The NOD Idd9 genetic interval influences the pathogenicity of insulitis and contains molecular variants of Cd30, Tnfr2, and Cd137

Previous analyses of NOD mice have shown that some genes control the development of both insulitis and diabetes, while other loci influence diabetes without reducing insulitis. Evidence for the existence of a gene only influencing diabetes, ldd9 on mouse chromosome 4, is provided here by the development of a novel congenic mouse strain, NOD.B10ldd9. NOD.B10ldd9 mice display profound resistance to diabetes even though nearly all develop insulitis. Subcongenic analysis has demonstrated that alleles of at least three B10 genes, ldd9.1, ldd9.2, and ldd9.3 are required to produce ldd9-mediated diabetes resistance. Candidate genes with amino acid differences between the NOD and B10 strains have been localized to the 5.6 cM ldd9.2 interval (Tnfr2, Cd30) and to the 2.0 cM ldd9.3 interval (Cd137).