Independent regulation of endogenous and exogenous avian RNA tumor virus genes.

Independent regulation of endogenous and exogenous avian RNA tumor virus genes.

3H-Labeled complementary DNA specific for the envelope glycoprotein (env) gene of avian leukosis-sarcoma viruses was isolated by selective nucleic acid hybridization techniques, and used to analyze the expression of the endogenous provirus. The endogenous provirus in certain cell types termed chicken helper factor positive (chf+) can synthesize the envelope glycoprotein. Env DNA sequences were ...

Exogenous and Endogenous Leukosis Virus Genes

Nucleotide sequence relationships between the genomes of an endogenous and an exogenous avian tumor virus.

We have used mapping of large T1 oligonucleotides to examine the genome of Rous-associated virus-O (RAV-O), an endogenous virus of chickens, and to compare it with that of Prague strain Rous sarcoma virus, subgroup B, (Pr-RSV-B), an exogenous sarcoma virus. To extend the sensitivity of such comparisons, we have developed a system of nucleic acid hybridization and hybridization-competition combi...

Autogenous Immunity to Endogenous Rna Tumor Virus

The radioimmune precipitation assay using (3)H-labeled AKR leukemia virus was applied to the detection and quantitation of natural serum antibodies directed against endogenous murine leukemia virus (MuLV) envelope antigens B6C3F(1) and BALB/c mice, which have low natural incidences of leukemia and lymphoma, and AKR mice, which have a high incidence, were used in this study. Sera from mice of va...

Structure and specific sequences of avian erythroblastosis virus RNA: evidence for multiple classes of transforming genes among avian tumor viruses.

Two major RNA species were found in several clonal isolates of avian erythroblastosis virus (AEV) and avian erythroblastosis-associated helper virus (AEAV) complexes: one of 8.7 kilobases (kb), the other of 5.5 kb. The 5.5-kb species was identified as AEV RNA because (i) it was absent from non-transforming AEAV isolated from the same virus complex, (ii) it was present in complexes of AEV and di...