Quantitation and localization of Rous sarcoma virus-specific RNA in transformed and revertant field vole cells.

Hybridization analysis of RNA from transformed clones of Rous sarcoma virus (RSV)-infected field vole cells and revertant subclones indicated the presence of similar amounts of viral-specific RNA in both cell types. Employing both a relatively uniform and representative complementary DNA probe and genomelength complementary DNA, we have demonstrated that the majority of RSV proviral DNA is transcribed into viral-specific RNA in both transformed and revertant clones. The viral-specific RNA is present in several size classes, the largest of which is genome-length 35S RNA. Studies on the intracellular distribution of viral-specific RNA indicate that both transformed and revertant cells contain viral RNA in their cytoplasm. Furthermore, the bulk of viral-specific nucleotide sequences are also associated with polyribosomes in both cell types. These data indicate that, contrary to previously reported studies with other retrovirus-revertant cell systems, the entire RSV provirus DNA is transcribed into viral RNA similarly in both transformed and revertant vole cells. Since we have previously demonstrated similarities in sarcoma-specific viral RNA in both revertant and transformed vole cells, these data collectively indicate that the loss of the transformed phenotype does not reflect changes in transcription of all or part of the RSV provirus, or the processing, transport, or polyribosome association of viral-specific RNA representing the entire RSV genome.