Analysis of polyoma virus nuclear RNA by mini-blot hybridization.

The size and sequence composition of virus-specific RNA extracted from the nuclei of mouse cells late during polyoma virus productive infection were studied by blot-hybridization analysis of 32P-labeled RNA fractionated on CH3HgOH/agarose gels. Viral RNA molecules between approximately 0.4 and 4 times the length of a complete transcript of the 5.4-kilobase circular viral DNA were found. Less than 20% of such molecules were polyadenylylated. Although viral RNA of all sizes contained species that together hybridized to the entire polyoma genome, sequences complementary to the late region were more abundant than sequences complementary to the early region in transcripts less than 10-12 kilobases long.