The process of infection with bacteriophage phiX174, XXX. Replication of double-stranded phiX DNA

Intermediates involved in the replication of double-stranded phiX174 RF DNA have been identified and partially characterized. Analysis of pulse-labeled RF DNA suggests that the synthesis of progeny RF molecules involves, in part, the addition of nucleotides to linear complementary strands on a circular parental strand as template, so as to produce intermediate DNA strands of greater than viral length. Electron microscopy reveals DNA rings with "tails" and "double rings," which could be the intermediate structures. A model is postulated for the replication process.