title: Formation of Rous associated virus-60: origin of the polymerase gene.
abstract: The DNA of normal chicken embryos contains sequences related to the avian leukosis-sarcoma viruses. RNA-dependent DNA polymerase of these viruses is encoded by a genetic element known as the pol gene. The nature of the endogenous virus pol gene in chicken cells was investigated by testing its ability to participate in genetic recombination. Rous-associated virus-60-type recombinant viruses isolated after infection of chicken cells with strains tsLA337PR-B or tsNY21SR-A, both of which produce a temperature-sensitive DNA polymerase, also possessed the temperature-sensitive lesion. These results are consistent with the hypothesis that the endogenous viral information used for the generation of Rous-associated virus-60 is deficient in at least part of the pol gene and that the defect includes that portion represented by the lesions in NY21 and LA337. The frequency of polymerase-negative BH-Rous sarcoma virus alpha formation was not affected by the levels of endogenous viral expression, which suggests that the alpha defect is not derived from the endogenous pol gene.
mesh_terms: D000818:Animals; D001354:Avian Leukosis Virus / Q000235:genetics* / Q000254:growth & development; D001358:Avian Sarcoma Viruses / Q000254:growth & development; D002642:Chick Embryo; D046508:Culture Techniques; D005814:Genes, Viral; D009154:Mutation; D012194:RNA-Directed DNA Polymerase / Q000235:genetics*; D011995:Recombination, Genetic; D013696:Temperature; D014779:Virus Replication
chemical_list: D012194:RNA-Directed DNA Polymerase