B6;129S-Ppp3r1^tm2Grc/J

Stock number: 017692
Product name: Cnb1flox
Research areas: Cell Biology Research, Research Tools

Description

This strain carries a floxed allele of the Ppp3r1 gene. Cre excision disrupts calcineurin enzymatic activity in non-germline cell types. These mice have been useful in studies of T cell development/selection.

Detailed description

LoxP sites flank exons 3-5 of the Calcineurin β1 (Ppp3r1, protein phosphatase 3, regulatory subunit B, alpha isoform (calcineurin B, type I)) gene in these floxed mutant mice. When bred to Cre-recombinase mice, excision of the floxed exons can be directed in a tissue/cell-specific manner in the resulting offspring. Disruption of the calcineurin β1 subunit results in a lack of calcineurin enzymatic activity in non-germline cell types. Ppp3r1 is a Ca²⁺-binding regulatory subunit of heterodimeric calcineurin, a Ca²⁺- and calmodulin-dependent serine/threonine protein phosphatase involved in a number of cellular processes and calcium-dependent signaling pathways.

When crossed with Lck-cre mice to specifically block calcineurin expression in thymocytes, it was shown that calcineurin β1 is essential for positive but not negative selection during thymocyte development.

When bred to a strain expressing Cre recombinase in endothelial cells (see Stock No. 008863 for example), this mutant mouse strain may be useful in studies of angiogenesis.

Development

Exons 3-5 of the targeted gene were flanked by loxP sites and an FRT-flanked neomycin cassette was introduced to intron 3 using TC1 129S6/SvEvTac-derived embryonic stem (ES) cells. Transient transfection with a FLP-expressing vector excised the neomycin cassette. This strain was backcrossed to 129S1/SvImJ and maintained on a mixed C57BL/6-129S genetic background by the donating lab.

Allele

Symbol: Ppp3r1^tm2Grc
Name: targeted mutation 2, Gerald R Crabtree
MGI accession ID: MGI:3044022
Generation method: Targeted
Attributes: Conditional ready (e.g. floxed); No functional change
Marker symbol: Ppp3r1
Marker name: protein phosphatase 3, regulatory subunit B, alpha isoform (calcineurin B, type I)
Chromosome: 11
Strain of origin: 129S6/SvEvTac
Molecular note: Exons 3 through 5 were flanked by single loxP sites. A single frt site remained in intron 3 following FLP-mediated excition of an frt-flanked neo cassette.