The Idd4 Locus Displays Sex-Specific Epistatic Effects on Type 1 Diabetes Susceptibility in Nonobese Diabetic Mice
- Evgueni A. Ivakine12,
- Steven M. Mortin-Toth1,
- Omid M. Gulban1,
- Aneta Valova1,
- Angelo Canty3,
- Christopher Scott1 and
- Jayne S. Danska124
- 1Program in Developmental Biology, Hospital for Sick Children, Toronto, Ontario, Canada
- 2Department of Immunology, University of Toronto, Toronto, Ontario, Canada
- 3Department of Mathematics and Statistics, McMaster University, Hamilton, Ontario, Canada
- 4Department of Medical Biophysics, Institute of Medical Sciences, University of Toronto, Toronto, Ontario, Canada
- Address correspondence and reprint requests to Jayne S. Danska, 101 College St., MaRS East Tower, Rm. 14-313, Toronto, ON, M5G 1L7 Canada. E-mail: jayne.danska{at}sickkids.ca
Abstract
The nonobese diabetic (NOD) mouse recapitulates many aspects of the pathogenesis of type 1 diabetes in humans, including inheritance as a complex trait. More than 20 Idd loci have been linked to type 1 diabetes susceptibility in NOD mice. Previously, we used linkage analysis of NOD crossed to the nonobese diabetes-resistant (NOR) strain and NOD congenic strains to map susceptibility to both spontaneous and cyclophosphamide-accelerated type 1 diabetes to the Idd4 locus on chromosome 11 that displayed a sex-specific effect on diabetes susceptibility. Here, we elucidate the complex genetic architecture of Idd4 by analysis of congenic strains on the NOD and NOR backgrounds. We previously refined Idd4.1 to 1.4 Mb and demonstrated an impact of this interval on type 1 interferon pathways in antigen-presenting cells. Here, we identify a second subregion, the 0.92 Mb Idd4.2 locus located telomeric to Idd4.1. Strikingly, Idd4.2 displayed a sex-specific, epistatic interaction with Idd4.1 in NOR.NOD congenic females that was not observed in syngenic males. Idd4.2 contains 29 genes, and promising candidates for the Idd4.2 effect on type 1 diabetes are described. These data demonstrate sex-dependent interaction effects on type 1 diabetes susceptibility and provide a framework for functional analysis of Idd4.2 candidate genes.
Footnotes
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Additional information on this article can be found in an online appendix at http://diabetes.diabetesjournals.org.
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- Accepted September 1, 2006.
- Received June 3, 2006.
- DIABETES
