Conservation of a Viral Rna Genome During Replication and Translation

In an attempt to get an answer to the question of conservation, the RNA of mature virus particles was doubly labeled by growth in the presence of N/sup 15/ and P/sup 32/. The RNA recovered after completion of lysis was banded in gradients of Cs/sub 2/SO/sub 4/. The two isotopes were recovered in the same RNA strands, corresponding in density to the N/sup 15/-RNA originally injected. The experiments were carried out under conditions which avoided the ambiguity which would be generated by the presence of nonparticipating strands or inactive virus particles. The data are consistent with the conclusion that the parental strands of an RNA virus are completely conserved during all the replications and translations required to produce a full yield of mature virus particles. Since it is very likely that the incoming viral RNA must serve as a genetic message, the results indicate that instability is not a mandatory attribute of RNA molecules which serve as programs for protein synthesis. (auth)