1 Bacterial Genetics Filename Bact Gene ppt 2
1 Bacterial Genetics Filename Bact. Gene. ppt
2 Background Concepts u Structure & Function of DNA & RNA u Genetic code u Transcription & translation u Protein synthesis u Gene Regulation: operators, promotors , repressors Filename: DNA. ppt
3 Lecture Outline u Genetic Flow u Genetic change u Transformation u Conjugation u Transduction u Plasmids u Transposons
4 Genetic Flow u Between Generations of Cells u Within Cells
5 Genetic Flow Between Generations
6 Genetic flow within a Generation
7 The Genetic Code u Genetic information is stored in DNA sequences found in u Chromosomes u copy/cell u DS- DNA u Circular u Plasmids
8 Plasmid u Smaller than chromosomal DNA u Contains only a few genes u independent of chromosome u circular u multiple copies!!
9 Griffith’s Transformation Exp. u Background u Pathogenic bacteria have capsule u Nonpathogenic bacteria have no capsule u Experiment: u live inject pathogens u live nonpathogens u dead pathogens u live pathogens+dead nonpathogens
10 Bacterial Transformation
11 Live Pathogens Mouse Dies recover pathogens
12 Live non Pathogens Mouse lives Non pathogens recovered
13 Dead Pathogens Mouse lives No Pathogens
14 Live Non. Pathogens+ Dead Pathogens Live Pathogens!!
15 Genetic Basis of transformation
16 Recipient cell takes up DNA
17 Recombination Occurs
18 Bacterial Conjugation Sex and the single cell
19 Bacterial Conjugation in E. coli
20 Conjugation between F- & F+
21 Replication & Transfer of F Factor
22 F- cell converted to F+
23 F factor & Chromosome Recombination
24 F factor produces an Hfr
25 Conjugation Between Hfr & F-
26 Replication & Transfer
27 Recombination in F- Cell
28 Viral Transduction
29 Phage Infects Donor Cell
30 Bacterial Chromosome Broken Down
31 Bacterial DNA Trapped in Phage Coat
32 Bacterial DNA Infects New Cell
33 Recombination can Occur
34 Transposons u “Jumping Genes” u First discovered in corn u Genetic element u Moves other genes from place to place on the chromosome u Moved genes may be regulated differently
35 Insertion Sequence “IS 1”
36 Complex Transposon
37 R Plasmid “R 1”
- Slides: 37