STOCK Gt(ROSA)26Sor^{tm1.2(CAG-EGFP)Fsh}/Mmjax

Stock number: 010812
Product name: RCE:FRT
Research areas: Neurobiology Research, Research Tools

Description

Removal of this mouse colony is imminent. If live mice are needed for your studies, it is advised that they be ordered immediately. After removal, the mice will be available from a cryorecovery.

These RCE:FRT mice harbor the R26R CAG-boosted EGFP (RCE) reporter allele with a FRT-flanked STOP cassette upstream of the enhanced green fluorescent protein (EGFP) gene. After removal of the FRT-flanked STOP cassette by Flp-mediated recombination, EGFP reporter expression is directed to the cells/tissues dependent upon expression of the promoter driving FLP recombinase.

Detailed description

Mice homozygous for the R26R CAG-boosted EGFP (RCE) reporter allele harboring an FRT-flanked STOP cassette (RCE:FRT) are viable and fertile. Under control of the endogenous Gt(ROSA)26Sor promoter/enhancer regions and the CMV-IE enhancer/chicken beta-actin/rabbit beta-globin (CAG) hybrid promoter, widespread expression of enhanced green fluorescent protein (EGFP) is prevented by the upstream FRT-flanked STOP cassette. After removal of the FRT-flanked STOP cassette by Flp-mediated recombination, EGFP reporter expression is directed to the cells/tissues dependent upon the expression pattern of the promoter driving FLP recombinase.

Development

The R26R CAG-boosted EGFP (RCE) reporter targeting vector was designed with (from 5' to 3') the CMV-IE enhancer/chicken beta-actin/rabbit beta-globin hybrid promoter (CAG; from the pCAGGS vector), a splice acceptor site, a loxP-flanked transcriptional STOP cassette (PGK-Neo-polyA and 3x-polyA), an FRT-flanked modified pBS302 STOP cassette, an enhanced green fluorescent protein (EGFP) sequence, and two AttP-polyA sequences. This entire construct was inserted into the first exon of the Gt(ROSA)26Sor locus via electroporation into 129S6/SvEvTac-derived W4 embryonic stem (ES) cells. Correctly targeted ES cells were injected into recipient blastocysts, and chimeric mice were bred with C57BL/6 mice to generate the RCE:dual colony. RCE:dual mice were then bred with a germline Cre-expressing strain (unspecified genetic background) to delete the loxP-flanked transcriptional STOP cassette. The resulting RCE:FRT offspring were mated with outbred Swiss Webster mice for many generations (selectively removing the Cre-expressing transgene), and subsequently maintained as homozygotes prior to arrival at The Jackson Laboratory. Upon arrival, mutant mice were bred to C57BL/6J inbred mice for at least one generation to establish the RCE:FRT colony.

Allele

Symbol: Gt(ROSA)26Sor^{tm1.2(CAG-EGFP)Fsh}
Name: targeted mutation 1.2, Gordon Fishell
MGI accession ID: MGI:4420764
Generation method: Targeted
Attributes: Conditional ready (e.g. floxed); Reporter
Marker symbol: Gt(ROSA)26Sor
Marker name: gene trap ROSA 26, Philippe Soriano
Chromosome: 6
Strain of origin: 129S6/SvEvTac
Site of expression: EGFP will be expressed in cells where promoters driving Flp recombinase are expressed.
Molecular note: Cre mediated recombination removes the loxP flanked STOP cassette from Gt(ROSA)26Sor^{tm1(CAG-EGFP)Fsh}. After removal of the FRT-flanked STOP cassette by Flp-mediated recombination, EGFP reporter expression is directed to the cells/tissues dependent upon the expression pattern of the promoter driving FLP recombinase.