title: Cloned DNA of defective avian sarcoma virus mutant LA46 encodes the cis-acting temperature-sensitive defect in replication.
abstract: Avian defective sarcoma virus mutant LA46 carries a temperature-sensitive defect in replication and transformation. To elucidate this defect, we cloned the integrated provirus of LA46. By DNA-mediated transfection, the cloned DNA induced fusiform-transformed foci in chick embryo fibroblasts without helper virus. LA46-encoded transformation-specific protein p105 was expressed in these transformants in the absence of helper virus-encoded proteins. Superinfection of the transformed cells with different helper viruses resulted in the rescue of pseudotypes. All the rescued pseudotypes retained the temperature-sensitive phenotype in virus replication and transformation, suggesting that the defect was due to a cis-acting lesion in the LA46 genome. Restriction enzyme comparison between LA46 and wild-type virus revealed sequence differences near the 5' and 3' termini of the LA46 genome, including the long terminal repeat regions.
mesh_terms: D000818:Animals; D001358:Avian Sarcoma Viruses / Q000235:genetics*; D002642:Chick Embryo; D003001:Cloning, Molecular; D004247:DNA / Q000378:metabolism*; D004261:DNA Replication; D004262:DNA Restriction Enzymes; D004279:DNA, Viral / Q000235:genetics; D003673:Defective Viruses / Q000235:genetics*; D005347:Fibroblasts; D008970:Molecular Weight; D009154:Mutation; D010641:Phenotype; D012367:RNA, Viral / Q000302:isolation & purification; D013696:Temperature; D014162:Transfection; D014764:Viral Proteins / Q000302:isolation & purification; D014779:Virus Replication
chemical_list: D004279:DNA, Viral; D012367:RNA, Viral; D014764:Viral Proteins; D004247:DNA; D004262:DNA Restriction Enzymes