Genetic resistance in Japanese wild mice (Mus musculus molossinus) to an NB-tropic Friend murine leukemia virus.

Wild mice (Sk, Hz-Vl, Hz-IV Om, Mol.A, Fu, Te, and Sn) trapped in various areas of Japan were crossed with mice of inbred strains (C57BL/6, C57L, BALB/c, and C57BL/10), and their progeny were infected with NB-tropic Friend nurine leukemia virus. Ten days after infection, the spleens were weighed, examined for macroscopic focal lesions, and assayed for infectious virus by the XC test. Genetic analysis indicated that 4 of 8 mice tested had a dominant gene that suppresses the virus replication; the gene resembles the Fv-4' allele. No mice with the Fv-2' allele were found.