These floxed mutant mice possess loxP sites flanking exon 2 of the Stim1 gene. This strain may be useful for generating conditional mutations in applications related to the regulation of store-operated Ca2+ entry and Ca2+ homeostasis.
Anjana Rao, La Jolla Institute for Allergy and Immunology
The stromal interaction molecule 1 (Stim1) gene encodes a calcium Ca2+ sensing transmembrane protein located in the endoplasmic reticulum (ER) that becomes activated upon decrease of ER luminal Ca2+. The activated STIM1 protein then translocates into ER plasma membrane junctions where it activates plasma membrane Orai Ca2+ channels.
These mice possess loxP sites on either side of the Stim1 exon 2. 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 exon 2 deleted in the cre-expressing tissues. During backcrossing, the Y chromosome may not have been fixed to the C57BL/6 (??) genetic background.
When bred to a strain with Cre recombinase expression in T cells (see Stock No. 017336 for example), this mutant mouse strain may be useful in studies of store-operated Ca2+ entry.
A FRT site flanked targeting vector containing a NEO cassette with an upstream loxP site was utilized in the construction of this mutant. This selection cassette was inserted upstream of exon 2 of the targeted gene, and another loxP site was inserted downstream of exon 2. This construct was electroporated into C57BL/6 derived Bruce 4 embryonic stem (ES) cells. Correctly targeted ES cells were injected into blastocysts. The resulting chimeric animals were crossed to mice (on the C57BL/6 genetic background) expressing Flpe recombinase under the direction of the human ACTB promoter (see Stock No. 005703 for example).
Mice that retained the loxP site flanked exon 2 were then backcrossed to C57BL/6 for 2 generations. The mice no longer carry the Flpe recombinase transgene. During backcrossing, the Y chromosome may not have been fixed to the C57BL/6 genetic background. 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, Anjana Rao|
|Allele Type||Targeted (Conditional ready (e.g. floxed), No functional change)|
|Gene Symbol and Name||Stim1, stromal interaction molecule 1|
|Strain of Origin||B6.Cg-Thy1a|
|Molecular Note||An frt-flanked neo cassette with a 5' loxP site was inserted upstream of exon 2 and an additional loxP site was inserted downstream of exon 2. Germ-line, flp-mediated recombination was used to remove the neo cassette.|
When maintaining a live colony, these mice can be bred as homozygotes.
When using the Stim1fl/fl mouse strain in a publication, please cite the originating article(s) and include JAX stock #023350 in your Materials and Methods section.