Accelerating effect of nude gene heterozygosity on spontaneous AKR thymic lymphomagenesis.

The effect of nude gene heterozygosity on spontaneous AKR thymic lymphomagenesis was studied by comparing female littermates of AKR/Ms-nu/+ and +/+. As previously reported in nude gene heterozygotes with genetic background other than AKR, AKR/Ms-nu/+ mice had a significantly smaller thymus than the +/+ littermates. Overall incidences of thymic lymphomas were comparable in the two genotypes, but the mean latent period for lymphoma development was significantly shorter in the nu/+ mice (266.3 +/- 11.6 days) than in the +/+ mice (319.3 +/- 7.9 days). Both genotypes of mice expressed a high level of XC+-ecotropic murine leukemia virus. Expression of xenotropic virus was more variable, but there was no consistent difference in onset of virus expression or in virus titer that could explain accelerated lymphomagenesis in the nude gene heterozygotes.