New gene locus modifying susceptibility to certain B-tropic murine leukemia viruses

A new gene, SRV, the dominant allele of which occurs in mice of strain C57BL, independently modifies the slope ("hitness") and level of sensitivity of the titration curves obtained when one subclass of B-tropic murine leukemia viruses is propagated on mouse embryo cells of nonpermissive Fv-1 genotypes. Replication of another subclass of B-tropic viruses is not modified with respect to hitness, and that of N-tropic viruses is not affected.