FATE OF INFECTING PHAGE PARTICLES 



219 



Burgi (1956). Some of the factors which affect the efficiency of 

 transfer will now be considered. 



TABLE XIV 



Transfer of DNA from Parent to Progeny Phage 



Isotopic 

 Phage marker 



Per cent 

 transfer 



Reference 



Putnam and KozlofT (1 950) 



Lesley, French, Graham, and van Rooyen 



(1951) 

 Maal0e and Watson (1951) 

 French, Graham, Lesley, and van Rooyen 



(1952) 

 KozlofT (1952b) 

 KozlofT (1952b) 

 Hershey and Chase (1952) 

 Mackal and KozlofT (1954) 

 Watson and Maal0e (1953) 

 Watson and Maal0e (1953) 

 Watson and Maal0e (1953) 

 Watson and Maal0e (1953) 

 Watson and Maal0e (1953) 

 Hershey (1953a) 

 French (1954) 



7. Superinfection breakdown. In view of the phenomenon of 

 superinfection breakdown described above, one might antici- 

 pate that transfer of P^^ from superinfecting phage to progeny 

 would fail. This point was checked by French, Graham, 

 Lesley, and van Rooyen (1952) who infected bacteria with un- 

 labeled T2 phage and then superinfected with P^^.i^beled T2 

 phage after various time intervals. The transfer of P^^ decreased 

 from 30 per cent for simultaneous infection to 18 per cent after 

 one minute, 7 per cent after 2 minutes, and 2 per cent after 5 

 minutes. This experiment indicates quite clearly that superin- 

 fection breakdown will decrease the efficiency of transfer under 

 conditions of multiple infection unless the adsorption period is 

 made very short. These experiments were independently con- 



