NOD/ShiLt(Cg)-Tg(Ins2-GAD2)2Lt/J

Stock number: 005870
Product name: NOD.RipGAD2-A line
Strain synonyms: NOD.GAD65
Research areas: Diabetes and Obesity Research, Immunology, Inflammation and Autoimmunity Research

Description

These NOD.RipGAD2-A line mice express a transgene containing human glutamic acid decarboxylase 2 on proximal Chromosome 15 and are diabetes resistant.

Detailed description

This transgene expresses human glutamic acid decarboxylase 2 cDNA under the control of the rat insulin 2 promoter. FISH analysis and pseudo-giemsa metaphase spead analysis establish the insertion site of this transgene on proximal Chr 15 near the centromere. Expression of the transgene in the islets has been confirmed by RT-PCR and Western blot analysis. Southern blot analysis confirm 4-5 copies of the transgene are present. Homozygotes are developmentally lethal. Transgene positive animals are significantly protected from diabetes onset (females- 14%, Males- 15% at 50 weeks) compared to NOD/ShiLt controls (Females- 100%, Males-50% by 50 weeks). Insulitis in 9 week old females is not significantly different between transgenics and controls.

This model provides a tool for studying at the role of autoantigens, specifically GAD2, in diabetes.

Development

Glutamic acid decarboxylase 2, GAD2 (commonly referred to as GAD65) is highly expressed in human and rat beta cells, but little to no expression in mouse beta cells. Because GAD2 is a major autoantigen candidate in human T1D, a human GAD2 under control of the rat insulin promoter 7, Ins2, was injected directly into NOD/ShiLt zygotes. In 2006, the T1DR received this transgenic strain at generation F?+33. The transgene Ins2-GAD2 encodes the human glutamic acid decarboxylase2 cDNA under the control of the rat insulin 7 promoter. This transgenic construct was injected into NOD/ShiLt oocytes and the resulting founders were backcrossed to wildtype siblings. NOD transgenic mice were backcrossed 1 generation to NOD.CB17-Prkdc^scid prior to intercrossing to make homozygote for the Prkdc^scid mutation (Bridgett et al, Diabetes 1998 47:1848-56). In 2005, the Type 1 Diabetes Resource received NOD/LtSz-Prkdc^scid Tg(Ins2-GAD2)2Lt/LtJ and in 2006 backcrossed to NOD/ShiLtJ (Stock No. 001976) to re-establish the NOD/Lt transgenic strain without the Prkdc^scid mutation.

Allele

Symbol: Tg(Ins2-GAD2)2Lt
Name: transgene insertion 2, Edward H Leiter
MGI accession ID: MGI:3603349
Generation method: Transgenic
Attributes: Inserted expressed sequence; Humanized sequence
Marker symbol: Tg(Ins2-GAD2)2Lt
Marker name: transgene insertion 2, Edward H Leiter
Chromosome: 15
Strain of origin: NOD/ShiLt
Expressed genes: GAD2,glutamate decarboxylase 2,human
Molecular note: The transgene comprises the cDNA sequence encoding human glutamic acid decarboxylase 2 under control of a modified rat insulin 2 promoter composed of 9.5 kb of genomic DNA from upstream of the transcription initiation site fused to the first intron of Ins2. Densitrometric Southern blot analysis indicates presence of 4-5 copies of the transgene. FISH analysis and pseudo-Giemsa metaphase spread analysis showed integration to have occurred near the centromere of Chr 15. Expression in the pancreatic islets of transgenic mRNA has been demonstrated by reverse transcription followed by PCR (RT-PCR), and of GAD2 protein by western blot analysis.