Protection of nonobese diabetic mice from diabetes by gene(s) closely linked to IFN-gamma receptor loci

Nonobese diabetic (NOD) mice carrying a segment of chromosome Ranking the d isrupted IFN-gamma receptor gene from original 129 ES cells are resistant t o development of diabetes. However, extended backcrossing of this mouse lin e to the NOD mouse resulted in a segregation of the IFN-gamma R-deficient g enotype from the diabetes-resistant phenotype, These results indicate that the protection of NOD mice from the development of diabetes is not directly linked to the defective IFN-gamma receptor gene but, rather, is influenced by the presence of a diabetes-resistant gene(s) closely linked to the IFN- gamma R loci derived from the 129 mouse strain.