Multiply branched DNA molecules from bacteriophage lambda: putative post-replicational repair DNA intermediates.

Previous studies have shown that thymidine deprivation causes the formation of multiply branched molecules among bacteriophage lambda DNA replicative intermediates. In the present report, we present supporting evidence indicating that the induction of the SOS response is involved in this process. Moreover, close inspection of the DNA replicatives intermediates present in a recA deficient strain, shows an accumulation of gapped replicative intermediates. From these observations we postulate a model by which multiply branched DNA molecules may be intermediates or derived intermediates of a post-replicational repair pathway.