B6(SJL)-Crb3^tm1.1Lprs/J

Stock number: 028841
Product name: Crb3^flox
Research areas: Developmental Biology Research, Internal/Organ Research, Research Tools

Description

Crb3^flox mice possess loxP sites flanking the start codon of the Crb3 gene, making this strain useful for studying the regulation of epithelial polarity and tight junctions.

Detailed description

Crb3^flox mice possess loxP sites flanking exon 2, including the start codon, of the crumbs family member 3 (Crb3) gene. CRB3 is essential for the formation and maintenance of epithelial polarity and plays an important role in regulating the morphogenesis of tight junctions. Mice that are homozygous for this allele are viable and fertile. When bred to mice that express tissue-specific Cre recombinase, resulting offspring will have exon 2 deleted in the cre-expressing tissues.

When bred to B6.C-Tg(CMV-cre)1Cgn/J mice (Stock No. 006054) with wide-spread expression of Cre recombinase, resulting Crb3^-/- offspring die soon after birth from respiratory distress. They also exhibit kidney cysts and defect in intestinal epithelium development.

Development

A targeting vector was designed by Dr. Patrick Laprise (University of Laval) to insert a loxP site upstream of exon 2, including the start codon, and a frt-flanked neomycin resistance (neo) cassette, followed by a second loxP site, downstream of exon 2 of the crumbs family member 3 (Crb3) gene. The construct was electroporated into C57BL/6N-derived embryonic stem (ES) cells. Correctly targeted ES cells were injected into BALB/c blastocysts and resulting chimeric mice were bred with B6.Cg-Tg(ACTFLPe)9205Dym/J mice (Stock No. 005703) to delete the neo cassette. Progeny were crossed to remove the Flp-expressing transgene, and resulting Crb3^flox mice were bred to C57BL/6J mice. Upon arrival at The Jackson Laboratory, cryopreserved sperm was used to fertilize C57BL/6J oocytes (Stock No. 000664).

Allele

Symbol: Crb3^tm1.1Lprs
Name: targeted mutation 1.1, Patrick Laprise
MGI accession ID: MGI:5749246
Generation method: Targeted
Attributes: Conditional ready (e.g. floxed)
Marker symbol: Crb3
Marker name: crumbs family member 3
Chromosome: 17
Strain of origin: C57BL/6
Molecular note: The targeting vector was designed to insert a loxP site upstream of exon 2, a loxP site downstream of exon 2, followed by an FRT-flanked neomycin resistance (neo) cassette, and a third loxP site. Exon 2 is the first coding exon of the gene. Flp-mediated recombination removed the FRT-flanked neo cassette leaving exon 2 floxed.