Cx43flox 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.
Brian R Duling, Univ. of Virginia School of Medicine
Mice homozygous for this Gja1tm1Dlg (also known as Cx43flox) 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 Gja1tm1Dlg 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.
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 Cx43flox 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 Name||targeted mutation 1, Brian R Duling|
|Allele Type||Targeted (Conditional ready (e.g. floxed), No functional change)|
|Gene Symbol and Name||Gja1, gap junction protein, alpha 1|
|Strain of Origin||129S7/SvEvBrd-Hprtb-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.|
|Mutations Made By|| |
Brian Duling, Univ. of Virginia School of Medicine
When maintaining a live colony, homozygous mice may be bred together.
When using the floxed Cx43 mouse strain in a publication, please cite the originating article(s) and include JAX stock #008039 in your Materials and Methods section.