Replication of Viral Ribonucleic Acid

Following infection of Escherichia coli with MS2, synthesis of parental type viral strands was preceded by the formation of complementary strands. Twenty-two minutes after infection, when the synthesis of progeny ribonucleic acid was well under way, the rate of synthesis of plus strands greatly exceeded that of minus strands. At this time there was a turnover of plus strands and little or no turnover of minus strands in MS2-specific double-stranded RNA. These results provide further support for the view that the replication of MS2 RNA proceeds in two steps. Minus strands are first synthesized with strands as template. The resulting replicative intermediate then acts as a template for the asymmetrical synthesis of progeny plus strands. In the latter process, newly formed plus strands displace their counterparts from the replicating complex.