B6.129S7-Gja1^tm1Dlg/J

Stock number: 008039
Product name: floxed Cx43
Research areas: Cardiovascular Research, Research Tools

Description

Cx43^flox mice may be useful in generating conditional mutations for studying the role of connexin and gap junctions in various tissues and systems, including the cardiovascular system.

Detailed description

Mice homozygous for this Gja1^tm1Dlg (also known as Cx43^flox) conditional allele are viable and fertile, with loxP sites flanking exon 2 of the targeted gene. Presence of the loxP sites has no reported affect on expression of the targeted gene. When bred to mice that express Cre recombinase, the resulting offspring will have exon 2 deleted in the cre-expressing tissue(s). These Gja1^tm1Dlg mutant mice may be useful in generating conditional mutations for studying the role of connexin and gap junctions in various tissues and systems, including the cardiovascular system.

Development

A targeting vector was designed to place a loxP site just upstream of, and a loxP-flanked neo/TK cassette just downstream of exon 2 of the targeted gene. This construct was electroporated into 129S7/SvEvBrd-derived AB2.2 embryonic stem (ES) cells. Correctly targeted ES cells were then transiently transfected with a Cre expressing plasmid. The resulting ES cells with the selection cassette removed and a single loxP site remaining on each side of exon 2 (called "type II deletion: conditional mutation" in the primary publication) were injected into C57BL/6 blastocysts. Chimeric mice were bred to C57BL/6 mice to generate Cx43^flox mutant mice. These mice were backcrossed to C57BL/6NTac using a speed congenic approach and determined to be congenic on this background prior to arrival at The Jackson Laboratory.

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. Three of the 5 markers that determine C57BL/6J from C57BL/6N were found to be segregating, on Chromosomes 10, 15, and the rd8 recessive mutation associated with retinal degeneration on Chromosome 1 within the Crb1 locus. These data suggest the mice sent to The Jackson Laboratory Repository were on a mixed C57BL/6N;C57BL/6J genetic background.

Allele

Symbol: Gja1^tm1Dlg
Name: targeted mutation 1, Brian R Duling
MGI accession ID: MGI:2159007
Generation method: Targeted
Attributes: Conditional ready (e.g. floxed); No functional change
Synonyms: Cx43^fl
Marker symbol: Gja1
Marker name: gap junction protein, alpha 1
Chromosome: 10
Strain of origin: 129S7/SvEvBrd-Hprt^b-m2
Molecular note: LoxP sites were inserted flanking exon 2. A neomycin selection cassette and thymidine kinase gene that were also inserted 3' to the loxP sites were removed by transient cre recombinase expression in ES cells prior to the production of chimeric mice. Western blot and immunohistochemistry analysis on homozygous mice confirmed that there were no detectable changes in the expression of the encoded protein.