title: A nonconditional replication-defective mutant of the Schmidt-Ruppin strain of Rous sarcoma virus.
mesh_terms: D001354:Avian Leukosis Virus / Q000502:physiology; D001358:Avian Sarcoma Viruses / Q000235:genetics* / Q000254:growth & development; D002472:Cell Transformation, Viral; D002478:Cells, Cultured; D005814:Genes, Viral; D005816:Genetic Complementation Test; D006378:Helper Viruses / Q000502:physiology; D009154:Mutation; D011498:Protein Precursors / Q000378:metabolism; D014764:Viral Proteins / Q000378:metabolism
chemical_list: D011498:Protein Precursors; D014764:Viral Proteins