Unit I Introduction to

the Science of Genetics

Agripa, Vanessa Abigail M.

Seda, Sarah Jane P.

A brief History

Of Genetics

A brief History of Genetics

• The genetics started with the work

of the Augustinian friar Gregor

Johann Mendel. His work on pea

plants, published in 1866, described

what came to be known

as Mendelian Inheritance.

• 1900 marked the "rediscovery of

Mendel" by Hugo de Vries, Carl

Correns and Erich von Tschermak,

and by 1915 the basic principles of

Mendelian genetics had been

applied to a wide variety of

organisms—most notably the fruit fly

Drosophila melanogaster.

• Led by Thomas Hunt Morgan and hisfellow "drosophilists", geneticistsdeveloped theMendelian, which waswidely accepted by 1925. Alongsideexperimental work, mathematiciansdeveloped the statistical frameworkof population genetics, bringinggenetic explanations into the studyof evolution.

• With the basic patterns of geneticinheritance established, manybiologists turned to investigations ofthe physical nature of the gene. In the1940s and early 1950s, experimentspointed to DNA as the portion ofchromosomes (and perhaps othernucleoproteins) that held genes.

Genetics Today

• Genetics Today objectives are oriented to the following aspects:

• To provide the required genetic information associated with human

disease

• To integrate related disciplines such as biology, chemistry, molecular

biology and epidemiology with modern genetics, in particular with

genomics and epigenomics

• To promote clinical application of innovative new genetic

approaches

• To offer an interdisciplinary forum for the discussion of new

developments based on genetics knowledge

• To apply genetics as an important tool for the development of new

therapeutic alternatives for the treatment of human disease

conditions

• To improve the knowledge and practice of medical genetics

Genetics Today will publish original articles, short communications,

comments, letters to the Editor, and review articles upon invitation.

Branches of Genetics

Branches of Genetics

• Cytogenetics

The heredity units or genes are formed of

DNA. These are integral part of

chromosomes. The chromosomes are

contained in the nucleus. The nuclei of germ

cells are the only bridge between successive

generations. The study of genes in the cell is

called Cytogenetics.

• Biochemical Genetics

The chemistry of chromosomes, genes and

nucleic acids and the chemistry of various

processes related to them are studied with

the help biochemistry. The branches of

science which is considered with the

biochemical study of genetic material are

named as 'Biochemical Genetics.'

Branches of Genetics

• Physiological Genetics

Genetics helps in explaining

some very important

physiological characteristics

like blood groups, Rh factor,

alkaptoneuria, sex

differentiation and sex

determination. Some

physiological abnormalities like

sickle cell anemia etc can be

explained with the aid of

genetic knowledge.

Branches of Genetics

• Clinical Genetics

Genetics has also helping in finding

out the root cause of certain diseases

like hemophilia, diabetes etc. All

these diseases are caused on

account of defective genotype.

Moreover serology and blood

transfusion are two most important

fields, where genetics has directly

assisted physiology and helped in

saving life.

• Radiation Genetics

The study of effects of radiations on

genes and the changes in their

expression is being studied widely in

the field of Radiation Genetics

Importance of Genetics

• Genetic knowledge allowed vast improvement in

productivity of domesticated plant species used for food

(rice, wheat, corn). Genetic knowledge has also been a

key component of the revolution in health and medical

care in this century.

• Bioengineering - directly altering the genetic material

of an organism

Developed by: Herbert W. Boyer and Stanley N. Cohen

Allows segments of DNA to be moved to different

locations or removed from the DNA molecule, thus

acquiring new genes and new genetic traits

• Health - About 3-5% of the world population (200 million

people) are estimated to be afflicted by serious genetic

disease

Genetic knowledge has already allowed for treatment

and genetic counseling (to prevent recurrence) of

Down’s Syndrome and PKU

Production of antibiotic resistant organisms

Bioengineering offers the hope of creating more

effective antibiotics

Human Growth Hormone-treatment for dwarfism

Genetic Engineering

• Alteration of an

individual's genotype with the aim of

choosing the phenotype of a

newborn or changing the existing

phenotype of a child or adult. It holds

the promise of curing genetic

diseases like cystic fibrosis, and

increasing the immunity of people to

viruses. It is speculated that genetic

engineering could be used to

change physical appearance,

metabolism, and even improve

mental faculties like memory and

intelligence, although for now these

uses seem to be of lower priority to

researchers and are therefore

limited to science fiction.

Application of Genetics

• Biotechnology has commercial potential in

medicine, agriculture, chemicals and the

environment. Once concerned only with the

production of genetically engineered proteins,

the commercial biotechnology industry now

includes the discovery and development of

synthetic small-molecule chemical drugs (called

biochemotechnology), gene therapy, cell

therapy, carbohydrate engineering, DNA-coated

silicon chips, and more.

• The creation of transgenic animals and plants

has generated huge markets for many countries.

Genetically engineered fish and trees are

revolutionizing the aquaculture and lumber

industries. Transgenic crops currently on the

market include soybeans, corn, cotton and

canola. In 1999, almost half the area planted to

transgenic varieties was almost half of the United

States soybean crop and about 25 per cent of

the United States corn crop. Most of the

transgenic crop varieties are either herbicide

resistant or insect pest-resistant.

• Another area of the foods market

where genetics has tremendous

potential is nutraceuticals--foods

whose nutritional value is enhanced.

The current nutraceutical market of

$17 billion is expected to grow in

five years to be worth $250 billion

annually. While nutraceutical are

popular with consumers, so-called

genetically modified foods are as yet

controversial and the health risks

associated with their consumption,

while innocuous based on available

evidence, remains a concern.

• While genetically engineered foods have yet to be

widely embraced, biotechnology in the medical

industry has exploded. Genetics has made it possible

to understand how hereditary diseases and other

familial traits are transmitted between generations.

This has provided the opportunity to advise parents as

to the likelihood of future offspring developing or

transmitting certain conditions. Examination of

embryonic fluid has made it possible to forecast

whether an embryo will suffer from certain hereditary

conditions at birth. Other medical applications

dominate the biotechnology industry. In 1997, protein

drugs of regular and genetically engineered natures

had worldwide sales totaling nearly $24 billion,

involving a bulk production of nearly one billion grams.

The recombinant share comprised only 0.5 per cent of

this bulk production. However, its share of dollars

sales, about $12 billion, comprised about 50 per cent.

Elsewhere, the industry is already developing

genome-based drugs or gene therapy strategies

against cancer, Alzheimer's disease, Parkinson's

disease, heart disease, diabetes, multiple sclerosis

and AIDS.

References

• http://www.bookrags.com/research/industrial-applications-of-genetics-wog/

• http://www.nlm.nih.gov/medlineplus/

• http://topnews.net.nz/content/212835-stem-cell-therapy-might-be-useful-treating-many-serious-diseases

• http://www.citrusextracts.com/nutra.htm

• http://www.biology-online.org/biology-forum/about827.html

• http://www.butbn.cas.cz/ccala/index.php?page=sr&bol4=b4o&bol5=b5lo&locality=Russia

• http://www.pachs.net/dialogues-with-darwin/item/100

• http://www.biocourseware.com/iphone/ghistory/

• http://www.dartmouth.edu/~bio70/

• http://psych.colorado.edu/~carey/hgss2/pdfiles/Ch%2001%20History%20of%20Genetics.pdf

• http://naturalselection.0catch.com/Files/gregormendel.html

• ^ July 20 is his birthday; often mentioned is July 22, the date of his baptism. Biography of Mendel at the Mendel Museum

• ^ "Gregor Mendel". Encyclopædia Britannica. Retrieved 21 July 2011.

• ^ a b c Bowler, Peter J. (2003). Evolution: the history of an idea. Berkeley: University of California Press. ISBN 0-520-23693-9.

• ^ Gregor Mendel, Alain F. Corcos, Floyd V. Monaghan, Maria C. Weber "Gregor Mendel's Experiments on Plant Hybrids: A Guided Study", Rutgers University Press, 1993.

• ^ a b c "The Mathematics of Inheritance". Online museum exhibition. The Masaryk University Mendel Museum. Retrieved Jan. 20, 2010.

• ^ a b c "Online Museum Exhibition". The Masaryk University Mendel Museum. Retrieved Jan. 20, 2010.

• ^ "The Enigma of Generation and the Rise of the Cell". The Masaryk University Mendel Museum. Retrieved Jan. 20, 2010.

• ^ "Mendel's Garden|[". The Masaryk University Mendel Museum. Retrieved Jan 20, 2010.

• ^ Randy Moore (May 2001 vol=27). "The "Rediscovery" of Mendel's Work". Bioscene.