Host-gene control of C-type RNA tumor virus: inheritance of the group-specific antigen of murine leukemia virus.

Genetic studies were aimed at elucidation of the mechanism of inheritance of the group-specific antigen of the murine leukemia virus. Two approaches have been used. First, a classical Mendelian hybridization experiment was performed with mice of the high-leukemia AKR strain and the low-leukemia C57L strain; the first filial (F(1)) generation hybrids, the second filial (F(2)) generation hybrids, and the backcrosses to the two parental strains. Second, a number of partially inbred lines derived from the F(2) generation of the same cross were used. The results of these studies demonstrate a specific genetic regulation of expression of group-specific antigens. Genes permissive to the expression of the antigen are dominant or semidominant to their nonpermissive alleles. It appears that two dominant genes carried by the AKR strain, but not by the C57L strain, are necessary for the presence of a complete virus; one of these controls the expression of group-specific antigen.