Bacterial Genetics1 (Chapter 7) The beginning of Chapters 7 is largely a review of topics covered in...
-
Upload
wilfrid-frederick-bell -
Category
Documents
-
view
215 -
download
0
Transcript of Bacterial Genetics1 (Chapter 7) The beginning of Chapters 7 is largely a review of topics covered in...
![Page 1: Bacterial Genetics1 (Chapter 7) The beginning of Chapters 7 is largely a review of topics covered in Biol 131, and our focus will be on the sections beginning.](https://reader030.fdocuments.net/reader030/viewer/2022032703/56649d305503460f94a086ff/html5/thumbnails/1.jpg)
Bacterial Genetics 1
Bacterial Genetics(Chapter 7)The beginning of Chapters 7 is largely a review of topics covered in Biol 131, and our focus will be on the sections beginning with “Mutations to Genes”
How is knowledge of bacterial mutationand recombination important?
-- Evolution-- Antibiotic resistance-- Genetic engineering
How do bacteria obtain new traits?Spontaneous mutation
-- or experimentally ‘induced’
From other cells“Genetic recombination”
We will discuss the basic steps used in genetic engineering, and you should read the pertinent sections of Chapter 8.
![Page 2: Bacterial Genetics1 (Chapter 7) The beginning of Chapters 7 is largely a review of topics covered in Biol 131, and our focus will be on the sections beginning.](https://reader030.fdocuments.net/reader030/viewer/2022032703/56649d305503460f94a086ff/html5/thumbnails/2.jpg)
Bacterial Genetics 2
The Bacterial Chromosome
Basic structureDNA double helixno nucleosomes
Replication
Plasmids
DNA replication
![Page 3: Bacterial Genetics1 (Chapter 7) The beginning of Chapters 7 is largely a review of topics covered in Biol 131, and our focus will be on the sections beginning.](https://reader030.fdocuments.net/reader030/viewer/2022032703/56649d305503460f94a086ff/html5/thumbnails/3.jpg)
Bacterial Genetics 3
Genetic mutations are changes to the genetic code
Some common types and effects of mutations
chemical alterations
base substitution
deletions -- cause shift in
‘reading frame’
![Page 4: Bacterial Genetics1 (Chapter 7) The beginning of Chapters 7 is largely a review of topics covered in Biol 131, and our focus will be on the sections beginning.](https://reader030.fdocuments.net/reader030/viewer/2022032703/56649d305503460f94a086ff/html5/thumbnails/4.jpg)
Bacterial Genetics 4
What are the causes of mutations?
“Spontaneous” vs Induced
“Mutagens”
Chemicals
UV light
Ionizing radiation
![Page 5: Bacterial Genetics1 (Chapter 7) The beginning of Chapters 7 is largely a review of topics covered in Biol 131, and our focus will be on the sections beginning.](https://reader030.fdocuments.net/reader030/viewer/2022032703/56649d305503460f94a086ff/html5/thumbnails/5.jpg)
Bacterial Genetics 5
Mutations and evolution of bacteria
Do all mutations lead to beneficial changes?
Do mutations create beneficial changes in response to specific environment ‘stresses’ (such as high temperature)?
Will a beneficial mutation always spread through a population? -- under what conditions?
![Page 6: Bacterial Genetics1 (Chapter 7) The beginning of Chapters 7 is largely a review of topics covered in Biol 131, and our focus will be on the sections beginning.](https://reader030.fdocuments.net/reader030/viewer/2022032703/56649d305503460f94a086ff/html5/thumbnails/6.jpg)
Bacterial Genetics 6
The Ames test -- book doesn’t describe this well
Bioassay for chemical mutagenicity
Salmonella typhimurium used is a
His- ‘auxotroph’
“Positive selection” for a ‘back mutation’ to His+
(compare to negative selection in the book)
mutagens and carcinogens
![Page 7: Bacterial Genetics1 (Chapter 7) The beginning of Chapters 7 is largely a review of topics covered in Biol 131, and our focus will be on the sections beginning.](https://reader030.fdocuments.net/reader030/viewer/2022032703/56649d305503460f94a086ff/html5/thumbnails/7.jpg)
Bacterial Genetics 7
Bacterial Genetic Recombination
Processes by which bacterial genesare obtained from other organisms
= “Horizontal gene transfer”
Three processes:
1) Transformation
2) Conjugation
3) Transduction
![Page 8: Bacterial Genetics1 (Chapter 7) The beginning of Chapters 7 is largely a review of topics covered in Biol 131, and our focus will be on the sections beginning.](https://reader030.fdocuments.net/reader030/viewer/2022032703/56649d305503460f94a086ff/html5/thumbnails/8.jpg)
Bacterial Genetics 8
Transformation
Griffith & Avery Studies
Gene sources
‘Competent’ cells
Transformation
![Page 9: Bacterial Genetics1 (Chapter 7) The beginning of Chapters 7 is largely a review of topics covered in Biol 131, and our focus will be on the sections beginning.](https://reader030.fdocuments.net/reader030/viewer/2022032703/56649d305503460f94a086ff/html5/thumbnails/9.jpg)
Bacterial Genetics 9
Transduction
Transfer mediatedBy virus
In “Specialized transduction”Specific genes are passed
Transduction
![Page 10: Bacterial Genetics1 (Chapter 7) The beginning of Chapters 7 is largely a review of topics covered in Biol 131, and our focus will be on the sections beginning.](https://reader030.fdocuments.net/reader030/viewer/2022032703/56649d305503460f94a086ff/html5/thumbnails/10.jpg)
Bacterial Genetics 10
Conjugation
Genes carried on a F-plasmid
Process of conjugation
Loss of F+ phenotype
Plasmids can carry other genes
R-plasmids
Virulence plasmids
Other nonessential traits
Conjugation
![Page 11: Bacterial Genetics1 (Chapter 7) The beginning of Chapters 7 is largely a review of topics covered in Biol 131, and our focus will be on the sections beginning.](https://reader030.fdocuments.net/reader030/viewer/2022032703/56649d305503460f94a086ff/html5/thumbnails/11.jpg)
Bacterial Genetics 11
Hfr mediated conjugation
‘High frequency of recombination’
Plasmid integration
Consequences
![Page 12: Bacterial Genetics1 (Chapter 7) The beginning of Chapters 7 is largely a review of topics covered in Biol 131, and our focus will be on the sections beginning.](https://reader030.fdocuments.net/reader030/viewer/2022032703/56649d305503460f94a086ff/html5/thumbnails/12.jpg)
Bacterial Genetics 12
Use of Bacteria in Biotechnology
Role of plasmids
‘Cloning’ of useful genes
Bacterial ‘drug factories’
Bio-engineering of other organisms
Genetic Engineering