The kinetics of bacterial DNA synthesis during indirect induction of prophage lambda

Summary The possibility that the processes of direct and indirect induction of prophage can be unified on the basis of a temporary inhibition of bacterial DNA synthesis has been examined. The kinetics of DNA synthesis in non-lysogenic bacteria were not significantly affected during a 60 min mating with UV-irradiated ColI drd donor cells. In contrast, direct irradiation of the bacteria with a UV dose which induced phage development with an efficiency similar to that obtained by indirect induction caused an abrupt cessation of DNA synthesis lasting for about 12 min. It is concluded that indirect induction of prophage differs from most treatments which induce directly in that it is not associated with an inhibition of host DNA synthesis.