B6(Cg)-Ins1^{tm2.1(cre/ERT2)Thor}/J

Stock number: 026802
Research areas: Diabetes and Obesity Research, Endocrine Deficiency Research, Research Tools

Description

Ins1^CreERT2 mice express Cre-ER^T2 in insulin-producing beta cells of pancreas starting at birth. They are useful for applications requiring tamoxifen-induced deletion of floxed sequences in beta cells.

Detailed description

Ins1^CreERT2 mice express a creER^T2 fusion gene from the start codon of the Ins1 (Insulin I) gene, replacing the entire coding region. Insulin is a hormone produced by beta cells in the pancreas. It regulates the metabolism of carbohydrates and fats by promoting the absorption of glucose from the blood to skeletal muscles and fat tissue and by causing fat to be stored rather than used for energy. Homozygous mice are viable and fertile. When these mice are bred with mice containing loxP-flanked sequence, tamoxifen-inducible, Cre-mediated recombination will result in deletion of the floxed sequences in the beta cells of the offspring. The donating investigator reports that no cre expression is seen in the central nervous system.

Development

A targeting construct was designed to insert a creER^T2 fusion gene (a Cre recombinase fused to a human estrogen receptor ligand binding domain) at the initiation codon of the Ins1 (Insulin I) gene with followed by polyadenylation sequence and a frt-flanked neomycin resistance (neo) cassette. This construct was electroporated into C57BL/6-derived embryonic stem (ES) cells. Correctly targeted ES cells were injected into blastocysts and the resulting chimeric mice were bred to C57BL/6J mice. Mice were bred to flp transgenic mice, on a C57BL/6J background, to remove the neo cassette, and resulting mice were crossed to remove the flp-expressing transgene. Ins1 ^CreERT2 mice were backcrossed for at least 9 generations to C57BL/6J mice. Upon arrival at The Jackson Laboratory, mice were bred to C57BL/6J inbred mice (Stock No. 000664) for at least one generation to establish the colony.

Allele

Symbol: Ins1^{tm2.1(cre/ERT2)Thor}
Name: targeted mutation 2.1, Bernard Thorens
MGI accession ID: MGI:5614361
Generation method: Targeted
Attributes: Recombinase-expressing; Inducible; Null/Knockout
Marker symbol: Ins1
Marker name: insulin I
Chromosome: 19
Strain of origin: C57BL/6J
Expressed genes: cre/ERT2,Cre recombinase and estrogen receptor 1 (human) fusion gene,
Site of expression: cre/ERT2 is expressed in insulin-producing beta cells of pancreas.
Molecular note: A targeting construct was designed to insert a cre recombinase gene fused with a modified estrogen receptor gene (cre/ERT2) at the initiation codon of the gene with followed by a FRT-flanked neomycin resistance (neo) cassette, replacing the coding sequence. Flp-mediated recombination removed the FRT-flanked neo cassette.