BIOLOGICAL ORDER 



phage D.N.A. — phage proteins X repressor 



Figure 30. Prophage during Bacterial Recombination. 



Upper row: The lysogenic male (1) (repressor present) injects its chromo- 

 some and prophage into the lysogenic female (2) (repressor present). The 

 vegetative phase is not initiated. 



Lower row: The lysogenic male (4) (repressor present) injects its chromo- 

 some and prophage in a nonlysogenic female (no repressor). The vegetative 

 phase is initiated: this is zygotic induction. 



conjugation takes place in the presence of chloramphenicol, zygotic 

 induction does not take place in a large fraction of the zygotes. 

 It could be that the viral function necessary for the onset of the 

 vegetative phase is the synthesis of a protein. If this interpretation 

 is correct, it should be applied to infection and lysogenization. 



[74] 



