About   Help   FAQ
Idd7NOD/ShiLt
QTL Variant Detail
Summary
QTL variant: Idd7NOD/ShiLt
Name: insulin dependent diabetes susceptibility 7; NOD/ShiLt
MGI ID: MGI:3036765
QTL: Idd7  Location: unknown  Genetic Position: Chr7, Syntenic
Variant
origin
Strain of Specimen:  NOD/ShiLt
Variant
description
Allele Type:    QTL
Mutation:    Undefined
 
Mutation detailsThis allele confers resistance to insulin dependent diabetes compared to C57BL/10 and NON/Lt. This allele confer inhibition of intrathymic deletion of CD4+CD8+ AI4-expressing T-cells compared to C57BL/6. (J:28947, J:131557)
Inheritance:    Not Specified
Phenotypes
Loading...
View phenotypes and curated references for all genotypes (concatenated display).
Notes
Homozygosity for NOD/Lt-derived alleles confers type 1 diabetes resistance.

Mapping and Phenotype information for this QTL, its variants and associated markers

J:13557

123 polymorphic markers were screened in a backcross population of NOD/Lt x (B10.NOD-H2g7 x NOD/Lt)F1 animals to identify QTLs associated with susceptibility to insulin dependent (type 1) diabetes. 106 diabetic backcross animals and 190 non-diabetic backcross animals were used in this study. Parental strain NOD/Lt spontaneously develops type 1 diabetes whereas parental strain B10.NOD-H2g7 is resistant.

Three novel diabetes susceptibility QTLs were identified. Idd7 mapped to 4.5 cM on mouse Chromosome 7 near D7Nds6, Idd8 mapped to 2.5 cM on mouse Chromosome 14 near D14Nds1, and Idd10 mapped to 45 cM on mouse chromosome 3 near D3Nds7, D3Nds11, and D3Nds8. Idd7 and Idd8 are associated with insulitis and diabetes susceptibility. Homozygosity for NOD/Lt-derived alleles confers resistance to diabetes at Idd7 and Idd8 indicating a dominant susceptible effect of the C57BL/10-derived allele. Idd10 also shows linkage to insulitis and diabetes susceptibility.

Several previously identified QTLs were detected in this study:

Idd3 mapped to 28 cM on mouse Chromosome 3 near D3Nds1 in linkage to diabetes susceptibility and insulitis. Sequence analysis of candidate gene Il2 revealed several amino acid difference between NOD/Lt and C57BL/10.

Idd4 mapped to 43.8 cM onmouse Chromosome 11 near D11Nds1 in linkage to diabetes susceptibility.

Idd5 mapped to 19.5 cM on mouse Chromosome 1 near D1Nds6 in linkage to diabetes susceptibility and insulitis.

Idd6 mapped to 71.2 cM on mouse Chromosome 6 near D6Mit14 in linkage to diabetes susceptibility.

J:131557

Linkage analysis was performed to identify non-MHC genetic loci involved in the deletion of autoreactive CD8+ T-cells. NOD/ShiLtDvs mice carrying the H2g7 allele display loss of ability to select against autoreactive CD8+ T-cells, which contributes to development of type 1 diabetes mellitus. C57BL/6J animals congenic for a NOD-derived portion of chromosome 17 (D17Mit21-D17Mit10) containing H2g7 do not display this phenotype.

A population of 295 (NOD/ShiLtDvs x B6.NOD-H2g7)F2 animals transgenic for T-cell receptor (TCR) genes Tg(TcraAI4)1Dvs and Tg(TcrbAI4)1Dvs were created. Animals were phenotyped at 5- to 6-weeks of age for the number of CD4+CD8+ T-cells co-expressing AI4 TCR transgenes. The highest and lowest expressing CD4+CD8+ F2 animals wereselected for initial genotyping of 132 SNP markers spaced ~20 cM apart.

Highly significant linkage to loss of deletion of AI4 TCR-expressing T-cells mapped to 15 cM (30.2 Mb) on mouse Chromosome 7 (LOD=8.06). The QTL interval spans approximately 6 cM -23 cM (21.2 Mb - 43.3 Mb). This locus explains 10.47% of the variance and co-localizes with the previously identified diabetes susceptibility locus Idd7 (4 cM). NOD/ShiLtDvs-derived alleles at Idd7 confer decreased intrathymic AI4 T-cell selection.

Theassociation of Idd7 with inhibition of AI4 TCR-expression T-cell deletion was confirmed in a AI4 transgene-expressing congenic line carrying C57BL/6J-derived chromosome 17 DNA from Gpi (11 cM; 33.9 Mb) to D7Mit346 (34 cM; 58.6 Mb) encompassing the Idd7 region on a NOD genetic background. The NOD.B6-(Gpi-D7Mit346) Tg(TcraAI4)1Dvs Tg(TcrbAI4)1Dvs animals congenic displays significantly higher double-positive thymocyte numbers compared to NOD/ShiLtDvs- Tg(TcraAI4)1Dvs Tg(TcrbAI4)1Dvs animals and B6.NOD-H2g7 Tg(TcraAI4)1Dvs Tg(TcrbAI4)1Dvs animals, indicating the C57BL/6J-derived allele of Idd7 promotes normal deletion of autoreactive T-cells. The Idd7 locus also appears to regulate expression of the Tg(TcraAI4)1Dvs transgene as AI4 TCR alpha-chain expression is significantly decreased in NOD-Tg(TcraAI4)1Dvs Tg(TcrbAI4)1Dvs animals compared to NOD.B6-(Gpi-D7Mit346) Tg(TcraAI4)1Dvs Tg(TcrbAI4)1Dvs and B6.NOD-H2g7 Tg(TcraAI4)1Dvs Tg(TcrbAI4)1Dvs animals.

Suggestive loci associated with inhibition of CD4+CD8+ T-cell deletion mapped to 77.5 cM (148.7 Mb) on chromosome 4 (LOD=1.55), 39 cM (85.4 Mb) on chromosome 12 (LOD=2.77), 36 cM (60 Mb) on chromosome 13 (LOD=2.14), and 38 cM (67 Mb) on chromosome 17 (LOD=1.38). The chromosome 4 locus overlaps with previously identified diabetes susceptibility QTLs Idd9 and Idd11, while the chromosome 13 locus overlaps with Idd14.

References
Original:  J:28947 Mcaleer MA, et al., Crosses of NOD mice with the related NON strain: A polygenic model for IDDM. Diabetes. 1995 OCT;44(10):1186-1195
All:  3 reference(s)

Contributing Projects:
Mouse Genome Database (MGD), Gene Expression Database (GXD), Mouse Models of Human Cancer database (MMHCdb) (formerly Mouse Tumor Biology (MTB)), Gene Ontology (GO)
Citing These Resources
Funding Information
Warranty Disclaimer, Privacy Notice, Licensing, & Copyright
Send questions and comments to User Support.
last database update
12/10/2024
MGI 6.24
The Jackson Laboratory