The iddm4 locus segregates with diabetes susceptibility in congenic WF.iddm4 rats.
Viral antibody-free BBDR and WF rats never develop spontaneous diabetes. BBDR rats, however, develop autoimmune diabetes after perturbation of the immune system, e.g., by viral infection. We previously identified a disease-susceptibility locus in the BBDR rat, iddm4, which is associated with the development of autoimmune diabetes after treatment with polyinosinic:polycytidylic acid and an antibody that depletes ART2(+) regulatory cells. We have now developed lines of congenic WF.iddm4 rats and report that in an intercross of N5 generation WF.iddm4 rats, approximately 70% of animals either homozygous or heterozygous for the BBDR origin allele of iddm4 became hyperglycemic after treatment to induce diabetes. Fewer than 20% of rats expressing the WF origin allele of iddm4 became diabetic. Testing the progeny of various recombinant N5 WF.iddm4 congenic rats for susceptibility to diabetes suggests that iddm4 is centered on a small segment of chromosome 4 bounded by the proximal marker D4Rat135 and the distal marker D4Got51, an interval of <2.8 cM. The allele at iddm4 has 79% sensitivity and 80% specificity in prediction of diabetes in rats that are segregating for this locus. These characteristics suggest that iddm4 is one of the most powerful non-major histocompatibility complex determinants of susceptibility to autoimmune diabetes described to date.
Mordes
John P
JP
Department of Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA.
Leif
Jean
J
Novak
Stephen
S
DeScipio
Cheryl
C
Greiner
Dale L
DL
Blankenhorn
Elizabeth P
EP
D019264:Adoptive Transfer; D000483:Alleles; D000818:Animals; D002874:Chromosome Mapping; D003922:Diabetes Mellitus, Type 1 / Q000235:genetics* / Q000276:immunology / Q000473:pathology; D004195:Disease Models, Animal; D005819:Genetic Markers; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D006720:Homozygote; D007515:Islets of Langerhans / Q000276:immunology / Q000473:pathology; D010182:Pancreatic Diseases / Q000235:genetics / Q000473:pathology; D051381:Rats; D011922:Rats, Mutant Strains
D005819:Genetic Markers