1. ©1999 Timothy G. Standish Bacterial Genetics Timothy G. Standish, Ph. D.

2. ©1999 Timothy G. Standish Cell Wall Cytoplasm Cell Membrane Bacteria Have Circular Chromosomes Termination of Replication Origin of Replication Chromosome

3. ©1999 Timothy G. Standish Replication End of replication Two chromosomes Original Chromosome Start of replication Theta (  ) structure Replication goes in both directions Mid replication

4. ©1999 Timothy G. Standish Binary Fission Revisited

5. ©1999 Timothy G. Standish Genetic Recombination If bacteria were incapable of genetic recombination, all members of a given species would be clones with differences arising only due to mutations in different lines If bacteria could not share genetic information as other organisms do in sexual reproduction, there would be vastly less opportunity to adapt to different environments As it turns out, bacteria are notorious for their ability to adapt; thus it is not surprising that elegant mechanisms exist for sharing genetic information

6. ©1999 Timothy G. Standish Ways Bacteria Exchange Genetic Material Transformation - Bacteria take up DNA from their environment and incorporate it into their genome (i.e., the Griffith experiment) Transduction - Movement of DNA between bacteria by viruses Conjugation - The direct transfer of DNA by bacteria usually via plasmids

7. ©1999 Timothy G. Standish Transformation Insertion Crossing over

8. ©1999 Timothy G. Standish Transduction Generalized Destruction of the bacteria’s DNA Lysis Replication of the viral genome Production of viral parts Packaging Infection

9. ©1999 Timothy G. Standish Transduction Specialized Temperate Phage Part of the bacteria’s DNA Replication of the viral genome Production of viral parts Packaging Lysis

10. ©1999 Timothy G. Standish F - bacteria Conjugation F plasmid Mating Bridge F + bacteria

11. ©1999 Timothy G. Standish Conjugation F plasmid Mating Bridge F - bacteria New F + bacteria Original F + bacteria

12. ©1999 Timothy G. Standish Transfer of genetic material Hfr Recombination F + bacteriaF - bacteria F plasmid Integration Hfr cell

13. ©1999 Timothy G. Standish Hfr Recombination F + bacteriaF - bacteria Crossing over Transfer of genetic material Interruption of conjugation Hfr cellF plasmid Integration

14. ©1999 Timothy G. Standish Hfr Recombination F + bacteria Hfr cellF plasmid Integration F - bacteria Recombinant Bacteria

15. ©1999 Timothy G. Standish

16. 3’ 5’ 3’ Transcription And Translation In Prokaryotes Ribosome 5’ mRNA RNA Pol.