Figure 09: Phage T4 life cycle

Adapted from K. Thiel, Nat. Biotechnol. 22 (2004): 31-36.

Figure 03B: Phage T4 plaques on a bacterial lawn

Part B © Ken Wagner/Visuals Unlimited

λ  can  enter  the  ly+c    or  lysogenic  cycle  

Figure  8.28  Adapted  from  A.  Campbell,  Nat.  Rev.  Genet.  4  (2003):  471-­‐477.  

Figure 9.12

RNA

ssDNA

dsDNA

MS2 ss ds φ6

φψ174 fd, M13

T3, T7

Mu Lambda T2, T4

Figure 19: Map of Phage φX174

Adapted from an illustration by New England BioLabs, Inc.

Figure 31: Electron micrograph of bacteriophage P1.

Photo courtesy of Michel Wurtz and the Biocenter at the University of Basel

Figure 10.14

Transducing particle (contains donor cell DNA)

Phage

Donor cell

Phage DNA

Host DNA

Normal phage

Transduced recipient cell

Recipient cell

Lytic cycle

Transduction

Normal lytic events

Recipient infected by transducing particle

Homologous recombination

Generalized  transducing  par+cles  carry  random  

bacterial  genes  

Figure  8.32  

Figure 9.16 Temperate virus

Lytic pathway Lysogenic pathway

Induction

Viral DNA Host DNA

Cell (host)

Lysogenized cell

Attachment

Injection

Viral DNA replicates

Coat proteins synthesized; virus particles assembled

Viral DNA is integrated into host DNA

Lysis Cell division

Prophage

Figure 9.18

Lambda genome

Host genes near attachment site

Host DNA

Cyclizes at cohesive ends

Site-specific nuclease creates staggered ends of phage and host DNA

Integration of lambda DNA and closing of gaps by DNA ligase

cos

att

cos

att

gal bio moa

gal bio moa

gal cos bio moa

λ phage  is  a  versa+le  cloning  vector

Figure  8.30  

Nonessen+al  gene  region  can  be  replaced    by  12-­‐22  kb  of  foreign  DNA.