B6.129(SJL)-Ins2^{tm1.1(cre)Wpiz}/ArvnJ

Stock number: 037540
Product name: Ins2-Cre
Research areas: Cardiovascular Research, Diabetes and Obesity Research, Metabolism Research, Research Tools

Description

Ins2-Cre knock-in mice express Cre recombinase under the direction of the Ins2 promoter in β cells of the pancreas.

Detailed description

Ins2-Cre knock-in mice have an IRES-Cre cassette inserted between the stop codon and 3' UTR of the 3rd exon of the insulin II (Ins2) gene. The presence of IRES-Cre cassette downstream of the stop codon allows for expression of INS2 and Cre. Ins2 encodes one of the two insulin genes in the mouse. Ins2 is a peptide hormone involved in the regulation of carbohydrate and lipid metabolism. When these mice are bred with mice containing loxP-flanked sequence, Cre-mediated recombination will result in deletion of the floxed sequences in the cre-expressing cells of the offspring. Heterozygous mice are viable and fertile, the donating investigator has not attempted to maintain a homozygous colony.

These mice display robust Cre expression and activity in pancreatic β cells without significant alterations in insulin expression. In the brain, Cre activity is mainly restricted to the choroid plexus, without significant recombination detected in the hippocampus or hypothalamus.

Of note, very low levels of Cre have been detected in the thymus, which could potentially alter T cell selection which may influence experimental outcomes.

Development

A targeting construct was designed to insert an internal ribosomal entry site (IRES) and a Cre recombinase with a polyadenylation signal, followed by an FRT-flanked neomycin resistance (neo) cassette, between the stop codon and 3′ UTR of the 3rd exon of insulin II (Ins2) gene. This construct was electroporated into 129/Sv-derived embryonic stem (ES) cells. Correctly targeted ES cells were injected into C57BL/6 blastocysts and the resulting chimeric Ins2-Cre mice were bred to ACTB:FLPe mice (see Stock No. 005703) to remove the neo cassette. Offspring were crossed to remove the Flpe expressing gene. Mice were further backcrossed to C57BL/6J mice (Stock No. 000664) for at least 4 generations by the donating laboratory. Upon arrival at The Jackson Laboratory, sperm was cryopreserved. To establish our live colony, an aliquot of frozen sperm was used to fertilize C57BL/6J oocytes.

Allele

Symbol: Ins2^{tm1.1(cre)Wpiz}
Name: targeted mutation 1.1, Weiping Zhang
MGI accession ID: MGI:6423077
Generation method: Targeted
Attributes: Recombinase-expressing
Marker symbol: Ins2
Marker name: insulin II
Chromosome: 7
Strain of origin: 129/Sv
Molecular note: An IRES-Cre-bpA DNA sequence and an frt-flanked neomycin selection cassette was inserted between the stop codon ad the 3'UTR in the third exon. The neomycin selection cassette was subsequently removed via FLP-mediated recombination in the germline.