《微生物学》课程PPT课件讲稿（英文版）Lecture 10

Lecture 10 10.5 Genetic Recombination 10.6 Genetic Transformation 10.7 Transduction ·108 Plasmids

Lecture 10 • 10.5 Genetic Recombination • 10.6 Genetic Transformation • 10.7 Transduction • 10.8 Plasmids

Genetic Recombination Donor dna Endonuclease nicks DNA Binding of SsB protein SSB protein Donor Recipient DNA Development of cross-strand exchange Resolution at v sites Resolution at v sites Patches Figure 10.9 Splices

Genetic Recombination Figure 10.9

DNA Transfer Donor Recipient Transformation ◎ Free DNA Virus injection chromosome disruption Transduction DNA-containing vIruses Figure 10.11

Figure 10.11 DNA Transfer

DNA Transfer Conjugation: Plasmid transfer Plasmid-containing donor Conjugation: Chromosome transfer Donor cell with integrated plasmid

DNA Transfer

Selectable Phenotype DNA from Trp cells Trp" cells No growth on Trp cells Recombinants agar lacKing form colonies Figure 10.10 tryptophan on agar lacking tryptophan

Selectable Phenotype Figure 10.10

Transformation Bacterial Transforming DNA chromosome DNA binding protein single-stranded DNA binding protein Nuclease 日 Free nucleotides RecA protein Figure 10.13

Transformation Figure 10.13

Generalized transduction Bacterial cell Lytic cycle Phage-⑧ Transduced cell age Transducing particle host DNA within phage Transducing coa particle Bacterial cel Transduction Genetic recombination Figure 10.14 with host dNA

Generalized Transduction Figure 10.14

Specialized transduction Lysogenized cell Site of galactos genes of host DNA Phage DNA Induction Normal event. event Phage DNA circularizes and A portion of host detaches from DNA is exchang host DNA for phage DNA Detached DNA Detached DNA ooo Phage synthesi Phage sy is completed is completed nd releas Cell lyses and releases norma 9签 transducing Figure 10.15

Specialized Transduction Figure 10.15

F Plasmid S Tn1000 99.2/0 tra reqion IS2 25 oriT Figure 10.17

F Plasmid Figure 10.17

Plasmid Conjugation c○ c○ Plasmid Figure 10.18

Plasmid Conjugation Figure 10.18