Abstract
The fate of polyoma form IDNA generated during replication was investigated in resting BALB-3T3 cells. The experiments showed that there was extensive re-entry of such molecules into replication. This process took place over a period of several hours and appeared to be random. Progeny form I molecules must, therefore, spend some time in a nonreplicating pool before reinitiating replication. We propose that two factors affect the fate of progeny form IDNA. (i) The rate of reinitiation of progeny molecules is determined by the capacity of the initiation machinery. (ii) The extent of re-entry is determined by the availability of maturation proteins which divert form I from replication.