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

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

Description

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.