Effect of the Fv‐1 gene on leukemia virus in mouse cell heterokaryons

Abstract

Abstract The effect of the Fv‐1 mouse gene restriction of N‐ and B‐tropic mouse leukemia viruses was examined by determining the fate of the viruses in heterokaryons of permissive and non‐permissive cells. Virus expression in cultures of fused cells was analyzed by simultaneous autoradiography and fluorescent antibody assay, which permitted the detection of virus‐induced proteins specifically in heterokaryons or cells of either parental type. Heterokaryons were found to dominantly restrict both N‐ and B‐tropic virus, but not NB‐tropic virus which infects either cell type with equal efficiency. Fusion of permissive cells with non‐permissive cells at increasing intervals after infection showed that the restriction affects some virus function within at least 12 h of infection. These results indicate that the Fv‐1 gene locus, or gene product, affects some post‐penetration events required for virus protein synthesis.