B6(Cg)-Ins1^{tm1.1(cre)Thor}/J

Stock number: 026801
Product name: Ins1^cre
Research areas: Diabetes and Obesity Research, Endocrine Deficiency Research, Research Tools

Description

Ins1^cre mice express Cre recombinase in insulin-producing beta cells of pancreas starting at birth.

Detailed description

Ins1^cre mice express Cre recombinase 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, 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 Cre recombinase gene at the initiation codon of the Ins1 (Insulin I) gene with followed by a frt-flanked neomycin resistance (neo) cassette, replacing the Ins1 coding sequence. 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^cre mice were backcrossed for at least 5 generations to C57BL/6J mice by the donating lab (see SNP note below). 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.

In 2019 a 48 SNP (single nucleotide polymorphism) panel analysis, with 43 markers covering all 19 chromosomes and the X chromosome, as well as 5 markers that distinguish between the C57BL/6J and C57BL/6N substrains, was performed on the rederived living colony at The Jackson Laboratory Repository. One of the 43 markers throughout the genome was segregating with an unknown contributor, while 1 of 5 markers (on chromosome 19) that determine C57BL/6J from C57BL/6N were found to be segregating with C57BL/6NJ. These data suggest the mice sent to The Jackson Laboratory Repository were on a mixed C57BL/6J ; C57BL/6N genetic background.

Allele

Symbol: Ins1^{tm1.1(cre)Thor}
Name: targeted mutation 1.1, Bernard Thorens
MGI accession ID: MGI:5614359
Generation method: Targeted
Attributes: Recombinase-expressing; Null/Knockout
Marker symbol: Ins1
Marker name: insulin I
Chromosome: 19
Strain of origin: C57BL/6J
Expressed genes: cre,cre recombinase,bacteriophage P1
Site of expression: Cre recombinase is expressed in insulin-producing beta cells of pancreas.
Molecular note: A targeting construct was designed to insert a cre recombinase gene 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.