1. Bacterial genetics

3. Gram-positive bacteria transform DNA using a transformasome complex.
Figure 9.1 3

4. Gene Transfer by Conjugation
Conjugation is the transfer of DNA from one bacterium to another, following cell-to-cell contact.
- It is typically initiated by a special pilus protruding from the donor cell.
Figure 9.2 4

7. Figure 9.3 7

8. Figure 9.4 8

9. An integrated F-factor can excise from the chromosome.
- Aberrant excision results in an F′ factor or F′ plasmid, which carries chromosomal genes.
Figure 9.5 9

12. Hfr leu+ thr+pro+lac+bio+Sms X F- leu- thr-pro-lac-bio-SmR
What medium should we use to obtain
1. leu+ transconjugants
2. pro+ transconjugants
3. lac+ transconjugants

13. Hfr leu+ thr+pro+lac+bio+Sms X F- leu- thr-pro-lac-bio-SmR time
1. leu+ transconjugants
2. pro+ transconjugants
3. lac+ transconjugants
What are the map positions of
leu, pro, and lac?
time
No.of colonies on medium 1 2 3 5 10 8 15 28 6 20 48 16 25 68 26 11

17. Generalized Transduction
Figure 9.7 17

18. Figure 9.9 18

20. Specialized Transduction
Figure 9.8 20

21. Generalized Recombination
Figure 9.14 21

22. Figure 9.15 22

23. Figure 9.30 23

24. Mobile Genetic Elements
IS elements transfer by one of 2 mechanisms:
- Replicative or nonreplicative transposition
Figure 9.31 24