Title: Environmental Microbiology Lecture 7 Genetic exchange in bacteria
1Environmental Microbiology Lecture 7Genetic
exchange in bacteria
2Why are bacteria so diverse?
Sexual recombination? Mutation? Gene exchange
(lateral gene transfer)?
3Mechanisms of genetic exchange in bacteria
4Transformation - free DNA is incorporated into a
recipient cell. - Griffiths experiments with
pneumococcus
5Mechanisms of transformation
6Transduction - DNA is transferred by a
bacteriophage. - Generalized transduction vs.
Specialized transduction
7Conjugation - Genetic transfer by cell to cell
contact. - F plasmid
8Genetic map of F plasmid
9Integration of F plasmid into bacterial chormosome
10(No Transcript)
11Transposons and insertion sequences
12Mechanisms of transposition
13Integrons Transposons able to capture and
express genes from other sources
14How to detect lateral gene transfer
- Incongruence between phylogenetic tree
- GC content
- Patterns of codon usage
- Insertion sequence determination
15Scope of HGT in bacterial genome