Mechanism of replication of φX174 single-stranded DNA: IV. The parental viral strand is not conserved in the replicating DNA structure

Abstract

The role of the infecting viral strand in the replication of bacteriophage φX174 replicative form DNA was studied by [ 3H]thymidine pulse-labeling Escherichia coli cells infected with 2H 15N density-labeled phage. The products of a round of semi-conservative replicative form replication (in light medium) do not contain the original heavy viral strand by 15 minutes after infection or later in the presence of chloramphenicol. Similar results were obtained at earlier times in the absence of chloramphenicol. We conclude that the parental viral strand need not be conserved in the replicating DNA structure in succeeding rounds of replication.