STOCK Lrig1^{tm1.1(cre/ERT2)Rjc}/J

Stock number: 018418
Product name: Lrig1-CreERT2
Research areas: Cancer Research, Research Tools

Description

In this strain Cre-ERT2 is knocked into the translational start site of the Lrig1 (leucine-rich repeats and immunoglobulin-like domains 1) gene. This strain may be useful for mediating inducible cre recombination in Lrig1 expressing tissues, and for applications in lineage mapping proliferative and quiescent intestinal progenitor cells.

Detailed description

Lrig1 (leucine-rich repeats and immunoglobulin-like domains 1) encodes a transmembrane protein that negatively regulates ErbB receptors, Met and Ret, and is a marker for intestinal and skin progenitor cells. These Lrig1-CreERT2 mice carry a targeted mutation in which Cre-ERT2 is knocked into the endogenous ATG site of the Lrig1 gene. Although homozygotes are viable and fertile on the mixed B6;129 background, by 6 months of age homozygotes develop duodenal adenomas and some homozygous females exhibit impaired lactation. Homozygotes on the congenic C57BL/6 background exhibit an embryonic lethal phenotype. Heterozygotes are viable and fertile. These mice display robust inducible Cre recombination activity at a greater efficiency than that seen in Lgr5-EGFP-IRES-CreERT2 mice (Stock No. 008875). The Cre-ERT2 fusion protein is only active when it binds to the estrogen analog 4-hydroxytamoxifen (OHT). When these mice are bred with mice containing a loxP-flanked sequence, tamoxifen-inducible Cre-mediated recombination is expected to result in deletion of the floxed sequences in the Cre recombinase and Lrig1 expressing quiescent intestinal, gastric epithelium and skin progenitor cells of the offspring.

Development

A targeting vector designed by Dr. Robert J. Coffey (Vanderbilt University) containing sequence encoding Cre recombinase-estrogen receptor (Cre-ERT2) fusion protein, SV40 polyA signal, and an FRT-flanked PGK-neo cassette was inserted immediately after the endogenous ATG site of Lrig1. The construct was electroporated into 129S6/SvEvTac derived TL1 embryonic stem (ES) cells. Correctly targeted ES cells were injected into blastocysts. The resulting chimeric animals were crossed to B6.Cg-Tg(ACTFLPe)9205Dym/J (Stock No. 005703) mice to remove the FRT site flanked NEO cassette. Upon arrival at The Jackson Laboratory, the mice were crossed to C57BL/6J (Stock No. 000664) at least once to establish the colony.

Allele

Symbol: Lrig1^{tm1.1(cre/ERT2)Rjc}
Name: targeted mutation 1.1, Robert J Coffey
MGI accession ID: MGI:4947937
Generation method: Targeted
Attributes: Recombinase-expressing; Inducible
Marker symbol: Lrig1
Marker name: leucine-rich repeats and immunoglobulin-like domains 1
Chromosome: 6
Strain of origin: 129S6/SvEvTac
Expressed genes: cre/ERT2,Cre recombinase and estrogen receptor 1 (human) fusion gene,
Site of expression: Intestinal colonic stem cells located at the crypt base.
Molecular note: The targeting vector used for homologous recombination was generated by BAC recombineering. A tamoxifen-inducible cre (cre/ERT2) sequence, SV40 polyA signal, and an Frt-flanked PGK-neo cassette were targeted to the endogenous ATG site of Lrig1. Chimeras were crossed with Flpe-expressing animals to remove the neo from the germline.