Size and genetic content of virus-specific RNA in myeloblasts transformed by Avian Myeloblastosis Virus (AMV)

Abstract

Radiolabeled complementary DNA probes representing sequences specific for avian myeloblastosis virus (AMV) and sequences of different regions of avian leukosis virus (ALV) genome were used to analyze the gene content and size distribution of viral-specific RNA in AMV-transformed myeloblasts. The producer myeloblasts contained 8–10 times more copies per cell of virus-specific RNA than those of nonproducer (NP) myeloblasts. In the producer myeloblast, 35 S, 34 S, and 21 S virus-specific RNAs were detected. The 35 S RNA contained gag, pol, env, and c sequences; representing both the genomic and the messenger RNA of the helper virus. The 34 S RNA contained gag, pol, AMV, and c sequences, representing the genomic and the messenger RNA of AMV. The 21 S RNA of producer cells contained two different species: one contained env and c sequences and represented the glycoprotein messenger RNA of the helper virus; another contained AMV and c sequences and represented the subgenomic messenger RNA of AMV. In NP cells, two virus-specific RNAs were found; a 34 S RNA containing gag, pol, AMV, and c sequences and a 21 S RNA containing AMV and c sequences. Both RNAs hybridized to a probe specific for 5′ sequences of ALV. About 15% of pol sequences of virus-specific RNA in NP cells were found to be deleted.