title: Shope fibroma virus. I. Biological and molecular properties of a cytocidal and a noncytocidal strain.
abstract: The biological and molecular properties of two strains of Shope fibroma virus (SFV) were compared. SFV-I was highly cytocidal to most of the cell lines tested and produced pocks in the chorioallantoic membrane of chick embryos. By contrast, SFV-W did not produce cytopathic effects in any of the cell lines or in the chorioallantoic membrane, but it induced characteristic foci 3 to 4 days after infection. Both strains produced tumors when inoculated into the skin of susceptible rabbits. Maximal infectivity in BSC-1 cells was reached by both strains between 24 to 48 h after inoculation. Viral DNA synthesis also took place at the same time, although cells infected with SFV-I incorporated three times more [(3)H]thymidine than cells infected with SFV-W. Sedimentation analysis and hydroxylapatite chromatography of the two viral DNAs indicated that their molecular weights were similar and that both were naturally cross-linked. Digestion with three restriction endonucleases, however, revealed that they had different restriction sites. When SFV-I and vaccinia DNA were compared, the restriction patterns were more alike. Analysis of the virion structural proteins by gel electrophoresis indicated that SFV-I, SFV-W, and vaccinia virus had many polypeptides in common, although there were distinctive differences among the three viruses. Finally, the results of plaque neutralization tests with different antisera showed that SFV-I and SFV-W shared common antigens and that vaccinia antiserum inhibited SFV-I but not SFV-W. We conclude that the SFV-I genome contains information for both cytolysis and tumorigenesis. This unusual virus may be a recombinant between an orthopoxvirus and a leporipoxvirus.
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D003588:Cytopathogenic Effect, Viral; D004279:DNA, Viral / Q000096:biosynthesis / Q000235:genetics; D012776:Fibroma Virus, Rabbit / Q000235:genetics / Q000472:pathogenicity*; D006801:Humans; D051379:Mice; D011212:Poxviridae / Q000472:pathogenicity*; D014616:Vaccinia virus / Q000502:physiology; D014764:Viral Proteins / Q000378:metabolism; D014779:Virus Replication
chemical_list: D004279:DNA, Viral; D014764:Viral Proteins