title: Recombination between the defective component of an acute leukemia virus and Rous associated virus O, an endogenous virus of chickens.
abstract: The ability of the defective acute leukemia virus of chickens, MC-29, to participate in recombination was investigated by testing the ability of the MC-29 genome to donate sequences to its helper virus. The endogenous virus Rous associated virus O (RAV-O) was used as a helper for MC-29, and its genome was compared by fingerprinting to that of the original RAV-O. In three separate isolates, it was found that the RAV-O used as helper for MC-29 had acquired new sequences near the 3' and 5' ends of its genome. The new 3' proximal sequences resembled the C region found in exogenous but not endogenous avian oncoviruses, and it probably imparted a higher growth rate to the recombinant as compared to RAV-O. One isolate also showed recombination within the env gene. Because we could exclude the possibility that the recombination was with host cell information or with the original helper of MC-29, we conclude that the acquired sequences were derived from the MC-29 genome, and therefore this replication defective virus is not defective in recombination.
mesh_terms: D000818:Animals; D001354:Avian Leukosis Virus / Q000502:physiology*; D001358:Avian Sarcoma Viruses / Q000502:physiology*; D002642:Chick Embryo; D004279:DNA, Viral / Q000032:analysis; D004625:Embryo, Nonmammalian; D005814:Genes, Viral; D011995:Recombination, Genetic; D014422:Turkeys
chemical_list: D004279:DNA, Viral