These RXRalpha floxed mutant mice may be useful in generating conditional mutations for studying liver regeneration, cardiac development, and hepatocellular carcinogenesis.
Yui-Jui Yvonne Wan, University of California, Davis Medical Center
These mice possess loxP sites on either side of exon 4 of the targeted gene. Mice that are homozygous for this allele are viable, fertile, normal in size and do not display any gross physical or behavioral abnormalities. When these mutant mice are bred to mice that express Cre recombinase, resulting offspring will have exon 4 deleted in the cre-expressing tissues.
When bred to a strain with Cre recombinase expression in liver (see Stock No. 003574 for example), this mutant mouse strain may be useful in studies of hepatocyte proliferation and liver regeneration.
When bred to a strain with Cre recombinase expression in myeloid cell lineages (see Stock No. 004781 for example), this mutant mouse strain may be useful in studies of glomerulonephritis, autoimmunity and systemic lupus erythematosus (SLE).
A loxP site flanked PGK-neo cassette was inserted downstream of exon 4 of the targeted gene, and another loxP site was inserted upstream of exon 4. This construct was electroporated into 129S4/SvJae derived J1 embryonic stem (ES) cells which were transiently transfected with a Cre recombinase plasmid to remove the selection cassette (RXRalpha allele or RXRalpha flox). ES cells in which Cre recombination resulted in exon 4 being flanked by loxP sites (the 2-lox allele) were injected into C57BL/6 blastocysts. The resulting mice were then crossed to transgenic mice on an unspecified genetic background that contained at least partial C57BL/6 genomic content. The donating investigator reported that these mice were then backcrossed to C57BL/6J for 10 generations (see SNP note below). Upon arrival at The Jackson Laboratory, the mice were crossed to C57BL/6J (Stock No. 000664) at least once to remove the transgene and establish the colony.
A 32 SNP (single nucleotide polymorphism) panel analysis, with 27 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 27 markers throughout the genome were found to be segregating for 129. One marker on Chromosome 9 is from an unknown source. These data suggest the mice sent to The Jackson Laboratory Repository were on a mixed genetic background.
|Allele Name||targeted mutation 1, Kenneth R Chien|
|Allele Type||Targeted (Conditional ready (e.g. floxed), No functional change)|
|Allele Synonym(s)||RXRalphafl; RXRalphafloxed; RXRalphaflox|
|Gene Symbol and Name||Rxra, retinoid X receptor alpha|
|Strain of Origin||129S4/SvJae|
|Molecular Note||A loxP site was introduced into intron 3 and a floxed PGK-neo-tk cassette was introduced into intron 4 via homologous recombination. The PGK-neo-tk cassette was subsequently removed in correctly targeted cells by the transient expression of cre recombinase, leaving behind loxP sites flanking exon 4.|
When maintaining a live colony, these mice can be bred as homozygotes.
When using the STOCK Rxratm1Krc/J mouse strain in a publication, please cite the originating article(s) and include JAX stock #013086 in your Materials and Methods section.