TYPE-1 DIABETES AND THE CONTROL OF DEXAMETHAZONE-INDUCED APOPTOSIS INMICE MAPS TO THE SAME REGION ON CHROMOSOME-6

Quantitative trait loci mapping was used to identify the chromosomal l ocation of genes that contribute to increase the resistance to apoptos is induced in immature CD4(+)8(+) thymocytes. An F2 intercross of the nonobese diabetic (NOD) mouse (displaying an apoptosis-resistance phen otype) and the C57BL/6 mouse (displaying a nonresistance phenotype) wa s phenotypically analyzed and genotyped for 32 murine microsatellite p olymorphisms. Maximum Likelihood methods identified a region on the di stal part of chromosome 6 that is linked to dexamethazone-induced apop tosis (led score = 3.46) and accounts for 14% of the phenotypic variat ion. This chromosomal region contains the diabetes susceptibility locu s Idd6, suggesting that the apoptosis-resistance phenotype constitutes a pathogenesis factor in IDDM of NOD mice. (C) 1995 Academic Press, I nc.