These floxed mutant mice possess loxP sites flanking exons 2 through 4 of the Rspo3 gene. This strain may be useful for generating conditional mutations in applications related to the activation of the Wnt/beta-catenin signaling pathway and regulation of development.
John Cobb, University of Calgary
R-spondin is an activator of the Wnt/beta-catnenin signaling pathway and a ligand for LGR (leucine-rich G protein-coupled) receptors. These mice possess loxP sites on either side of exons 2 through 4 of the targeted Rspo3 gene, which encode the furin-like and TSR-1 domains. Mice that are homozygous for this allele are viable and fertile. When these mutant mice are bred to mice that express Cre recombinase, resulting offspring will have exons 2 through 4 deleted in the cre-expressing tissues.
When bred to a strain with Cre recombinase expression in developing limb bud (see Stock No. 005584 for example), this mutant mouse strain may be useful in studies of limb development.
A FRT site flanked targeting vector containing PGK-Neo selection cassette was utilized in the construction of this mutant. This selection cassette and a 5’ loxP site was inserted downstream of exon 4 of the targeted gene, and another loxP site was inserted upstream of exon 2. This construct was electroporated into (129S6/SvEvTac x C57BL/6NCr)F1 derived G4 embryonic stem (ES) cells. Chimeric mice were generated by aggregating correctly targeted ES cells with CD-1 morula-stage embryos. The resulting male chimeric animals were crossed to CD-1 females. The mice were then crossed to transgenic mice (on the B6;SJL genetic background) expressing FLPe recombinase under the control of the human ACTB promoter (Stock No. 003800). Mice that retained the loxP site flanked exons 2-4 were then bred to remove the FLP recombinase transgene. Heterozygotes were crossed to generate homozygotes.
Upon arrival at The Jackson Laboratory, the mice were crossed to C57BL/6J (Stock No. 000664) at least once to establish the colony.
|Allele Name||targeted mutation 1.1, John Cobb|
|Allele Type||Targeted (Conditional ready (e.g. floxed), No functional change)|
|Gene Symbol and Name||Rspo3, R-spondin 3|
|Strain of Origin||(129S6/SvEvTac x C57BL/6NCrl)F1|
|Molecular Note||A loxP site was inserted upstream of exon 2. An FRT-flanked neo cassette with a 3' loxP site was inserted downstream of exon 4. Flp-mediated recombination removed the neo cassette and left exons 2 through 4 floxed.|
When maintaining a live colony, these mice can be bred as homozygotes.
When using the Rspo3F mouse strain in a publication, please cite the originating article(s) and include JAX stock #027313 in your Materials and Methods section.