KINETICS OF REENTRY OF POLYOMA PROGENY FORM-I DNA INTO REPLICATION AS A FUNCTION OF TIME POST-INFECTION

The fate of polyoma progeny Form I molecules was monitored at different times in the replication cycle. Molecules labeled by a 20-min pulse of [3H]thymidine at 20 hr postinfection (p.i.) reentered replication at a greater rate than molecules labeled at 28 hr p.i. In addition, a greater proportion of molecules labeled at 20 hr p.i. reentered replication than at 28 hr p.i. However, regardless of the time postinfection examined, progeny molecules appeared to be removed from the replicating pool approximately 3 hr following their initial synthesis. When replication was monitored by a continuous label of [14C]BUdR, labeled molecules substituted with BUdR in both strands accumulated continuously for at least 6 hr. © 1979.