gene responsible for our beautiful Bi-Colour is known as the ‘S’ gene.
The S gene, known as the Spotting gene or the Piebald gene is a Semi-dominant
Gene63 and produces variable results. A cat may have almost no visible white
spots or may be completely white, with almost any variation in between.
In the British it is the S gene that is needed to produce both the Bi-Colour and
Van Pattern64. The S/s gene is extremely variable, the following diagram65 may
help.
63 Producing an intermediate phenotype in the heterozygous condition 64
Van Pattern (Preliminary) 65 Thanks to Wikipedia
Figure 7
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In Figure 7 we could guess that:
• Cats with high to medium grade spotting (numbered 7-9) would be
homozygous for the S gene, (SS)
• Cats with low to medium grade spotting (numbered 2 – 4) would be
heterozygous for the S gene (Ss)
• Cats with medium grade spotting (numbered 5-6) could be either SS or
Ss.
The British Bi-colour cat falls very neatly into the mid-point and although we
cannot yet test for this gene we can be fairly certain that our Bi-colours may fall
into either genetic ‘camp’
This
wonderful
picture just
may help
with all the
genetic
information
in this
section.
Unlike the tortie, the British breeder is able to influence the Bi-colour through
selective breeding. This is because by breeding only the cats with a lot of white
on them you can increase your chances of getting cats with more white. This is
possible because every gene that we know about has all those little polygenes
hanging around, it is these polygenes that help to influence the amount of white
inherited and it is widely accepted that selective breeding can make good use of
polygenes.
At this stage it is worth a shortened and simplified explanation of the geneticist’s
best guess as to how the white pattern is ‘formed’
After mating, and the egg is fertilized, cells change66 and multiply, and begin to
form what will be the ‘finished’ kitten. During this embryonic stage some cells
called melanoblasts start to move, or migrate from the top (neural crest) of what
will be the kitten, down towards the bottom of the embryo.
66 Differentiation
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These cells, become the cells that produce melanic pigment (colour).
If these cells do not contain either the white gene (W)67 or the spotting gene (S)
they will cover the whole embryo and the result will be a fully coloured kitten.
If the cells contain one or two copies of the spotting gene, (SS or Ss) a defect
occurs and the migration of cells fails to complete and the parts of the kitten
furthest from the neural crest does not get a fair share of ‘colour cells’ and the
result is white patches – this is why so many breeders refer to the white pattern
as ‘falling to the bottom’ when in fact it is actually the colour that fails to fall!!!
Genes for Coat
Bi- Colour Agouti Black Full Coat
Dilute Orange
Spotting
Dominant B aa
B-/bb-/bb¹ C- D- Oo Ss
Dilute B aa B-/bb-/bb¹ C- dd Oo Ss Dominant O
aa
C- D- OY/OO Ss
Dilute O aa
C- dd OY/OO Ss
Eyes
Colour in line with the breed standard for the Self British. Incorrect rim colour or
flecks will be faulted.
Nose and Paw Leather
Pink and/or the colour corresponding with the patches.
The Show Cat
Judges are looking for patches of one self-colour
and white. The patches must be clear and well
defined, without tabby markings. At least one
third and not more than half the coat to be
white. No scattered white hairs. The coloured
patches must be sound and any blue must not
have silver tipping.
Symmetry of design is desirable, with colour on
the top of the head, the ears, cheeks, back, tail
and flanks. Tail to be fully coloured.
67 It seems that the W gene also interferes with melanic migration – almost as soon as it starts
around the neural crest – it is thought that this melanic ‘defect’ is related to the deafness that is
associated with the W gene.
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Exploding Some Popular Bi-Colour Myths (Just for Fun)
• The Bi-Colour gene does not have anything to do with the White Masking
gene (W)
• Mating your Bi-Colour to a white cat will not add any more white to your
Bi-colour program68 • Using Bi-Coloured cats in a breeding program does not cause lockets
Best Practice, Responsible Breeding and Recommendations
• It is clear from the high expectations from the Breed Standard that the Bi-
Colour is not a cat for the novice breeder. Getting the pattern and self
colour right for the show bench calls for hard work and dedication. As we
have read, the show quality coat can be selectively bred, and using a dam
or sire with poor markings can set back a breeding program.
• Working with Bi-Colours teaches breeders a huge amount about just how
diverse cat genes can be – those at the top of their game, must have
patience in abundance and a sense of humour.
68 Geneticists are confident that the W gene sits at a separate locus from the S gene. Experienced
Breeders (anecdotally) report using White (W-) cats with Bi colour (S-) does result in high grade Bi-
colour – see section on Van Pattern.
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7.2. Van Pattern (Preliminary)
The Van Patterned British Shorthair is a rarely seen attractive cat, that can be
bred in all the British self colours with white. The phenotype is a white cat with
colour confined to the head and tail, although up to three small patches of colour
on the body are acceptable.
Essentially the Van
Pattern British is an
high grade Bi-Colour,
and if we go back to Figure 7 we can see
that the Van Pattern
is a grade 8 or 9
suggesting that the
genotype for the Van
pattern is usually the
dominant piebald or
spotting gene SS.
It is generally accepted that selective breeding can exert influence over the tricky
Spotting gene and his polygenic mates69, which is why Breeders of the Van
Pattern British have sought to get this (probably) dominant variety recognised in
its own right.
Because both the British White (W) is an established breed, as is the Bi-Colour (SS or Ss) it seems sensible to expand upon the genetics of the Van at this point
as (at least, in phenotype) the Van seems to fall part way between the two
genotypes.
Some breeders of both White and Bi-Colour have long assumed that the Spotting
gene is just a different form70 of the White gene. This is understandable because
in practice the two genes work in such a similar way.
Much work has been done to prove that there are in fact two separate genes in
two separate places71 The following figure seeks demonstrate evidence for there
being two separate genes in two places.
69 Birman Breeders have done wonders with Gloving! 70 An allele 71 Loci
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Time for a little lesson in the inheritance of genes!
Figure 8
Figure 9
In Figure 9 we mate a non agouti, heterozygous Self White male (1) masking
black to a non-agouti, homozygous blue Van Patterned female (2) and we get a
Self White Kitten (3)
If we look at kitten (3) we can see that he has inherited his W gene from his dad
and his w gene from his mother. Because it sits at different locus from the W
gene he gets an S gene from his mother and the s from his father. He gets the B,
black gene from both his parents so he is genetically black. He gets the dilute
gene from his mother. When he grows up and we mate him to cat (4) they have
a blue self kitten, who gets her father’s w gene paired with her mother’s w gene,
she gets an s, a B and a d from each of them and so we get a non-agouti, non
white, non spotted, dilute black cat, in phenotype and genotype a Blue Self.
1
Self White Sire
aa Ww ss B-D-
2
Van-Patterned Dam
aa ww SS B-dd
3
Self White Male Kitten
aa Ww Ss B-Dd
3
Self White Male Kitten
aa Ww Ss B-Dd
4
Blue Self Female
aa ww ss B-dd
5
Blue Self female Kitten
aa ww ss B-dd
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Genes for Coat
Colour Agouti Black Full Coat
Dilute Orange Spotting
Dominant aa B-/bb-/bb¹ C- D- oY /oo Ss or SS Dilute aa B-/bb-/bb¹ C- dd oY/oo Ss or SS Dominant O
aa
C- D- OY/OO Ss or SS
Dilute O aa
C- dd OY/OO Ss or SS
Eyes
The breed standard calls for eye colour to be
deep gold or copper or orange. (there is
anecdotal evidence of deafness in blue eyed
van patterned cats, this breed standard is a
wise example of selective breeding)
Nose and Paw Leather
Pink or corresponding body colour
The Show Cat
The breed standard is looking for a cat with one self colour with white. He patches
should be clear and well defined with no tabby markings. A predominantly white
cat with small patches of colour on the head, but not below the level of the eye or
beyond the base of the rear of the ears. The colour on the head should preferably
be separated by a vertical white blaze. The tail should be fully coloured. For
perfection, no colour on the body or legs but up to three small thumb prints of
colour on the body would not fault an otherwise superb show cat.
Best Practice, Responsible Breeding and Recommendations
• Until the Van Pattern is established and can breed true, and we can be
certain that that high white gene for Van (probably homozygous for
spotting SS) does not start to bring a hearing problem into the Bi-Colour,
it is recommended that only experienced breeders, with experience of both
White Self and Bi-Colour breeding, undertake a Van breeding program.
• If novice breeders wish to join a breeding program they should be
mentored.
• Breeders should keep detailed records of all matings and outcomes, both
positive and negative. Keeping good records of ALL kittens born to a
breeding program are valuable aid in informing decisions.
• Breeders finding evidence of best practice that would suggest a review of
the registration policy should gather evidence and approach their breed
club.72
72 Anecdotal evidence suggests that mating a self white to tri-colour produces ‘good Van’s.
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7.3. Tortie and White and Van Pattern Tortie and White
The Tortie and White is another very popular cat on the show bench causing
heads to turn. The tortie and white can be bred in any of the usual tortie colours.
Called the Tri-colour, by breeders, genetically, the tortie and white is ‘just what it
says on the box’ but our old friend the white spotting gene SS or Ss has an
interesting effect on the tortie pattern.
Remember the ‘migration’ that the cells for pigment make73, with the red and
black competing for space – resulting in a mingled cat? And then add the ‘lazy’
factor that the white spotting gene SS or Ss brings74, causing the migrating cells
for colour to stop, before they reach the bottom of the cat?
It seems that the spotting gene causes fewer pigment producing cells. Therefore,
less competition between them as they migrate into position. Cells reach an area
and then multiply where they are to create a patch of colour.
Genes for Coat
Tortie Colour
Agouti Black Full Coat
Dilute Orange Spotting
Dominant aa B-/bb-
/bb¹ C- D- Oo SS or Ss
Dilute aa B-/bb-
/bb¹ C- dd Oo SS or Ss
73 See Tortie Section 74 See Bi-Colour Section
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The Show Cat
A good show girl will have patches of
base self-colour, with either red or
cream and white. The patches must be
clear, well defined and balanced without
mingling or tabby markings. For the
non-Van patterned at least one third,
and not more than half the coat to be
white, with patches of colour on top of
the head, ears, cheeks, back, tail, legs
and flanks. Tail to be fully coloured.
(Van patterns to have markings as per Van pattern.
Symmetry of design is desirable, with colour on the top of the head, the ears,
cheeks, back, tail and flanks.
Nose and Paw Leather
Pink or corresponding body colour
Best Practice and Recommendations.
• Although we have seen in the ‘Tortie’ section that Breeders cannot
influence that tortie mingling, it seems that the ‘S’ gene can be ‘biddable’
so have some fun and just see if the bigger the white areas, the bigger
and better defined the separate patches of blue and cream become.
Oh! – And don’t forget that type matters!!
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8. Smoke
Rarely seen on the British Show-bench, the Smoke is a ‘self’ non-agouti (aa) cat
with the addition of the Dominant Melanin Inhibitor (I) gene and whilst we may
not often see a fine example of the British Smoke, the impact of the Inhibitor
gene is all around us and it would be wise if we get to grips with it sooner rather
than later.
Some Facts
• The I gene is called the Inhibitor gene because it ‘inhibits’ the feeding of
melanin or colour into the growing hair75. • It seems to have more effect on the part of the hair shaft with the least
pigment, which is the part of the hair nearest the body.
• The gene seems to have a stronger effect on the production of the
pigment phaeomelanin76 more than the pigment eumelanin77. • It has a ‘variable’ effect in aa cats (that do not have the agouti gene)
What this results in is a self coloured cat with a silver undercoat and breeders are
looking for a cat with as much contrast as possible between a good strong self
colour and a shimmering clear silver/white undercoat.
The problem is that the Silver78 (I) gene is extremely unpredictable in the
absence of the agouti (A) gene and breeders rarely get what they would like.
The problems are many and varied, the inhibitor gene may actually not inhibit
very much at all and then the little bit it does inhibit might not be a glorious silver
white colour and instead may be a murky dark grey colour that blends into the
‘self’ coloured hair shaft. To add insult to injury, the (I) gene may also cause the
‘self’ colour to be washed out or rusty. These Cats with little contrast between
under coat and
top coat
colours may
look self
coloured. And
if that isn’t
enough, the
smoke cat
would love to
be a tabby and
ghost markings
abound. At this
75 Not like the S gene that affects melanin getting to skin cells
76 Orange 77 Black 78 Inhibitor
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point we can blame all the various, nameless, polygenes yet to be identified, but
the fact remains, breeding a good smoke is tough going.
This is possibly a sensible place to ‘discuss’ the registration policy regarding cats
with ‘Silver’ in the pedigree. To experienced breeders of cats incorporating the
Silver gene, it can often be irritating to receive GCCF paperwork over-stamped
with ‘Silver in Pedigree’. And yes, as a BAC we understand that the difference
between a good Brown Spotty and a Black Silver Spotty is very evident even to
novices. But it quite simply isn’t that simple. In the wrong hands, a poor smoke
may well be bred as a self. The over stamping of Silver is intended to be
informative. To those who know what they are doing, it should be of no
consequence whether the beautiful British Blue they are breeding from has an
ancestor who was a Silver, nor should it matter if the registration paperwork
makes reference to that ancestry. Colourpointed Breeders are grateful for this
information, as it can be extremely difficult for even the most experienced
breeder to discern the Silver, especially in the Tabby colourpointed series.
Genes for Coat
The Smoke may be bred in any of the self or tortie colours.
Eyes
Large and round, should be copper, orange or deep gold in colour.
Nose Leather and Paw Pads
Corresponding with coat colour and mingled with pink for torties.
The Show Cat
The top coat should be one of the recognised self or tortie colours, over a silver
undercoat. When the cat is still it will look solid-colored, but when the coat is
parted the silver should flicker through creating an ephemeral effect.
Recommendations and Best Practice
Smoke Agouti Black
Full Coat Dilute Inhibitor Orange
Dominant B
aa B-/bb-/bb¹ C- D- I
oY/oo
Dilute B aa B-/bb-/bb¹
C- dd I oY/oo
Dominant O
aa C- D- I OY/OO
Dilute O aa C- dd I OY/OO
Dom/Tortie
aa B-/bb-/bb¹
C- D- I Oo
Dilute/Tortie
aa B-/bb-/bb¹
C- dd I Oo
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• The British Smoke can be a lovely sight on the show bench. Often
produced as a ‘by-product’ of a silver program, this cat can be overlooked.
Any show quality variety needs work.
• There are some superb examples of the Smoke cat to be found on the
Persian show benches, with breeders devoting entire breeding programs to
this variety. Never forget, we all have much to learn from experienced cat
breeders, irrespective of breed.
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9. Tabbies and Spotties
In the section on The British Self, we said that in order to understand the genes
for the ‘Self’, we must first understand the Agouti (A)79 gene. We then went on to
deliver a couple of paragraphs about ‘agouti’ and ‘tabby’, throwing in the odd
‘Mc’s’ for good measure. In doing so we made it all sound oh! so simple. For
those of you wanting an easy life turn back now; because, despite our best
efforts, it’s going to get a teensy bit complicated now.
Part of the problem is that we live in very exciting times for the discovery of
genetics and our understanding is being constantly challenged and as breeders
we are necessarily in the business of experimentation and boundary pushing. Far
better then, that we are as informed as much as possible about the ‘genotype’
that makes up our beautiful cats.
Hopefully, by now, we know that a self cat is non agouti (aa) but rather
confusingly a self cat is still a ‘tabby’, this is because all cats are tabbies. And this
is one of those ‘light bulb’ moments for most cat breeders, when the
understanding dawns, that there are TWO genes that make a cat a TRUE TABBY
as we know it.
So all cats have the ‘T’ gene for pattern, but only tabbies have the A gene for
Agouti. It is almost as if the A gene turns on a magic switch that lets us see the
pattern. Before we go any further, it would be sensible to agree on the symbols
we shall use for this section.
The Agouti gene (A) is nice and easy, but the (T) (tabby) gene is not quite so
simple and often causes confusion. This is because of the relationship between
the Ticked, Classic/Mackerel and Spotted Tabby genes. Recent studies80 have
suggested that there are in fact three separate genes at different loci81
Therefore, we feel it will be easier if we discard the use of T except for the Ticked
Tabby and use Mc and Sp82 instead83.
The following table may be useful for future reference.
Tabb
y
Pattern
Former
Gene
code
Updated
Gene code
Notes
Ticke
d
Ta
Ta If this gene is present the cat will
show as a ticked tabby regardless of any
other tabby genes they may have.
Mack
erel
T Mc Can only be seen when Ta is not
present. Dominant over mc
Class
ic
tb mc Recessive to Mc
Spott
ed
Ts
Sp
This is a modifier gene, effective only
when Ta is absent. Sp breaks up the
79 The natural “wild” gene that is the basis of the tabby cat. 80 Genetics Society of America, 2009. 81 A locus is the exact position on the chromosome where the gene is located 82 See Robinsons Genetics section on Tabby and Non-Agouti. 83 This convention has also been adopted by the GCCF and the Asian BAC.
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patterns of Mc and mc.
Figure 10
It is difficult when producing an introduction to the Agouti cat such as this, to
know just how much detail we need to go into, too much would take up far too
much space and time. Whilst, too little may mean that we do not provide enough
of a basis to allow a proper understanding.
Figure 1184
If we look at Figure 11, we should remember that all the genes along the
chromosome start life at the moment of conception.
This will really help us understand that the genes for Tabby Pattern and the
Genes for Agouti colouring are working at the
same time and affecting each other.
As the hair grows in the hair follicle eumelanin85 is produced by cells and dropped into the hair
shaft. When the Agouti gene is present it causes a
protein to join the process and as this protein
builds up in the cell it causes the production of
eumelanin to falter and suddenly the cell switches
to produce phaeomelanin86 , this process is
known as the Agouti shift.
The result is hair shafts with alternating bands of
84 There are many other Genes of Course 85 Black Pigment 86 Red pigment
Genome or Blueprint for the Finished Cat
19 Pairs of Chromsomes
Locus for Agouti Genes
2 alleles
Locus for Tabby Genes
2 alleles
Locus for Spotted
Modifier Genes
2 alleles
Locus for Colour Genes
2 alleles
Locus for Inhibitor Genes
2 alleles
Locus for Masking Genes
2 alleles
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yellow and black colour, ending with black tips.
Whilst the Agouti gene is busy creating these banded hairs, if the cat has also
inherited the tabby genes Mc or mc, these genes set up in competition with the
Agouti gene, stealing patches of skin and follicles and reducing the amount of
Agouti protein produced in these patches. The shift from black to red on the hair
shaft does not happen. Instead these patches of hair show as groups or patterns
of black hair beautifully offset by the Agouti coloured, ‘ground colour’ hairs. These
patterns are of course the well known Tabby patterns.
At this point it seems prudent to mention something discovered during our
research regarding the Agouti shift87.
According to Robinson the Agouti shift, switches pigment between eumelanin and
phaeomelanin. However, there is an argument that the pigmented hair shaft does
not shift from eumelanin to phaeomelanin, but instead the Agouti protein cause
the hair granules to thin and shred, it is this weakening in the granules that
causes the banded hair colour to fade to the yellow/orange colour alternately.
The UCLA Davis website does refer to the Agouti shift but does not confirm the
mechanism for the colour change.
Finally on this point, current opinion suggests that the colour of the Agouti band
can be influenced by ‘Rufus’ type polygenes These Rufus factors have not been
identified but breeders have been able to select for them to reproduce warmer,
richer background colors in the Tabby. Selective breeding in the Brown Tabby is
producing a rich redder background colour.
87 We have used many sources and resources for our research; wherever and whenever opinion
differs we have fallen back on Robinson’s Genetics for Cat Breeders and Veterinarians as our base reference. However, it must be noted that the latest edition was produced in 1999. Where there has been compelling evidence that evidence has changed we have sought to validate opinion and have found the UCLA Davis website invaluable.
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9.1. Ticked Tabby
9.1.1.Ticked Tabby (All colours) Non Silver (Preliminary)
If you decided to play a game of ‘scissors, paper, stone’, against a Brown Ticked
Tabby, you would lose. This beautiful cat is, genetically, at the top of the
domesticated feline tree.
Whilst it is generally accepted that Felis Silvestris or Felis Lybica, both striped
cats are the original UK wildcat species, it is less well known that the first
domesticated or companion cats were probably ticked tabbies, imported as pets.
These early imports were crossed with the British Shorthair to create the cat
known today as the Abyssinian.
The ticked coat can be seen in the Somali and Singapura breeds as well as the
Abyssinian. At first glance the entire cat will appear to be one colour until one
gets closer and notices that in fact each individual hair has alternating bands of
colour giving rise to a flecked appearance.
The British Ticked Tabby can be bred in all self colours including tortie.
Genes for Coat
Ticked Agouti Colour Coat Dilute Tabby Orange
Dominant B A- B-/bb-/bb¹
C- D- Ta- oY/oo
Dilute B A- B-/bb-
/bb¹ C- dd Ta- oY/oo
Dom/Tortie A- B-/bb-/bb¹
C- D- Ta- Oo
Dilute/Tortie A- B-/bb-/bb¹
C- dd Ta- Oo
A- can be: AA or Aa D- can be: DD or Dd
C- can be: CC or Cs Ta- can be: TaTa or Tata
Any Tabby Pattern may also be carried see Figure 10
Ticking results when the agouti gene (A) causes the individual hairs to have
bands of light and dark pigmentation. As the hair starts to grow, the agouti gene
allows full pigmentation into the hair shaft, it then causes a sudden stop and the
hair shaft goes lighter, the process then turns back to full pigment for a bit
longer. As the hair reaches its full length this process known as the Agouti shift
stops. The result is a hair shaft that has dense colour at the tip, then a band of
yellow to orange, then a band of dense pigment, fading to yellow or orange at the
base.
What is special about the Ticked feline is that they carry a dominant gene for
Ticking (Ta) and when Ta is present it prevents other feline tabby patterns from
developing. However, like all tabbies, it may have tabby markings on the face and
agouti hairs on the body.
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This cat shows a ticked pattern showing the stripes
and markings on the head, legs and tail.
This cat is likely to be Heterozygous for the Ticked
Gene Tata
This cat has no tabby markings on either his body or
tail – he is likely to be Homozygous for the Ticking Gene
TaTa.
Eyes
Copper, orange or deep gold
The Show Cat
The coat should be evenly ticked with two or three bands of colour extending well
down the hair shaft ending with the base colour at the roots. This ticking may be
heavier along the spine line and extend down the length of tail. The face, legs
and abdomen clearly show the base colour and on the head the ticking may be
more dense, or even solid in kittens, which may clear to an ‘M’ on the forehead.
Other facial markings are as per standard British Classic Tabby standard.
Necklaces may be broken or unbroken but a lack of these is not a fault.
Apart from the underside of the abdomen, which should be spotted, the body
should be free of spots stripes or blotches.
The tail may be ringed with complete or broken rings or have a continuation of
the darker colour of the spine line, the tip of the tail being the same colour as the
markings. In adults the legs may or may not be barred.
Markings –the ticking should be of the appropriate colour affording a good
contrast with the base colour. The Base Colour should be even in all areas other
than the lips and chin, which may pale significantly, but should not be white and
should not extend down the chest. Tarnishing or discolouring of the silver base
colour is undesirable.
Figure 14
Figure 12
Figure 13
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This variety of British Shorthair arrived unexpectedly in 2007, in a litter born to
an experienced breeder88 of Tabby British Shorthair.
The following section is a little lesson in genetics to help explain how this sweet
baby arrived:
A lilac British Shorthair Stud cat imported from Sweden with a genotype of:
Colour Agouti Tabby Black Full Coat Dilute Orange White
Lilac
Sire aa Ta89 bb C- dd oY ww
Was mated to
Colour Agouti Spotty Black Full Coat Dilute Orange White
Choc’-
Spotty
Dam
A-
Sp
bb
C-
Dd
oo
ww
The resulting kitten Inherited:
Genes From Dad From Mom Note
Agouti aa A Mum’s dominant agouti gene prevailed
Tabby Ta - Although non-agouti, the sire’s ticked tabby gene is
dominant for underlying base
pattern.
Spotted - Sp The mother’s spotted gene
will override any other Mc or mc genes.
Black bb bb Chocolate
Full Coat C C Full Coat
Dilute d D 1 copy of dilute so kitten is Chocolate
Orange o o No red gene to have
White w w No white gene to have
88 Mrs Celia Leighton (Porteous) 89 Ticked tabby
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The only really surprising thing about this entirely natural production of a
delightful chocolate ticked tabby is that it hasn’t happened more often.
Best Practice and Recommendations
• Whilst breeds are in the preliminary stages it is best leaving the
development to experienced breeders and those breeders working in
breeding groups.
• When working with the gene for ticking, try to understand the pedigree
of the cat, remember that any cat that is Homozygous for ticking can
only throw Ticked kittens. (When the cat is Tata, heterozygous, the cat
is most likely to have bars and markings on the legs, tail, face, etc)
• You may be able to tell what colour a tabby is by looking at the color of
its stripes and its tail tip.
• The agouti shift, describes a process where the switch between dark
and light pigment happens suddenly. But there are also variations in
just how often the ‘switch’ turns on and off, Ticked tabby breeders are
looking for as many bands of colour on each hair shaft as possible, this
can vary between 4 and 6, but up to 8 have been reported90.
• The Wide Banding91 gene can play havoc with the ticked bands,
causing the dark hair to the tips – avoid mating shaded or tipped cats
in a Ticked breeding program.
• Breeders should experiment for the Rufusing gene, it is evident from
the great variety of colours in the Agouti ground colour that polygenes
are able to produce coats that range from rich creamy oranges through
to pale washed out greys. Mating cats with good ground colour to cats
with good ground colour is advisable.
• Remember that although this variety is new to the British, other
breeders have extensive experience of working with the genes for
Ticking, personal knowledge transfer is invaluable.
• Breeders may find that despite their best efforts, the ticked gene will
cause the agouti colour on the muzzle and throat to pale almost to
white.
90 Chaos and Confusion genes may be at work see Tipped section. 91 Theoretical at present
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9.1.2. Silver Ticked Tabby (Preliminary)
The Silver Ticked tabby cat is essentially the agouti cat the Ticked tabby with the
addition of the Inhibitor gene for Silver (I)
This colour can be seen in other breeds such as the Abyssinian and the Somali. In
fact all the silver Abyssinians bred in Britain today are descended from an
outcross to a British Silver Spotty in the 1960’s.
Despite the British input to other breeds,
the Silver Ticked is not yet a common
sight in the British Section.
However, they are being bred and indeed
shown – A rather lovely tortie-silver has
appeared at several GCCF shows.
92
Eye Colour
Green or Hazel.
Genes for Coat
As the non-silver Ticked plus the dominant (I). The gene
for Silver (I) changes the rich Agouti ground colour to a
cooler sparkling silver.
The Show Cat
In silvers the colour of the ticking may lack warmth and
this should not be penalised.
Best Practice and Recommendations
Remember that it is possible to breed silvers with every colour of ticking, and
some of the paler varieties in other breeds can be very pretty.
If we peep over our shoulders into the Asian Breeding Policy, it suggests that
mating non silver to non silver and silver to silver ticked produces the best
results93
92 Photo by Milt Webb 93 Of course our gene pool is tiny as yet
Figure 15 An American
Silver Ticked Tabby
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9.2. Mackerel and Classic Tabbies (non Silver)
The basic ticked coat is quite common and can be seen in mice and rabbits. The
feline has developed a secondary system of pigmentation which creates dark
stripes flashed throughout the ticked coat94. These stripes or patches are caused by genes that ‘fight’ with the Agouti gene
(A), and effectively ‘stop’ the agouti protein from performing the agouti shift, in
some patches of the skin, thus preventing the eumelanin to phaeomelanin shift95. Hair shafts in these patches only have the darker colour. This leads to an
impression of one dark-coloured pattern superimposed upon another pattern.
The genes responsible for these dark patterns are either Mackerel (MC) which is
dominant over (mc).
The face of the British Tabby can
be beautiful, and the markings
should be clearly defined and
dense. On the forehead there
should be a letter 'M' giving the
impression of a frown. There
should be an unbroken stripe
running back from the outer
corner of the eye and narrow lines
on the cheeks.
On the neck and upper chest there should be unbroken necklaces, the more the
better. The edges of the ears to be the same colour as the markings with a
central patch of ground colour resembling a thumb-print.
Muzzle and Throat
It is worth mentioning the colour of the chin and lips of the tabby. Sometimes
there can be a reduction in the pigment in this area, such that the ground colour
can appear almost white. Whilst we can expect that the ground colour will pale
from the chin to the throat, breeders should try not to use cats that show ‘white’
in this area in their breeding programs.
94 Probably for camouflage 95 If indeed it is phaeomelanin!
Brown Classic tabby at 6 weeks
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9.2.1.Mackerel Tabby
The non-silver series Mackerel Tabby is not often seen on the British Show bench.
However, the Mackerel pattern is probably the ancestral striping pattern, which is
seen in the African wild cat (Felis libyca) and the European wild cat (Felis
silvestris).
The stripes are always vertical, and gently
curving, on the body, ringing the tail, and
lining the legs. The Mackerel pattern can be
found in any of the self colours, but the
pattern of the stripes will always remain the
same.
Genes for Coat
Mackerel Tabby
Agouti Colour Pattern Dilute Tabby Pattern
Orange
Dominant B A- B-/bb-
/bb¹
C- D- Mc- spsp
tata
oY/oo
Dilute B A- B-/bb-
/bb¹
C- dd Mc- spsp
tata
oY/oo
Dominant O A- C- D- Mc- spsp
tata
OY/OO
Dilute O A- C- dd Mc- spsp
tata
OY/OO
Dom/Tortie A- B-/bb-
/bb¹
C- D- Mc- spsp
tata
Oo
Dilute/Tortie A- B-/bb-/bb¹
C- dd Mc- spsp
tata
Oo
A- = AA or Aa Mc- = McMc or Mcmc C- = CC or Ccs
Eyes
In copper, orange or deep gold, with no trace of green
The Show Cat
The SOP calls for a narrow unbroken central spine line, on either side of which is
a broken spine line from which the narrow lines which form the Mackerel Pattern
run vertically down the body; these lines should be as narrow and numerous as
possible. The tail rings, which should be as narrow and numerous as possible,
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may be complete or broken with the tip of the tail being the same colour as the
markings.
Markings of the appropriate colour to be clearly defined and dense in colour,
without brindling, affording a good contrast with the ground colour. The colour
should reach as near the roots as possible.
Ground Colour, should be even, in all areas other than the lips and chin, which
may pale significantly but should not be white.
Best Practice and Responsible Breeding and Recommendations
• Some Breeders believe that the Mackerel Tabby makes the best ‘base cat’
for Spotted Breeding Programs – believing that Spots are more numerous
when they break the Mackerel Pattern rather than the Classic Pattern
• Conversely – some breeders believe that the Mackerel pattern in the
British doesn’t actually exist – being instead poorly marked Spotties!
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9.2.2.Classic Tabby.
Also known as the blotched tabby, this tabby pattern
is recessive to the Mackerel pattern. The ticked hairs
alternate with the solid hairs making the pattern that
is so much loved by breeders. The recessive, mutant,
mcmc causes the dark pigmented hairs to form
thicker stripes, which travel horizontally across the
cat's body, often swirling and creating spirals.
The Classic tabby pattern without silver, is not seen very often on the show bench
which is a great shame, because, the combination of pattern and agouti colour
presents a super playground for breeders as we can see in other non- British
breeds on the show-bench96
Genes for Coat
As for Mackerel tabby, just substitute Mc- for mcmc.
As we have learned throughout the sections, genes are never as simple as they
might seem, they really do work with groups of mates, either as yet unproven
genes or polygenes. Experienced breeders see something in a cat that they really
like and selectively ‘breed’ for that trait, in doing so they not only select the
‘obvious’ genes for Classic Tabby, they are also selecting97 some ‘best friend
genes’ that enhance or subtly alter the phenotype.
This is probably the right time to present some of these hypothetical modifier
genes.
‘Best Friend Genes’ (Hypothetical)
1. Rufous genes – Everybody wants to be in with this gang (except perhaps
silver breeders)98 – this lovely group are thought to make the agouti pale
colours warmer and richer and dark colours darker – what more could any
tabby breeder want from her mates? It seems that Rufous modifiers can
get more intensive over successive generations. Fabulous news for
breeders’ intent on selection over many generations.
2. The Tabby Pattern Size modifier - Breeders may recognize this group of
‘friends’ who seem to alter the Classic Tabby Pattern by creating pale
areas within the blotched markings.
96 Have a wander around the show-benches and have a guess at the genes underneath the coats. 97 Often without really knowing it 98 See section on Silver Tabbies.
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The reason the Classic tabby appears so infrequently probably lies in it’s recessive
qualities, in the scissors, paper, stone game – the classic tabby loses out to the
hugely popular Silver series, the not so sought after Mackerel pattern, the
Spotty99 and of course the Ticked tabby.
The Classic, comes in all the colours of the self, Black, but just to confuse we call
it the Brown tabby, Blue, Chocolate, Lilac, Cinnamon, Fawn and of course Red
and Cream.
The Brown tabby in the wild has a sort of murky appearance, the agouti banding
is evident, but the pale bands are cool and greyish.
Generations of
breeding the
pedigree tabby has
produced a cat with
rich dark browns
for the eumelanin
pigment and warm
orangey tones for
the phaeomelanin.
See how the
colours on these
sweet litter
brothers differ from
each other.
The Show Cat
Breeders are after four things:
1. Pattern – On the forehead there should be a letter 'M' giving the impression of
a frown. There should be an unbroken stripe running back from the outer
corner of the eye and narrow lines on the cheeks. On the neck and upper
chest there should be unbroken necklaces, the more the better. The edges of
the ears to be the same colour as the markings with a central patch of ground
colour resembling a thumb-print.
A series of lines runs from above the 'M' marking, over the top of the head
and extends to the shoulder markings. The shoulder markings form the
outline of a butterfly, when viewed from above. Both upper and lower 'wings'
should be clearly defined with the central areas broken by small areas of
ground colour. On the back there should be an unbroken line running down
the spine from the butterfly to the tail, and there should be a stripe on either
side of this, running parallel to it. These stripes should be separated from
each other by stripes of ground colour. On each flank there should be an
'oyster-shaped' patch which should be surrounded by one or more unbroken
rings.
The tail should have complete rings, as numerous as possible, with the tip of
the tail being the same colour as the markings. The legs should be barred
evenly with bracelets from the body markings to the toes which are spotted.
Markings on the hind legs extend (when adult) from the soles of the feet, up
99 See section on Spotted Tabby.
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the back of the leg, to the hock. The abdominal region should also be spotted.
Ground colour and markings should be evenly balanced and both sides of the
cat should have identical markings.
2. Markings – These are the dark pigmented areas, creating the ‘pattern’ these
markings must be solid in colour and sound to the roots they may be black or
various shades of brown. The depth of pigment should be the same from the
facial drawings through to the tip of the tail. And if that isn’t enough, breeders
must not allow any stray agouti hairs to drift into the markings, so no ticked
or banded hairs.
3. Ground Colour – This is the agouti ticked ground colour against which the
pattern is presented. The warmer and richer breeders can get this ground
colour the better.
4. Type – Of Course!
Best Practice and Recommendations
• There can be no doubt that breeding classic tabbies is a job for those with
patience, but as we can learn the benefits of exploiting all these polygenes
can be just so rewarding.
• As we learn more about cat genetics we can begin to see that sometimes
we cause a conflict for ourselves. Silver tabby breeders have over the
years worked really hard on getting that wonderful classic tabby pattern to
stand out clearly against a crisp silver undercoat. In doing so they have
bred out polygenes for Rufousing, because these polygenes probably
cause the silver to tarnish, in doing so any non-silver Mackerel or Classic
tabbies in the litter will be short of those lovely colour enhancing
Rufousing chaps and the results may be poorly coloured well patterned
kittens.
• Breeding programs for show quality non silver tabbies and silver tabbies
may benefit from some separation100.
100 Experienced breeders will already have separate breeding programs.
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9.2.3.Spotted Tabby (non-silver)
The Spotted tabby is exactly what it sounds like and comes in the same colours
as the Classic tabby. This popular variety of British Shorthair offers breeders the
same challenges as the Classic tabby, with spots on!
Genes for Coat.
Spotted Tabby
Agouti Colour Pattern Dilute Tabby Pattern
Orange
Dominant
B
A- B-/bb-
/bb¹ C- D- Mc-
mcmc Sp- tata
oY/oo
Dilute B A- B-/bb-
/bb¹ C- dd Mc-
mcmc
Sp-tata
oY/oo
A- = AA or Aa Mc- = McMc or Mcmc C- = CC or Ccs Sp- = SpSp or Spsp
Note: The genes for coat are as for Mackerel tabby, but spsp becomes Sp-
Naturally occurring Spsp is the spotting or modifier gene. Sp is dominant over Mc
– and mcmc and causes the basic
tabby patterns to break into spotted
patterns. Mackerel tabby patterns
will have more, smaller spots which
run in vertical lines. The Classic
tabby will have larger spots that are
scattered more randomly.
A beautifully marked brown spotty
baby
(Now do we think these spots are Mackerel or Classic based?)
The Show Cat101
The pattern on the body and legs
should consist of numerous, well
101 The pattern is often less obvious in the dilute cats
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defined, oval, round or rosette-shaped spots which follow the tabby pattern in
distribution.
9.2.4.Silver Tabby, (All colours)
The Silver Tabby and Spotted British Shorthair is the second
most popular variety, with more than 14% of registrations
being this wonderful cat.
Silver Tabby Breeders aim to produce the Classic and
Spotted Patterns in all the usual Self British Colours.
The Silver tabby is essentially the same cat as the Classic
tabby with the addition of the dominant Inhibitor gene, (I)
introduced in the Smoke section. But this time the Inhibitor
gene gets to come out to play with the Agouti gene (A) and
with quite spectacular results.
In the Silver Tabby, agouti hairs have colour or pigment at
the tip, but the remaining hair shaft is stripped of agouti
colour by the I gene, leaving a sparkling silver grey. The
solid hairs have normal colouration. Breeders are seeking
the greatest contrast between the now almost-white agouti
hairs and the markings made by the fully pigmented patches of hair.
Genes for Coat
Silver
Tabby
Agouti Colour Pattern Silver Dilute Tabby
Pattern
Orange
Dominant B A- B-/bb-
/bb¹ C- I- D- Mc- spsp
tata oY/oo
Dilute B A- B-/bb-
/bb¹ C- I- dd Mc- spsp
tata oY/oo
Dominant O A- C- I- D- Mc- spsp tata
OY/OO
Dilute O A- C- I- dd Mc- spsp tata
OY/OO
Dom/Tortie A- B-/bb-
/bb¹ C- I- D- Mc- spsp
tata Oo
Dilute/Tortie A- B-/bb-
/bb¹ C- I- dd Mc- spsp
tata Oo
A- = AA or Aa Mc- = McMc or Mcmc C- = CC or Ccs Sp- = spsp I=II or Ii
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Eyes
We have all heard about the influence of polygenes on coat colour and pattern.
But polygenes also come together to help us with eye colour. The Black Silver
Tabby should have green or hazel eyes, whilst all other colour of silver tabby
should have copper orange or deep gold.
The Show Cat
Just to keep us on our toes the British Breed Standard for the Classic Tabby
pattern is more exacting than that in the American Shorthair. The pattern
requirements for the Silver Tabby are as for the non-silver tabby. The key to the
show cat is clear, sharp markings, against an untarnished silver backdrop.
Best Practice, Responsible Breeding and Recommendations
The Silver series British Shorthair benefits from a breeder group that has
developed an extremely high standard. But popularity within a breed can
sometimes lead to inexperienced breeders producing kittens that ‘let the side
down’. In safe hands the Inhibitor gene can sparkle, but it also has a tendency to
tarnish, and there are three schools of thought as to why.
1. The Inhibitor gene does not work alone and has a bunch of polygene
friends, sometimes some of these friends do not pull their weight and the
result is a poor silver colour.
2. Breeding cats can be Homozygous for Silver (II) or Heterozygous (Ii) and
effectively carrying the genes for Brown. Some breeders believe that it is
the genes for non-
silver that ‘show
through’ and spoil
the show.
3. When a non-
silver parent is used
in a silver breeding
program, if that
non-silver parent
carries a large dose
of those lovely (if
you want them)
Rufousing genes,
then those
Rufousing genes
can cause the silver
to tarnish.
The good news is that all of the above can be dealt with by careful breeding
selection. But, as with all breeding programs, it is not a quick fix, breeding a high
quality line takes years of patience.
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9.2.5.British Silver Spotted Shorthair.
This stunning cat is hugely popular. Genetically, breeders take the Silver Tabby,
either Mackerel or Classic, add the Spotty gene and the result is quite simply
stunning.
Genes for Coat
See the table in the Silver
tabby section and
substitute sp for Sp.
Because the Spotty gene
Sp- sits at a separate
location from Mc- or
mcmc, unless your
breeding cats are Homozygous for Spots, litters can be full of both tabby and self
kittens.
Whilst we cannot be certain if the breeder was hoping for more spotted kittens,
the Queen will love them all equally.
The Show Cat
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Judges are looking for SPOTS, lots of them, and please make them as dramatic as
possible.
3 A beautiful Queen snoozing on show afternoon.
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10. Tipped – Silver Series
10.1. Black Tipped
In the 1970’s a Chinchilla (longhair) was mated to a British Silver Tabby102. A
breeding program ensued, which included the British Blue and other cats from the
silver series, culminating in the development of the Black Tipped as we know it
today. This was recognised as a distinct British type in 1978.
The ‘Tippy’ can be bred in any of the British colours. However, it is the gorgeous
Black Tipped that is seen out most often.
At this point it
would be lovely if
we could just say
that genetically
the Black Tipped
is just a slightly
complicated
version of the
Silver Tabby,
throw in a pretty
picture and move
right on.
But, that would
be taking the
easy way out.
If we start with the Simple Genes for Coat:
Black
Tipped
Agouti Black Full
Coat
Dilute Silver Tabby
Pattern
Orange
A- B- C- D- I- Ticked Ta- Mackerel Mc- tata Classic mcmc tata Spotted Sp- tata
oY/oo
A- = AA or Aa B- = BB or Bb or Bbl C- = CC or Ccs
D- = DD or Dd I – II or Ii Wb- can be: WbWb or Wbwb
We can see that this looks an awful lot like the Silver Tabby series and yet the
Tippy looks so different. This ‘difference’ that breeds true has led breeders and
102 The pioneer of this program was Norman Winder of the Peerless prefix
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geneticists to refer to a hypothetical gene commonly referred to as the Wideband
gene (Wb). In essence it seems that the Wideband gene works with the agouti
gene and causes a hiccough in the agouti shift, such that the on /off switch turns
the eumelanin switch on, then ‘off’ suddenly but leaves the phaeomelanin switch
‘on’ for longer, causing a wider than normal agouti band. The Silver Inhibitor
gene then joins the party causing the hair shaft to lose the colour, thus leaving
an almost totally silver cat with black (or other colour) tipped hair shafts.
It seems that this hypothetical Wideband gene can only work with agouti cats as
it is the agouti shift that causes the colour change on the hair shaft – that the
Wideband gene then forces into a wider band.
It would also appear that when teamed up with either the Inhibitor gene I-
(Silver) or the Rf- genes for rufousing the Wb- gene is Incompletely Dominant.
At this point it may help if we understand Incomplete Dominance –
Firstly, the cat must be a hetrozygote (two different copies) for the allele in
question – and is a condition that expresses itself by showing a phenotype
(appearance) that lies somewhere in between the phenotype of the two parental
phenotypes.
So, for example, a Black Tipped cat with a good expression of the Wideband gene
(probably Homozygous for Wb) is mated to is mated to a Brown Tabby –
The offspring will be heterozygous for Wideband, Rufousing and Inhibitor. The
resulting litter may well include Silver Shaded cats with pretty orange noses!!!
With the following genotype A- B- Tata or tata Mc- Sp- or spsp Wbwb Ii Rfrf
Sometimes we can distinguish those cats that are homozygous from those that
are heterozygous by studying these little phenotypical clues.
We know that there are many genes that we cannot yet test for, but that we can
‘see’ such as the Inhibitor gene (I) – and it is widely accepted that these genes
are present and one day we will have tests for them.
However, The more ‘theoretical’ genes e.g. Rufousing require a greater act of
faith, and it is important that we as breeders understand the counter argument.
The argument for the presence of genes such as Wideband and Rufousing is the
exploitation of polygenic traits by careful selection.
The first breeders of the Black Tipped bred cats which had significantly heavier
tipping than we see today. By selecting parent cats with less tipping and clear
undercoats, subsequent generations of Black Tipped cats have evolved with wider
intermediary (yellow) agouti bands.
Therefore, we should keep our minds open to the question – how are breeders
achieving the wide range of tipped bands that we see?
• Are we dealing with complex polygenes that are happy to let us clear
undercoats and minimize the expression of black pigment to produce our
Tippies
• Is there an Incompletely Dominant Wideband gene?
• Or has the agouti gene mutated to allow better and better suppression of
pigment production?
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Because it makes discussion easier – we will embrace the theoretical Wideband
gene throughout this breeding policy! But we will also accept that even the
Wideband genes will have help from those polygenes!
Eyes
Black Tipped - Green. In all other colours Copper, Orange or Deep Gold. The
skin outlining the eyes to be appropriate to the colour of the tipping.
The Show Cat
This silver cat, most often in the form of the Black Tipped, can be shown in any of
the standard British colours including tortie.
The colour is restricted to
the ends of the hairs in
the form of tipping and
the undercoat is so pale
as to appear white. The
coat on the back, flanks,
head, ears and tail should
be tipped with colour.
The tipping should be
evenly distributed and it
is the even distribution
rather than the degree of
tipping which is of
paramount importance.
Heavily tipped cats must
not be penalised as long
as the tipping is even and
free from tabby
markings: in fact, they are preferable to cats with so little tipping that they are
almost white.
The legs should show tipping which will decrease towards the paws, but which
should be as even as possible. The chin, stomach, chest and undertail should be
as pale as possible.
Nose Leather and Paw Pads
Nose Leather - Brick red preferred, outlined in colour appropriate to the colour
of the coat tipping.
Paw Pads - Appropriate to the colour of the coat tipping.
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Some Extra Genetic Information
Under the GCCF we breeders in the UK do not have to worry about the distinction
between Silver Shaded or Silver Shell (more lightly Tipped) instead Tippy
breeders can happily breed for personal preference, with the emphasis on
evenness of colour.
To what extent Tippy breeders can influence their preferences by using genes for
pattern, is still the subject of much debate - Let us remind ourselves what the
agouti shift does to affected hairs – remember that the hairs that make up the
darker ‘pattern’ remain a solid colour – but in Agouti cats there are areas of coat
wherein the hairs have bands of colour or tipping – and the Wideband gene can
only work on hair shafts that have these bands of colour –
If we look back at the table for genes for coat on page 83 we can see that the
Black Tipped cat like all other agouti (and non agouti) cats has a base pattern, of
either Ticked, Mackerel/Classic tabby or Spotted. It is important that we picture
this – because it is this base pattern that is affected by the Wideband gene.
We know that the Chinchilla is predominantly based on a Classic pattern
Some breeders believe that the Tippy sparkle that can be observed in some lines
is due to as yet unidentified ‘sparkle’ genes such as the Glitter in the Bengal. The
Tippy sparkle can best be seen in October when the new undercoat comes
through!
Best Practice and Recommendations
• Breeding show quality Silver Series Tipped – is quite simply not easy. In
the British Section there are a few dedicated breeders producing kittens of
excellent type – but the gene pool is very small and it is difficult for
breeders to make improvements without making a sacrifice of some sort.
• As litters are born breeders should look to see if they can detect the base
pattern of their kittens and keep records as to which base pattern results
in the best Tippy pattern.
• The Ticked gene as a base pattern is causing some excitement amongst
breeders and there is a sense that the ticked base pattern may offer the
best opportunity for evenness of ticking. (Breeders working with the ticked
gene should note that when the cat has two copies of the ticked gene it
will override all other agouti patterns)
• Black Tipped Breeders may wish to consider keeping a Black only line -
undoubtedly – cats that are Homozygous for silver (II) produce the best
Black Tipped coats – free of tarnishing.
• Breeding Tipped to other colours of BSH may help type – but first
generation will not make show cats – they will probably be too dark. But
hopefully second generation will pull back.
• Just for fun Tippy breeders could experiment with the other Tipped
colours!
• Some Tippy breeders would welcome more definitions of ‘Tipped’ such as
Shaded, Cameo, Shell etc.
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10.2. Golden Tipped including all Non-silver Series Tipped.
As each BAC prepares a breeding policy for the breeds within their remit, it
provides a fresh opportunity to study the registration policy and the standard of
points in conjunction with the breeding policy.
Overtime, as new generations of kittens are born, breeders gain an increasing
awareness of the genetics at play in their cats and new genetic information
becomes available or is updated.
For us in the British BAC it is the Non-silver series of Tipped British that is
presenting us with some of the most interesting genetic puzzles – but first we will
explain the genetic make-up of the Golden Tipped as seen on our show benches.
To that end we will start with the show cat!
The Show Cat
This is the non-silver version of the British Tipped in which the hair is a rich
golden apricot colour, sound to the roots with black/dark brown tipping. The coat
on the back, flanks, head, ears and tail should be tipped with colour. The tipping
should be evenly distributed and it is the even distribution rather than the degree
of tipping which is of paramount importance. The legs should show tipping which
will decrease towards the paws, but which should be as even as possible. The
chin, stomach, chest and undertail are a pale apricot colour.
Eyes - Green. The skin outlining the eyes to be black/dark brown.
Nose Leather - Brick Red, may be outlined in black/dark brown.
Background and Genes
Genes for coat
Golden
Tipped
Agouti Black Full Coat Dilute Silver Tabby
Pattern
Orange
A- B- C- D- ii Ticked
Ta-
Mackerel
Mc- tata
Classic
mcmc
tata
Spotted
Sp- tata
oY/oo
A- = AA or Aa B- = BB or Bb or Bbl C- = CC or Ccs
D- = DD or Dd I – II or Ii Wb- can be: WbWb or
Wbwb
If we look carefully at the above table we can see that the only difference
between the Golden Tipped and the Silver Tipped is the fact that the Dominant
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Inhibitor gene (I-) is in its ‘switched off’ state. This absence of a gene in the
dominant state is sometimes referred to as being ‘recessive’.
What this tells us is that we have a cat that has a genotype that is
indistinguishable from the Brown Tabby and yet looks nothing like his genetic
twin.
If we just confirm that which we know about this beautiful cat – he is:104
• Genetically Black, (with
Chocolate and Cinnamon
Possible)
• He could carry dilute, so blue,
lilac and fawn offspring
possible.
• He is Agouti for sure, but he
may be Homozygous AA or
Aa.
• Somewhere he will have a
tabby base pattern (we know
this because all cats do) – and
that will probably have been
quite obvious to his breeder
when he was a kitten – but
without carrying out some
test-matings we just don’t
know what he carries
But how we get from the Brown Tabby to the Golden is a subject of much conjecture.
Five Theory’s
• There is a gene for Golden
• The Inhibitor gene forces a tabby pattern to the coat tips, but when the silver
gene is not passed on to offspring, the result is a ‘Golden’ tipped instead of
‘Silver’ tipped cat.
• A Wide-band gene, exploited by Chinchilla breeders, causes a wider agouti
band that allows us to see more of the ‘yellow’ pigment.
• Years and Years of breeders working on producing the silver and golden
Persians have perfected a polygenic mix of both agouti and inhibitor genes.
• Rufousing Polygenes working in conjunction with any of the above!
A Gene for Golden?
Some breeders working with the Golden gene do
believe that there is a separate gene for the Golden
colour -
Can this Golden gene be separated from the Agouti
gene? –
Perhaps this is something that breeders could work
on?
104 This is also true for the Black Tipped – but add the Inhibitor Gene
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Golden and Inhibitor Gene
Many breeders believe that it is in fact the Inhibitor Gene (ii) that forces the tabby
pattern to the tips of the coat – but that in its ‘recessive’ state it does not restrict the
melanin or colour from the hair shaft – a theory that suggests the Silver gene is in a
sort of sleeping rather than switched off state – (There are anecdotal accounts of
Golden cats producing Silver offspring)
The coats of Golden cats look very similar to the Silver series Tipped, with dark
tipping or shading. However, the ground colour or undercoat is a warm cream which
combined with black tipping produces a wonderful 'golden' appearance. This warm
creamy-red undercoat proves that the Silver gene is not present (and we know that it
cannot be carried)
Wide-banding, Rufousing and Polygenes
The Golden Tipped, seems to strengthen the argument in favour of a separate gene or
set of polygenes, for ‘widebanding’ independent of the Silver Inhibitor Gene.
Although, it must be pointed out that the Silver (I-) gene does seem to have the
effect of widening the wideband to create the ‘Shell’ effect of the Chinchilla, whereas
the Golden’s ‘tips’ bleed more deeply into the hair shaft to produce an effect that is
more of a black smudge than a tip.
But Golden breeders must always remain grateful to those past Chinchilla breeders
and the newer BSH Black Tipped breeder’s, because it is the selective breeding over
many many generations for clear, wide Silver bands that has set the stage for the
appearance of the Golden trump card, Rufousing!
Rufous genes are the second theoretical genes that are thought to be a critical part of
what makes the Golden so special. Rufism is a term describing the genetic or
polygenetic factors that breeders have been able to select for that allows them to
produce ever warmer ground colours in non-silver agouti cats.
Essentially, the amount of rufousing determines whether a brown tabby cat will have
a warm brown pigment or a colder grey colour.
The impact that these Rufous genes can have is very important when breeding for
colour. And it certainly seems as if the effect is accumulative the more one breeds for
Rufism the warmer the tones on Brown and Red cats.
So, we have either a Black Tipped with the Silver gene switched off and a good dose
of Rufousing or we have a Brown Tabby, with a big dose of widebanding that allows
us to exploit that Rufousing!
All this now sounds quite simple! – but actually breeding the Golden is more
complicated than it might first seem – which is why we do not see many examples on
the Show bench and there are two main reasons for this:
1. Many Golden Tipped breeders breed Golden’s as a ‘by-product’ of a Black
Tipped program – and whilst the exploitation of Wideband is very good for
both silver and non-silver series, the Golden badly needs that dose of
Rufousing, which is really counter-productive to Silver breeding.
2. The Wideband and Rufousing genes are incompletely dominant and as such
just don’t breed true in the early generations of a breeding program. There
are many breeders who have been present at the birth of a much anticipated
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‘golden’ litter only to find that they are looking at a litter of very sweet, but
poorly marked Brown Classic tabbies or Spotties.
Best Practice and Recommendations
• Golden breeding is not for the short term breeder. Persian breeders have
taken many years to achieve the beautiful Golden Persians we see today.
• Homozygous seems to be the answer, Homozygous for Agouti, Wideband and
Rufous – will all help to breed true!
• It seems that the greater the Rufousing dose, the less contrast we get
between ground and marking colour.
• Understand your base pattern - On neonate tipped kittens we can usually see
signs of tabby/mackerel/spotted/ticked patterns.
• Keep meticulous records – these kittens have a habit of changing – many is
the ‘Brown Spotty’ kitten born to Golden parents – that slowly turn into lovely
Golden adults.
• Try to run some kittens on to understand your lines.
• Keep Golden series separate from Brown or Silver unless you need to ‘go out’
for genetic diversity – in which case be prepared to spend time ‘undoing’ any
effects of Incomplete dominance!
• Remember that Golden kittens can be born to non Homozygous for Silver
Black Tipped parents –
• Avoid the red- gene – novice breeders already confuse well rufoused Spotties
from Tipped to Spotty matings with Tortie/Tabbies.
The Genetic Puzzle
Earlier in this section we alluded to puzzles, conjecture and theoretical genes, none of
which are for the faint hearted –
Unlike the long term Persian breeding programs that have produced the Silver and
Golden longhairs – the Tipped British is still in its infancy. Whereas the Chinchilla
Persian is very likely to be Homozygous for Agouti, Black, Silver and Wideband –
generations of ethereal cats breeding true, we cannot be certain without testing what
the British Golden gene pool looks like – and of course whilst we can test for the
Agouti gene we cannot yet test for the Tabby base pattern.
There is a great deal of argument about the relationship between Wideband and Silver
– The ‘Golden’ suggests that the two are separate. There is also an argument that
says we cannot have Wideband without the Agouti shift, because there is no ‘band’ to
widen - but the Smoke is a non-agouti cat, with the Silver gene and there is a ‘band’
before the colour kicks in – not very wide – but it is there all the same.
Tipped breeders, along with Colourpointed breeders are increasingly becoming
interested in the properties of the Ticked tabby or the Ticked base coats.
Golden Tipped breeders are intrigued by the dilute Golden, the really rather beautiful
Blue Golden The creation of the gentle shades of warm, but pale cream tipped with
the softest tones of pale blue combine to produce one of the most gorgeous cats
imaginable. And this colour-way works much better within the Golden program than
the Black tipped.
What all this adds up to – is that we have de-stabilized the genetics that the Persian
and Abyssinian breeders have spent many generations to ‘fix’ – and we now have to
put our time in to get these beautiful Tipped cats to a point where we can predict
what we will get in our litters.
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.
This little Blue Ticked Tabby appeared in a litter.
The Golden Tipped sire’s genes were AA, Tata B
Dd ii WbWb – so homozygous, for Agouti, and
Wideband, Black, carrying dilute. Non Silver and
hetrozygous for Ticked.
The Dam was a simple lilac colourpointed105.
We could have expected this kitten to show some
widebanding and certainly much more tabby
markings – but apart from her facial markings
and one necklace – this little girl had no tabby
markings at all –
More recently breeders are adding the colourpointed gene into the Golden Mix with
some intriguing results. Kittens with very definite, golden ears, noses and testicles!!!
– can this all be down to the agouti shift?
Another issue for breeders of the non-silver Tipped series, is Type and Coat. This
combination of genes just loves to have either long fluffy coats or very short almost
oriental coats – and getting round faces, eyes and cheeks is hard won!
The Golden tipped and the newer, as yet, unrecognized Blue Golden represents a
great deal of genetic interest to the dedicated breeder. They are a lovely sight on the
show bench and breeders producing good examples deserve a hearty congratulation.
Now, anybody still hungry for genetic challenges can do some research on the late
colour change phenomenon!!!106
Précis from Robinsons Genetics on Wide Band107
The following extract gives Robinson’s opinion on the Wide Band debate
The presumed effect of the gene is to widen the agouti band on the hairs. In addition, the gene is said to make the tabby pattern less distinct or blurred. The overall effect is a tabby of a rich golden hue. Examination of hairs from golden tabbies reveals that the hair shafts are nearly completely yellow with a black tip, with a suggestion of pale blue at the base.
This is just as would be expected for a wide band phenotype. The breeding data to
substantiate the existence of the wide band gene are slim; but the gene has been theorized as a dominant (either complete or incomplete) and has been provisionally
symbolized by Wb However, the apparent difference between silver tabbies and chinchilla silvers, and thus brown tabbies and goldens, could be easily explained by polygenetic
effects on the quantitative expression of the agouti and inhibitory proteins. As the level of these inhibitory proteins increases pigment production is reduced. A chinchilla
golden is simply brown tabby with such high amounts of agouti protein production that the agouti-shift occurs very early during hair growth. This inhibitory effect is so strong that it causes the shade of yellow pigment seen in the agouti band to change to a lighter
colour characteristic of golden cats.
105 Was she a Ticked based Colourpointed? 106 More incomplete dominance perhaps! 107 Where there is a genetic ‘argument’ we the BAC will ‘present’ Robinson’s view
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11. Colourpointed
11.1. Colourpointed, Non-silver, without white spotting
The Colourpointed British Shorthair is a huge success story. During the 1980’s a
group of breeders decided to
cross the Colourpointed
Persian with the British Blue
and the result today is a
beautiful cat that has the
third highest108 number of
registrations, with only the
self and the Silver Tabby
series ranking higher.
So successful is this breed
that it boasts its own club,
which holds a championship
show annually.
The colourpointed in the UK is registered in all the colours of the British Shorthair
except the Tipped Series.109
The genetic codes behind this beautiful cat are the same as those in all the other
sections except for a variation of the gene on the C110 Locus – so we will
concentrate on this gene.
However, before we start to examine gene codes we need to sort out some
misunderstandings regarding the common names for this gene.
The colourpointed Persian carries what we commonly call the Siamese gene. The
longhaired colourpointed cats were originally bred using Siamese breed stock.
What this means is that the genes that we use in the British Shorthair are the
same as those in BOTH the Persian and the Siamese.
Also known as the Himalayan gene we shall refer to the gene in our beautiful cat
as the Siamese gene.
The ‘C’ gene governs the expression of ‘full coat’ and is a dominant gene. The
Siamese pattern is believed to be a natural random temperature sensitive
mutation that occurred hundreds of years ago in Siam.111 It is thought that all
colourpointed cats have descended from this original mutation.
Basically the C gene is required for the production of any pigment.
108 8% of British Shorthair Kitten Registrations 2009 109 April 2011 110 Also called the Albino Locus – we shall call it the Full Coat Locus 111 Now Thailand
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There are five alleles (forms) of this gene: Full Colour C, Burmese cb, Siamese cs,
blue-eyed albino ca and albino c.112
The mutations of C are all a form of Albinism and pointed cats are what we call
partial albinos. The Pointed mutations are temperature sensitive mutations, which mean that the
C gene, is only active at low temperatures.
The gene code for our colourpointed cats is cs (Siamese)
The other genetic mutations of the C gene as shown in the following table.
Table 4
C – Full Coat Genotype Description Phenotype
C/C Homozygous - Solid Coloured Solid colour C/- Heterozygous - Solid Coloured
carrying a single copy of a
recessive.
Solid colour
c/c Albino with pink eyes White with pink eyes ca/ca Albino with blue eyes White with pale blue eyes cs/cs Siamese Colourpointed Colourpointed, Siamese pattern cb/cb Burmese/Sepia Burmese pattern cb/cs Tonkinese – Co-dominant
Himalayan/Burmese
Tonkinese pattern
So in summary:
• The full colour form (allele) C, is Wildtype, dominant, and produces a full
expression of the coat colour
• The Siamese form cs, is recessive to C, co-dominant with the Burmese form,
cb and dominant to the blue-eyed albino ca and albino c. The albinism
produced by this form is more temperature sensitive than cb, causing the
classic Siamese pattern with blue eyes.
• The Burmese form cb, is recessive to C, co-dominant with the Siamese form Cs, and dominant to the blue-eyed albino ca and albino c. This form of the
gene produces a slight albinism. Black becomes dark brown. It is best known
in the Burmese breed, which has green or green/gold eyes.
• The blue-eyed albino form ca, is recessive to C, cb and cs but dominant
over the albino allele. Cats will show an almost complete albinism, with
washed out blue eyes and pigment free, translucent white coat.
• The albino form c, is recessive to all the other forms producing a pink eyed
complete albinism.
Whilst complete albinism is very rare in the domestic cat, partial albinism is
common. These partial albino patterns are temperature sensitive mutations.
112 Some scientists dispute that both c and ca exist – and that there is only one
recessive for pure albino.
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Temperature Sensitive Mutations
In order to understand the mutation we need to go back to the Wildtype form of
the gene. The C gene is the Wildtype, the term Wildtype is sometimes used to
refer to the most common phenotype (or genotype) found in the natural
population.
The C allele or form of this gene is a gene with a job to do, and is usually kept
busy producing an enzyme called Tyrosinase, and all the other forms of C have
become lazy and have become ‘loss of function’ alleles. When a gene form loses
function an enzyme or other protein may no longer be produced, or may be
produced in a different form or at lower levels or indeed may become
nonfunctional.
What has happened with our Cs gene is that Tyrosinase is still produced, but the
enzyme they produce does not work at core body temperature. Instead pigment
is only produced at below-average body temperatures.
Because of the uniform warmth in the
mothers womb, Colourpointed kittens
are born with almost pure white coats
on a pink skin.
Where blood circulation is at its most
efficient keeping the kitten warm the
coat will remain white. Parts of the
body with lesser blood circulation will
begin to activate pigment.
By the time the kitten is 3-5 days of
age, colour will begin to form on the
ears, feet and tail. The darker the
base colour the more quickly the
colour will form. With the red/cream
series being the last to show their true
colours.
Over the next few weeks and months, pigment continues to form on the coolest
parts of the body. Eventually colour creeps, from the feet up through the legs,
and the mask bleeds out from a smudgy nose to form that famous colourpointed
mask.
Specific Health - Eyes
Colourpointed cats are undoubtedly popular. And on the whole these
temperature-sensitive partial albino genes are thought to be a beautiful and
largely benign mutation. However we would be derelict in our duty if we did not
touch on some of the issues behind those lovely blue eyes.
This is a complex topic, not yet fully understood, but we will do our best.
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For those people who share their lives with colourpointed cats, they can see them
playing and hunting in the same way as other cats. For Breeders and exhibitors
the spectre of Nystagmus or a squint is never far away.
Many breeders understand that these eye problems are linked to the
colourpointed gene, which is correct; it seems that the mutated Tyrosinase found
in temperature-sensitive albino cats does not act to pigment the eyes. This is why
all cats with true colourpointed genes will have blue eyes.
The absence of pigment or melanin means that the eye does not develop properly
in the womb. As the foetus develops, some parts of the eye, including the crucial
optic nerves become disorganized and the result leaves the cat with problems
with focusing and depth perception.
We humans, with our eyes facing forwards have what is known as binocular
vision – our eyes are wired to our brains via our optic nerves – and this set up
allows us to integrate the things seen by each eye into a single image.
Most birds and reptiles have their eyes on either side of their heads and have
panoramic vision – the effect of this is that, each side of the brain only ''knows''
about the visual input from one eye,
Most cats have their eyes wired to their brains in the same way that we do but
this is not true of the colourpointed cats – their optic nerve fibres do not cross
properly in the brain113 and many end up connected to the wrong side of the
brain, in a way that is much more similar to the birds and reptiles.
What we cannot know is the exact extent to how the visual fields of our cats are
affected, and how they compensate for the mix-up in their wiring – but we can be
certain that they cannot have full binocular vision and this may impact on their
perception of distance.
In addition to this criss-cross wiring problem, partial albinism can also cause
other vision problems including: Congenital Strabismus and Nystagmus.
Congenital Strabismus
In simple terms this means a squint, and we will deal only with the squint as it
occurs in the colourpointed cat.
When a cat with a Siamese gene has an eye (or two) that points down and over
towards the nose this is called a convergent squint. When the eye or eyes point
outward, away from the nose it is called a divergent squint.
(At one time these squints were commonly seen in the Siamese breed.)
This is a permanent condition, which cannot be cured and usually appears in the
kitten at about 6-8 weeks of age.
We know that the primary cause, is an excessively high proportion of optic nerve
fibres which cross over at the optic chiasm. This causes a reduced medial visual
field. It is thought that when the kitten develops a congenital114 permanent
squint, it is a muscle imbalance caused by the kitten’s eyes attempting to correct
the distortion of the visual field.
113 Dr. R. W. Guillery, Neurophysiologist - University of Chicago 114 Condition present at birth or soon after.
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Affected kittens can be expected to have a near normal quality of life.
We also know that this permanent condition is relatively uncommon. We know
that the Siamese breeders have to all intents and purposes bred it out. This
means that it is likely to be a polygenic trait and affected kittens should not be
used within a breeding program.
Occasionally, it is possible to notice the colourpointed eye drifting in either a
convergent or divergent squint, which will correct as the cat refocuses – this can
happen on the show bench. This is not to be confused with the permanent
congenital squint
Nystagmus
It is probably true to say that virtually everyone with albinism has Nystagmus, so
it is small wonder that it crops up in our colourpointed cats with their major genes
for partial albinism.
Nystagmus is an uncontrolled movement of the eyes, usually from side to side,
but sometimes the eyes swing up and down or even in a circular movement.
There are two types of Nystagmus recognised:
1. Congenital Nystagmus, that first appears in the early months of life.
2. Acquired Nystagmus, when the condition develops later in life.
However, colourpointed breeders report a sort of mid-way partial Nystagmus that
comes and goes, usually when the cat is in a stressful state. It is probably safe to say that whatever the ‘form’ of Nystagmus we see in our
colourpointed cats it is usually due to the cross wiring of the optical nerves115
There is much that we do not know about Nystagmus in cats116 but it is likely to
be at least in part Polygenic, and kittens that show sign of a severe and or
permanent congenital Nystagmus should not be used in Breeding programs.
Most kittens and cats with severe or permanent early onset Nystagmus, will not
have eye, brain or other health problems and are unlikely to be affected by
constantly moving images, as the young brain can adapt to the condition.
Additionally neither the condition nor the animal’s vision is likely to worsen as the
animal grows up. The condition is not painful and kittens will benefit from the
normal play stimulation that most kittens enjoy.
However, they are quite likely to experience some of the following symptoms.
Breeders letting affected animals go to companion homes may wish to apprise
new families of the condition. • Nystagmus may be made worse by emotional and physical factors, such as
tiredness, unfamiliar surroundings, nervousness and stress.
115 If an otherwise normal eyed cat, colourpointed or not develops a sudden late onset
Nystagmus Veterinary opinion must be sought. 116 The GCCF genetics committee are working with the BAC’s to launch an investigation
into Nystagmus with the University of Bristol, Langford.
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• Depth perception may be reduced. Affected kittens may seem a little
clumsier than normal and may need watching if climbing higher objects.
Whilst it is important for breeders to understand the major genes that they are
working with, such that they can ensure that they always act in the best interest
of their breed, there are no contra indications to responsible breeding of the
partial albino cat. Scientists, who have studied these visual issues, have been
surprised that despite the very unusual wiring of those optical nerves, the
average colourpointed cat appears to be able to operate pretty much as cats with
normal eye/brain wiring.
Some Extra Information on the Colourpointed Cat
• The Siamese gene is recessive – both parents must either be
colourpointed or carry the colourpointed gene in order to get
colourpointed kittens.
• The Blue eye is more sensitive to bright sunlight.
• The gene that gives rise to the Siamese pattern is the same as pointed
rabbits and goats found in the Himalayas.
The Show Cat
Points Colour - Mask, ears, legs and tail should be a clearly defined colour,
matching on all points.
Body Colour - There should be a good
contrast between points and body
colour. Light shading, if present,
should tone with the points. Shading
in a mature cat should not penalise an
otherwise good exhibit.
Eye Colour - A definite clear blue;
deeper shades preferred.
Nose Leather and Paw Pads -
Appropriate to coat colour.
Showing Colourpointed Cats - Shading and Eye Colour.
We can see from the earlier sections that no matter what colour British Shorthair
one chooses to breed there are always pitfalls and the Holy Grail of colourpointed
breeding is the clear coat.
Although the standard of points says that an otherwise good exhibit should not be
penalised for shading, it also refers to ‘light shading’
The problem for colourpointed breeders is that the genes that cause pigment to
form in areas of the body that are cooler due to reduced circulation keep working
throughout the lifetime of the cat, and so as the cat ages and the circulatory
system slows down as it does with all mammals the colourpointed cat begins to
shade beyond the ‘points’ – at first it will be the shoulders and flanks and then
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gradually the whole upper body will eventually shade. Because this shading is
related to pigment, the Seal and Blue series will be most affected, followed by
chocolate.
Neutering can add to the natural slowing of the body metabolism and exacerbate
the shading on the body.
The result is that when we do see older colourpointed cats on the show bench
they will most likely be lilac!
It is frustrating for breeders who will try to campaign their young cats early
knowing that they will inevitably shade and will almost certainly be faulted for
something that is largely not polygenic.
Of course there are some lines that have managed to breed clearer coats, this
may be due to a higher metabolic rate in some lines of cats – but we only have to
look at the ratio of colourpointed kittens shown in the various colours and
compare that to the number of adult cats shown, especially in the darker colours
to know that this is an issue shared by most colourpointed breeders.
The other major headache for the British Colourpointed breeder is eye envy.
Compared to the Siamese benches with their rich array of shades of blue,
deepening to almost navy, the British colourpointed eye is often a disappointing
wish washy blue.
This is a polygenic factor and almost entirely due to the success many British
breeders have had with the orange eye.
The deeper colours of the orange eye are produced by polygenes for an increased
volume of pigment producing cells (melanocytes) and a deeper pigment.
Whereas the green eye has less pigment producing cells but also produces a lot of
pigment.
Now, this is all quite complicated but the colourpointed eye is set up in the same
way as the orange and green eye and so also has melanocytes. But the melanin
production is impeded by the fact that the eye is always warm and the
temperature never gets cold enough to produce an orange or green eye.
So what we see in the colourpointed eye is actually blue light that gets refracted
from the lens of the eye. And the less clutter in the eye, ie melanocytes, the more
blue light gets refracted and hey presto we get a deeper blue eye.
Fortunately, all this seems to be polygenic so plenty of work to do on the
colourpointed eye!
The Mask
Colourpointed breeders are seeking to produce a cat that is fully masked and
where the margins between the mask and body colour remain distinct.
Tabby colourpointed although not fully masked should still have an obvious
demarcation between the face and rest of the body.
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The ideal mask extends from
above the eyes down through
the chin and stretches beyond
the eyes evenly on both sides.
Sometimes we see a cat that
is hooded, where the mask
extends over the head and
sometimes, often on
chocolate points we see
incomplete masks, often
around the mouth and
whisker pads.
Best Practice, Responsible Breeding and Recommendations
• Colourpointed breeders should try as much as possible to understand the
major Siamese genes as discussed in this policy. • The colourpointed British has inherited a potential for long soft coats from
the Persian ancestors and a desire to have large ears and a long nose from
the Siamese ancestory – balancing
these factors to maintain good British
type is a challenge! • Breeders may wish to work with the
Colourpointed cat club to see if the
standard of points that covers all
colours of the Colourpointed is
weighted against the darker colours
on the show bench. • Experienced Breeders of the
colourpointed and tabby colourpointed
British might benefit from talking to
some of the Siamese Breeders about
their experiences of the dilute modifier
genes – too complicated to go into
here but very interesting, and
deserving of further research. • The colourpointed Queen may require some careful management, like her
Siamese cousins, she can be a precocious caller, often calling from early
January through to December, and coming back on call within weeks of
having her kittens. She may also have very large litters. Breeders will
need to manage these situations carefully. • Also in common with the Siamese the colourpointed cat is deeply
affectionate, which some people who like the British tempererment may
find needy. This affection which may translate into a deep pair bond with
her human owner, over whom she may feel possesive, may mean that
some cats may not wish to share their lives with other cats. This trait may
run in some lines.
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One last thing for the Experienced Colourpointed Breeder
If we go back to the table on page 89 Table 4 we can see that the alleles for the pink
eyed albino c and the blue eyed albino ca are recessive to the genes for the
Siamese pattern cs
There is a hypothesis that suggests that if we were to have a cat that was
genetically cs/ca we would have blue eyed colourpointed cats with a higher
contrast of colour between coat and points with a wishy washy blue eye. If any of
our lines in the UK carried this combination of genes we might see clearer coats,
but not necessarily good eye colour, breeders may occasionally see a blue eyed
albino appear in a litter if they cross back into their own lines. Although the c and
ca genes cannot be tested for and indeed some doubt whether they both exist,
any breeder suspecting that their lines may hold such a combination may wish to
keep detailed records and share these with the Colourpointed Club.
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11.2. Colourpointed -Silver Series
In previous sections we have covered the genetics behind the genes for Smoke
and Silver and also for Colourpointed. Here we are looking at cats bred with an
amalgamation of these two genes.
It is worth remembering that the Silver Inhibitor gene (I) is dominant whilst the
Colourpointed (Cs) gene is recessive.
In the UK the Smoke or Silver Tabby Pointed British Shorthair is rarely registered
with the GCCF.
However, in Europe breeders are working increasingly both with Silver and Wide-
banding in their Colourpointed Breeding programs.
Essentially, this Series reflects the simultaneous presence of both the Inhibitor
gene and the Siamese Partial Albino gene, either with or without The Agouti gene.
The Smoke or Silver Tabby Pointed Cat can come in the full range of solid and
tortie point colours.
History
It seems that the first recorded Silver pointed cats in the UK were bred in
Scotland in the 1940’s. These cats, known as Silverpoint Siamese were
introduced to the cat fancy in the 1960s. It is not clear whether some of these
cats were in fact Silver-pointed, but they were tabby pointed and in 1966, the
Tabby Point Siamese was granted recognition by the Governing Council of the Cat
Fancy (GCCF).
Smoke Pointed
The undercoat of the pigmented point colour of the Smoke Colourpointed should
pale to silver at the roots. As with the British Smoke there is a great deal of
variation in the effect of the Inhibitor gene in these cats, and breeders should
select for those with the greatest degree of contrast.
With the dominant colours, Seal and Chocolate the points may appear darker
than the non-silver series and the dilute blue and lilac colours may appear colder
with a steel effect. And other pointed breeds with the Inhibitor gene, report that
body shading is often more intense than in non- smoke individuals.
Silver Tabby (Lynx) Pointed
These cats display the main Tabby patterns on their ‘Points’ The stripes in the
dominant colours of seal and chocolate, may appear darker than the non-silvered
tabby point. Between the tabby markings the coat will appear to be silvery white.
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Again, body shading may be darker than the non-silvered cat . The dilute colours;
blue, lilac, cream and fawn may appear to have very pale points.
Silver eye ‘goggles’ may show around the eyes of the smoke and silver tabby cats
and full pigmentation may not develop until the cat reaches her second birthday.
The Problem
At the time of writing there is no test for the Inhibitor gene. If we remind
ourselves of the fact that when the Inhibitor gene (I) is present the full
development of pigmentation in the hair does not occur, and the non-agouti or
'Self' Cat turns into a Smoke, and an agouti cat becomes either a Silver Tabby or
Silver Tipped. We know that the (I) gene has a hugely variable impact, some cats
show a strong sparkling white base, whilst others show hardly any contrast and
the breeder may not see the expression of silver at all.
It is this problem with the Silver gene that has caused the GCCF to over-stamp
litter registrations with ‘Silver in Pedigree’
If we accept that Silver can be tricky to detect in the
self cat, it doesn’t take a quantum leap to understand
that with the colourpointed it can get really difficult
and with the Red series colourpointed it can become
nigh-on impossible.
In the Red-series Silver ground colour becomes Ivory and this is compounded by
the effects of the Siamese (Cs) gene
During the research for this section, we interviewed several well known European
breeders – during these interviews one breeder commented that she felt that as
soon as a test for the (I) gene is found we will have to re-register at least 25% of
all colour pointed British as Silver series.
Recommendations and Best Practice
Those colourpointed breeders interested in further research behind their
pedigrees might like to make a visit to Pawpeds – and search for a cat born in
1982 named Beeblebrox Plum Crazy – this cat was originally registered in the UK
as a Red Pointed and as such fathered a good number of offspring – he was later
re-registered as a Red Silver Smoke and Pawpeds have him as BRI ds 33.117
117 EMS Breed Numbering System
16– A lovely Chocolate Smoke Pointed Female
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There are a great number of colourpointed breeders today both here and in
Europe breeding from cats directly descended from Beeblebrox Plum Crazy118 –
and if his Silver gene slipped through the net – how many others?
We have spoken with a number of UK breeders who have experimented with
Silver in their colourpointed lines and who have decided that in the absence of a
test for the Inhibitor (I) there are no benefits to be had.
There are a number of colourpointed lines with incomplete masks around the
muzzles, with dark shaded coats and brindling of the points – and right now the
only way to determine whether your colourpointed cat is secretly Silver is to test
mate out to a self cat and evaluate the results -
118 Many Pedigrees still show this cat as red-pointed today.
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11.3. Colourpointed & White (Any colour) Preliminary
In previous sections we have covered the major genes for the Bi-Colour (White
Spotting (S) and the Colourpointed (Cs) British.
Whilst new to the British Section in the UK, the Colourpointed and White genes
are not strangers to each other and can be seen in both the Ragdoll and Snow
Shoe breeds. The Birman (a pointed cat) also shows an expression of White
Spotting (S) in the form of mittens on all four feet.
The British Colourpointed & White may be bred and shown in a mitted variety, Bi
Colour and high white/Van pattern and although all patterns are acceptable, the
pattern preferred by breeders is the Bi Colour.119
In all three patterns, breeders are looking for the White Spotting (S) gene to fall
and mask the points colour on the feet and legs, leaving four white feet. The tail
and mask will show pigment as the Colourpointed gene allows pigment to seep
into the colder points and breeders hope that that lovely white Bi-Colour blaze
will make it’s V pattern neatly in the centre of the face.
The tonal shading that often appears in the coat of a Colourpointed, takes the
form of Bi Colour markings, this area is shaded only and not solid colour.
The Show Cat
Points Colour - The face
should have an inverted V of
white, starting on the
forehead, but not exceeding
the inner aperture of the eye,
and extending down covering
the nose and whisker pads.
Symmetry of design is
desirable.
Remainder of mask, ears and tail should be clearly defined and matching in
colour.
Body Colour - There should be a good contrast between coloured Points and body
colour. Shading if present should tone with the coloured Points. Heavy shading in
a mature cat should not be penalised in an otherwise good exhibit. Bib, chest and
under body to be white. Legs should be white or have tonal shading, small
patches of colour on the legs are permissible. All four feet must be white.
Eye Colour - A definite clear blue: deeper shades preferred.
Nose leather/paw pads-appropriate to coat colour or pink.
119 The SOP does not specify the amount of white on the body.
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Some Early Findings From Breeders
The following are the observations from breeders of Colourpointed and White.
• Breeders working on this pattern are finding that after several
generations they can
regularly produce
kittens with that
perfect face blaze.
• The eyes are always
blue as in the
traditional
Colourpointed. But
some breeders are
reporting a deeper
shade of blue
amongst some of
those individuals
with White.
• When breeding for
pattern the base
colour of the
Colourpoints does
not affect the outcome.
• It doesn't matter whether you mate two Colourpointed and White cats
or a Colourpointed to a C/P and White – it seems that the litter will
usually get a mixture of both patterns120
• Two C/P and Whites together are more likely to throw a Van Patterned
C/P and White,
The Polygenic Properties of White Spotting (S)
Within the section on the Bi-Colour we touch upon the Polygenic121 properties of
the White Spotting (S) gene – Although it is often said that the Bi-Colour pattern
is completely random – we can see that the classic Bi-Colour pattern can be
worked at over generations. These Polygenic traits of (S) are proving interesting
to the Colourpointed and White breeders. The following paragraph is an extract
from the records of one such breeder.
“Certain matings of mine breed true every time, perfect markings, others are
more random. However, after previously breeding Bi-Colours, and having worked
on the Colourpointed and White, I believe that you will produce very similar
markings in the kittens as you have in the parents with White Spotting.
To within a certain percentage, say the same markings to within 10 %, meaning
more or less white either way and the markings in the same place as the parents
give or take 10%.either way - Sometimes mitted kittens are produced,
but the colour always stops where it should on the ankle, I have not known of any
C/P and White kitten developing even one pigmented paw!”
120 One experienced breeder reports when any mating contains a C/P and White she
will always have a kitten with White in the litter 121 Genes working alongside major genes that can be exploited in breeding programs
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11.4. Silver Colourpointed & White (Any colour) Preliminary
Please refer to the earlier Colourpointed sections.
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12. British Shorthair Variant
The British Shorthair we know today has a long and interesting history, we have
learned how after the major world wars breeders worked hard to restore the
breed by going out to the Persian breeds, we have read that the British Tipped
and the Colourpointed breeds have been derived from the Persian and Chinchilla
breeds.
And whilst breeders have worked for generations to get the Phenotype122 as close
to the breed standard as possible the hidden Genotype or unseen genetic makeup
of our beautiful breed has been carried from generation to generation.
One genetic legacy is the gene for long hair.
The length of fur in the feline is governed by the Long hair gene which is known
as L. In the Wild Form123 the dominant form of L codes for short hair, whilst the
recessive l codes for long hair.
To understand how hair length in the cat is determined we need to understand
the cycle of hair growth.
Anagen is the active growth phase of hair follicles. During this phase, the cells in
the root of the hair are dividing rapidly, adding to the hair shaft. Hair stays in this
active phase of growth for a genetically predetermined period of time. At the end
of the Anagen phase a
signal causes the follicle to
go into the Catagen phase.
In simple terms the
Catagen phase is a short
stage that effectively stops
the hair growing.
The final stage is the
Telogen phase, during
which the hair or fur is in its
resting state, neither
growing or shedding
The L gene works as the switch between the Anagen (growth) phase and the
Catagen (stop) phase - In the shorthaired cat, L steps in and creates the shorter
coat we know in the British, in the mutated recessive l form the switch from
Anagen to Catagen is delayed, the hair keeps growing and the longer haired cat
results.
122 Appearance 123 Typical Phenotype
Catagen phase
Telogen phase
Anagen phase
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The British Shorthair will
be either Homozygous
for Short Hair and have
two copies of L so LL or
will be Heterozygous so
Ll – any breeder mating
two Heterozygous cats
together stands a good
chance of those
recessive l’s meeting and
the result will be the
really rather beautiful
Long haired British
Variant
The British Long Hair
Although currently registered with the GCCF as a Variant of the British Shorthair
and as such cannot be shown, there is a good deal of interest in this very pretty
cat.
Variously known throughout the world as The British Long Hair, The British Semi-
Long Hair, The Britanica, The Lowlander and a bit confusingly the Highlander this
cat is described by most registries to have the same standard of points as the
British Shorthair, but with a Semi-Long coat standing away from the body.
Long Hair Mutations (extract from UC Davis)
One gene – fibroblast growth factor5 (FGF5) – determines hair length. Short hair
is a dominant trait determined by the wild-type form of FGF5. Long hair is a
recessive trait. Four mutations in FGF5 have been identified that are associated
with long hair in cats. Long-haired cats can carry two copies of the same
mutation (homozygote recessive) or have two different mutations, one on each
chromosome (compound heterozygote). Three of the mutations are fairly breed
specific, while the fourth is present in all long-haired cat breeds and crossbreds,
as follows:
Mutation 1 (M1): present in Ragdolls
Mutation 2 (M2): present in Norwegian Forest Cats
Mutation 3 (M3): present in Maine Coons and Ragdolls
Mutation 4 (M4): present in all breeds of long hair cats, including Ragdolls, Maine
Coons, and Norwegian Forest Cats.
17 - Exquisite British Longhair from Europe
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13. Eye Colour
The most common colour for wild, non colourpointed, cats is hazel somewhere on
the scale between orange and green.
The British Shorthair comes with four distinct eye colours:
They can be sorted into two categories:
• The Polygenic eye colours:
• The Major Gene eye colours:
The Polygenic eye colours:
These eye colours are not linked to major genes and breeders are able to
manipulate polygenes to produce the desired colour and intensity.
• Orange/Gold/Copper
• Green
Breeders breeding for eye colour will know that within each of those colours there
is great deal of variation in the range of colours, both in depth of colour and hue.
And the shades of orange can merge into green and vice-versa leaving cats with
the hazel eyes of their wild counterparts.
The good news is that selective breeding can influence these polygenes so, within
reason, eye colour can be stabilized. So when we see outstanding eye colour time
and time again in a line – we know that this is thanks to hard work and planning.
The Major Gene eye colours:
When eye colour is linked to a major gene it means that breeders have to work
with that colour.124
• Colourpointed Blue
• Blue
Kittens are always born with blue eyes. The final eye colour begins to develop
between 6 and 7 weeks of age. It will be at least 3 or four months before
breeders will be able to see the much longed for colour.
124 For example it is not possible to breed a colourpointed cat with an Orange eye.
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HOW EYES GET THEIR COLOUR
There are two key factors that influence eye colour in the cat:
• Pigmentation
• Blue Light Refraction
The iris has two layers of cells or melanocytes,
which produce pigment.
1. The Stroma - an outer layer made up of a
bunch of loosely constructed cells.
2. The Epithelium – situated under the Stroma
consisting of tightly packed cells.
Just like the coat colour, the pigmentation of the iris is caused by melanin and the
intensity of the colour depends on the numbers of melanocytes in the eye.
When melanocytes levels are low the eye colour will be in the green spectrum, as
the number of melanocytes increase, possibly due to selective breeding, the eye
colour will intensify to orange
When there is an absence of melanocytes, as in the un-pigmented white cat the
eye will appear blue125 - all that blue light reflecting and refracting just bounces
back -
Melanocytes don’t all produce pigment at the same rate – sometimes they can be
quite lazy – so when a cat has fewer, but lazy melanocytes the eye will be a weak
green. A black tipped, with stunning black-rimmed deep-green eyes will not have
many melanocytes but those she has will be working hard at producing pigment.
Using this logic we can understand that a cat with an iris packed full of
melanocytes all working as hard as possible will result in a cat with fabulous
copper eye colour.
The blue of the colourpointed cat is different again – the colourpointed eye could
have eyes packed full of melanocytes or not – they could be the lazy sort or not –
it won’t matter – because those melanocytes simply won’t work in the iris of a cat
that cannot produce pigment unless core body temperature falls below normal -
Additionally the light that is taken in through the cats eyes is refracted and
reflected and it is the number of fibres milling about in the Stroma level that
determines the levels of blue light that interacts with the pigmented cells – this
combination of blue coloured light playing over the pigmented cells determines
the eventual eye colour of the cat.
Fewer fibres in the colourpointed eye will result in a deeper clearer blue – the
breeder’s best chance of producing good blue eye colour is to consistently mate
cats with good blue eyes to cats with good blue eyes!
125 Or in rare cases pink
Epithelium
Stroma
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Finally, behind the retina we have the Tapetum Lucidum. This is reflective layer of
tissue that sends light back through the eye. and helps cats see in low light - it
also causes eye shine in flash photos. This layer is missing from the eyes of most
blue eyed white cats.
ODD EYES
These occur when the cat has different genes affecting each eye – if pigment cells
do not reach the eyes because they are halted by the White gene (W) the cat will
have blue eyes. However, if pigment cells reach one eye the cat will have one
orange eye and one blue eye -
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14. Record Keeping
Keeping good records is one of the cornerstone principles of a sound breeding
management system.
This section will cover the importance of keeping accurate breeding and cattery
records.
We will use the term Cattery, to help remind us that even if our cats are our
much loved pets that live in our homes, as soon as we implement a breeding
program of selected animals, a well managed system of housing and husbandry
must be planned.
Running a cattery requires a full time commitment to health and welfare. It will
require time, space, patience and financial support and critically it will require the
breeder to keep accurate and long term records.
As a minimum the following records should be kept:
Purchase Cat Records Contact
Records
Breeding Records
Record details
of all cats
purchased
Pedigree Name Name of Sire
Pedigree
records
Colour Address/Phone
number/email
address
Name of Dam
Breeder
records
Gender Relationship Inbreeding co-
efficient
Cost to
purchase
including travel
Date of
Birth/Purchase/Sale
Fellow Breeder Cost
Vaccination
records
Breeder Stud Cat
owner
Dates matings
observed
Health Care/Veterinary Used your
stud
Describe the
mating – how was
the stud/how was
the dam.
Temperament Cat Club Calculate pinking
up date
Performance as stud Judge Calculate due date
Performance as Dam Show
Management
Show Records Bought kittens
from You
Registration Number Sold kittens to
you
Genotype
DNA Tests
Nutrition
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Birthing Records
Kitten Records
Litter Records
Book Keeping
Records
Date and time
labour starts
Date and time of birth Success of
litter against
predetermined
criteria (did
you get what
you hoped
for!!)
Money In – by
type
Describe queens
behaviour/any
discharge
Birth weight Overall health
and vigour
Money Out – by
type
Time of
contractions
Any birth notes, ie
Breech etc
Number of live
kittens born
Time of first and
subsequent
kittens
Identification details Number of
kittens lost in
nesting
Time of last
kitten
Daily weight records
Make a note of
all the placentas
Nutrition
Birth weights Health records
Assistance
required by
dam/medications
Worming
Fleas
Vaccination
Show potential
Sale records/contracts
Fortunately there are a number of packaged software programs to help with
much of this information and simple spreadsheets can be used to keep and
calculate much of the required information.
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15. Recommendations
To be successful a breeding program must be undertaken in a planned,
considered and structured way, within a system or framework of accepted best
practice. However, a breeding program or system can only be as good as the
breeder who operates the system.
Good breeders will set themselves goals and objectives. They will seek to
understand the needs of the feline and ensure that they do not overcrowd or fail
to meet the needs of the animals in their care.
Breeders will need patience, creating a line needs time, and an ability to see
one’s offspring objectively. It takes courage to neuter animals with undesirable
characteristics.
Breeders can often recognize cats bred by other breeders, they can recognize a
‘line’ by its look, this not happenstance, it is the product, often of many years, of
careful planning, selection, heartache and luck.
The breeder that we all admire, will be selecting kittens that they like the look of,
that have good health and temperament. They will seek to mate their queens to
excellent stud cats in the hope that those selected queens will produce easily,
strong sound kittens that have no genetic abnormalities but do have the kind of
beauty that the breeder can be proud of. It is this balancing of genes for good
and bad that is the true test for any breeder. If we get it right, we should be able
to predict the outcomes, we should be able to produce kitten after kitten that
have such distinctive attractive qualities that unmistakably stamp them as ‘ours’
Using this breeding policy in conjunction with the standard of points and the
registration policy, breeders should be able to work with their clubs and each
other to protect and improve this wonderful breed that is so very much loved.
The GCCF draft business plan for 2011-12 includes a scoping exercise for a
“GCCF Breeder Scheme” – which will be promoting responsible breeding.
We recommend that our British Breeders support this initiative - In the final
analysis it is we, the breeder that is the custodian of the British Shorthair Cat.
© British Shorthair BAC - 2010
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Appendix 1 References
We have referred to a greater or lesser extent to the following publications. We
have also made much use of other widely available materials and are, as ever,
grateful to those who have gone before us.
GCCF Breeding Policy
Asian Breeding Policy
The Official Standard of Points (GCCF)
British Registration Policy (GCCF)
Robinsons Genetics for Cat Breeders and Veterinarians
Judges Reports (GCCF Website)
Wikipedia
Feline Advisory Bureau
DEFRA Cat Welfare Policy
PAWPEDS (www.pawpeds.com)
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Appendix 2 Glossary
Allelle refers to the different forms of a gene
Baer Test - The BAER test is based on the electrical response of the brain to
auditory stimuli. When a sound enters the ear, tiny electrical impulses are
generated by components of the auditory pathway. The signals can be picked up
by recording electrodes positioned on the head and are, in turn, passed into a
computer. The test offers quick, non invasive and accurate assessment of an
individual’s hearing status.
Blood Groups - Blood consists of red blood cells, white blood cells and plasma.
The red cells carry oxygen and their well-being is essential for life. Red blood
cells, like most other components of the body, are made of protein, and proteins
can be recognised and destroyed by the body’s immune system. The cat has
essentially two blood groups: A and B (although there is a third, very rare, group,
AB, which is a combination of the two). The red blood cell proteins are A in one
group, B in the other (see figure 1). In fact, the proteins on the surface of type A
and B red blood cells are only slightly different, but of course the immune system
can detect the difference.
Chromosomes - Genes are located on the chromosomes. All cats have 38
chromosomes in each body cell, 19 from each parent. Chromosomes appear in
pairs. With the exception of the sex chromosomes each pair is the same size and
shape.
Dominant Gene is one which is capable of expressing its trait even when
carried by only one member of a chromosome pair.
Genes - are the individual units of inheritance. Each gene (or combination of
genes) determines a characteristic that govern the eventual shape, size, sex,
colour, pattern and hair length of the individual animal. Genes work in pairs – but
the pairs do not have to be identical
Heterozygous refers to having two different alleles at a given locus on a
chromosome
Homozygous refers to having the same 2 allelles at a given locus on a
chromosome
Locus - is the exact position on the chromosome where the gene is located
Recessive Gene can only express itself when both members of the chromosome
pair contain the gene
SOP – The Standard of Points is established by Breeders and Breeder Groups,
who present them via their Breed Clubs to the Breed Advisory Committee. The
SOP is agreed by the GCCF Executive & finally by the full GCCF Council made up
of representatives from affiliated clubs. Any changes to a published SOP follows
the same procedure. The SOP is used by judges as the base criteria against which
to award placings and awards. It is the SOP that ultimately protects the Breed
integrity.
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Appendix 3 Key Genes
Agouti (A) – the natural “wild” gene that is the basis of the tabby cat. The
base agouti pattern is bands of black on a yellow background; in the cat this is
overlaid with one of the tabby patterns.
Non- agouti or “hypermelanistic” (a) - a recessive gene mutation that
turns the original “wild” tabby cat into a self black by overlaying the agouti base
colour with melanic pigment, making the whole animal appear black, although
often in certain light the underlying tabby pattern may still just be discernible.
Other genes work to change this black pigment to other colours.
Inhibitor (I) – a dominant gene that suppresses the development of pigment
in the hair of the coat, typically producing hairs that are fully coloured only at the
tip and have a silvery white base. It has greater effect on the lighter pigment in
an agouti cat, removing the yellow colour and turning the base colour white or
“silver”. In the case of a non-agouti cat the inhibitor removes colour from the
base of the hair-shaft to produce a silvery white hair with a coloured tip, i.e a
Smoke. This allele appears to interact with other genes to produce various
degrees of tipping, ranging from deeply tipped silver tabby to lightly tipped silver
shaded tabby.
Tabby patterning genes –
Mackerel (Mc) – the basic striped tabby pattern that overlays the agouti base
(ie “wild” form)
Classic (mc) – a mutation of the mackerel allele recessive to all other tabby
patterns which gives a blotched pattern with the characteristic “butterfly” motif
across the shoulders and “oysters” on flanks.
Ticked (T) – an incompletely dominant gene which removes most of the stripe
pattern leaving the ticked agouti base pattern on the body with minimal
overlaying stripes on legs, chest (necklace) and face.
Spotted (Sp) – current thinking is that it is likely that a specific single gene
causes the spotted tabby pattern, breaking up the mackerel or classic pattern into
elongated or rounder spots respectively.
Wide-banding (Wb) – this has been hypothesized either as a gene
(Robinson) or more probably a group of genes (Joan Wasselhuber, who coined
the term “wide-banding genes”): increasing evidence for their existence has led
to wide acceptance. Undercoat width genes determine the width of the undercoat
whether or not the cat has a silver inhibitor gene. The term “undercoat” used
here refers to part of the hair shaft closest to the body, and includes both guard
hairs and the shorter hairs often referred to as “undercoat” hairs. The variability
seen in the undercoat widths in cats points to the polygenetic nature of wide-
banding genes. If a single gene it is likely an incompletely dominant gene
mutation, the effect serving to push the darker, pattern colour in the cat up away
from the hair base towards the tip, turning the normal tabby patterns into a
Shaded or Tipped cat. Precisely how the agouti, inhibitor and wide-banding genes
interact on a molecular level is not clear - one possibility is that the wide-banding
genes influence the agouti protein production to remain high so that eumelanin
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pigment remains inhibited or down-regulated; another possibility is that the wide-
banding gene encodes for a second inhibitory protein that also down-regulates
eumelanin.
Long-hair (l) – a recessive gene mutation which produces a semi-long haired
cat. (still found today in the British owing to breeding legacy)
Chocolate (b) and Cinnamon (b1) – two mutations of the basic black non-
agouti gene which modifies black into dark brown or medium brown respectively
The white masking gene, (W). The "W" gene prevents the normal
replication and migration of pigment producing cells during embryologic
development. As a result, WW and Ww cats have a greatly reduced number of
melanocytes and appear white, no matter what other colour genes it may carry.
Only a cat that is homozygous recessive (ww) will express normal pigmentation.
Also called Dominant white (more properly "epistatic white" since it occurs on a
different gene to the black-based or red-based colours)
White spotting or piebald spotting gene, S/s, - has variable expression,
so that an SS cat often has more extensive white patching than an Ss cat. It is
this gene that creates the familiar white blaze across the face, a white bib, tuxedo
pattern, or dappled paws. A hypothetical Sb allele ("gloving gene") may cause the
mittens in Birman and Snowshoe breeds. Some researchers believe that there are
separate white spotting genes for distinct forms of white pattern, such as the
white locket that some cats have on their neck or bellies.
Siamese (Himalayan) gene (cs) - The Siamese colored kittens are born
completely white. The color of the mask doesn't appear until after a week. This is
due to that the cells of Siamese colored cat cannot develop any pigment if the
temperature is too high. When the kittens are in the womb of their mother's they
are warm and comfortable, and no pigment at all is developed. When they are
born it becomes cool enough for the pigment to develop on the cooler
extremities, like for instance ears, legs and tail. This temperature dependant
pigment production is called acromelanism. Acromelanism is present in other
animals, for instance in rabbits.
Orange (O) – this is a mutation on the X chromosome and is thus sex-linked.
The gene eliminates all melanin pigment (black and brown) from the hair fibres,
replacing it with phaeomelanin, a lighter compound appearing yellow or orange
depending on the density of pigment granules. The O allele is also epistatic over
the non agouti genotype; that is, the agouti to non-agouti mutation does not
have a discernible effect on red or cream coloured cats, resulting in these self-
coloured cats displaying tabby striping independent of their genotype at this
locus. This explains why you can usually see some tabby pattern on red, cream
and apricot coloured non-agouti cats, even if only on the head/face. Rufus
polygenes, as yet unidentified, affect the richness of the orange gene’s
expression.
Dilute (d) – a recessive gene which reduces and spreads out the pigment
granules along the hair-shaft and turns a black to blue, chocolate to lilac,
cinnamon to fawn and red to cream.
Dilute modifier (Dm) – a dominant gene which serves to modify the action of
the dilute gene (it has no effect on undiluted colours), it lightens and
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“caramelises” the colour turning blue into brownish-grey, lilac and fawn into pale
taupe (in all three cases known as Caramel) and cream into a warmer pinkish-
cream tone (Apricot)
Polygenes – these are collections of genes which modify the effect of the main
dominant and recessive genes above. A build up of polygenes creates a bigger
effect, for example a collection of certain polygenes increases the length and
density of the long-hair gene to create the Persian, and a build-up of polygenes
serves to enhance the effect of the main colour genes, turning the effect of the
orange gene from the sandy colour of the ginger domestic tom to the rich vibrant
red of the Red Persian, British or Asian Self. It is likely that a group of polygenes
is the reason for variation in the degree of tipping in the Shaded Tabby/Burmilla,
the polygenes working to create the band-width in interaction with the inhibitor
gene (when present) resulting in the range of pattern from tipped to heavily
shaded.
Rufus – (polygenes) as yet unidentified, can affect the richness of the
orange gene's expression.
Genes not at ‘work’ in the British Section but Useful to Know!
Burmese Colour Restriction (cb) – a mutation on the albino allele one step
up from the Siamese (Himalayan) gene. This reduces the amount of pigment
produced in the coat but, because it is thermo-sensitive, the pigment is darker at
the points and (slightly) lighter on the body; the action of the Burmese gene
causing a genetically black cat to turn sepia brown, a red cat to turn pale
tangerine.
Jun-18
Appendix 4 Contributing Breeders
Just as the British Shorthair would not be the cat it is today without the love, tireless
energy and sheer hard work that is invested by the breeders, a Policy such as this
could not be produced without help.
Our heartfelt thanks to the following contributors and all of our breeders who are
doing such a magnificent job on what is the best cat in the world.
Adrian Miller
Teknocat
Andrea Zerrilli
Willowood
Mr and Mrs A Brown
Kolinga
Ann Stubbs
Positively
Ann Greatorex
Mewzishun
Brenda Hollandt
Pridycats
Bron Keeling
Gooderick
Caroline Prout
Fergan
Corinne Ash
Jococa
Dee Wiley
Purrissimo
Denise Conway
Pampurred
Doreen Goadby
Dorothy Parry
Pinemartin
Brenda Wolstenholme
Cassandra Moss
Regents
Celia Leighton
Porteous
Christine Clayton
Malmo
Elena Nikitenko
Bastet-a-tet
Jane Best
Leonitara
Jean Townsend
Skellum
Jean Wolfe
Bumpkin
Jenny Hemming
Hinderslyne
Joanne Hewitson
Countrystyle
Julia Oughtibridge
Alejandro
June Payne
Poshpets
Hayley Wild
Apatchicats
Helen Maclay
Kruzinkal
Jackie Steele
Steeleaway
Judith MacArthur
Old Possum’s
Julie Caffel
Bluerain
Karen Holloway
Windymeadow
Lesley Tricker
Lizz Benson
Limatz
Ludmila Pankova
Photographer
Marion Wade
Rodwaye
Marilyn Storey
Skidoosh
Michelle Simpson
Althalus
Monica Acton
Idlebeck
Patrick Booth
Kolinga Cougar
Sandie Holloway
Rayanshel
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Sandra Schürmans
Aus-der-Mondberg
Sue Lorton Hobbs
Loraston
Ruta Towse
Miletree
Shirley Bullock
Suzanne Dalton
Donyosabuk
Suzanne Griss
Grisselian
Terri Callahan
Calla Cats
Tamila Aspen
British Empire Cats
Tammy Kingwell
Purrade
Veldes Carnell
Misskin
Viv Clerkin
Silvercloud