These congenic mice carry a 6 cM segment of Chromosome 2 from the NOR/Lt strain that includes the interleukin 1 alpha (Il1a) gene and part of the complex insulin dependent diabetes susceptibility locusIdd13.
Dr. Edward Leiter, The Jackson Laboratory
At 30 weeks of age, incidence of diabetes among both male and female NOD.NOR-Zfp106-Il1a (Idd13r, Il1aNOR)mice was significantly lower than in NOD/Lt mice, but in females was significantly higher than in NOD.NOR-D2Mit490-D2Mit144 (Idd13r, Il1aNOR),which carries a larger NOR/Lt-derived segment of Chr 2. At 30 weeks, 56% of female NOD.NOR-Zfp106-Il1a (Idd13r, Il1aNOR)mice had developed IDDM, compared to 100% of female NOD/Lt mice. By one year, IDDM incidence in females and males of the former strain had reached 62% and 25%, respectively, of that in control NOD/Lt mice. Thus, NOD.NOR-Zfp106-Il1a (Idd13r, Il1aNOR)retains the NOR allele(s) for "at least one, but not the complete set" of genes comprising the complex Idd13IDDM susceptibility/resistance locus.
Mice of a congenic strain (at N12) carrying a defined segment of Chr 2 that included the IDDM resistant allele of NOR/Lt at the insulin dependent diabetes susceptibility locus Idd13 were further backcrossed to NOD/Lt. At backcross generation N21, the truncated NOR-derived segment of Chr 2 was fixed to homozygosity in each of three lines by sib mating. NOD.NOR-Zfp106-Il1a (Idd13r , Il1aNOR) carries a 6 cM interval of Chr 2 from NOR/Lt extending from Zfp106/H3a through Il1a that includes part, but not all, of the complex insulin dependent diabetes susceptibility/resistance locus Idd13. (Serreze et al. (1998) refer to this strain as NOD.H3a-Il1NOR .)
|Gene Symbol and Name||Idd13, insulin dependent diabetes susceptibility 13|
|Strain of Origin||NOR/Lt|
|Molecular Note||This allele confers resistance to insulin dependent diabetes compared to NOD/Lt.|