B6;129S4-Gt(ROSA)26Sor^{tm3(CAG-tdTomato,-EGFP*)Zjh}/J

Stock number: 028582
Product name: IS reporter
Research areas: Neurobiology Research, Research Tools

Description

These IS reporter mice harbor a targeted mutation of the Gt(ROSA)26Sor locus with a loxP-flanked STOP cassette and a frt-flanked tdTomato sequence preventing transcription of a CAG promoter-driven enhanced green fluorescent protein (EGFP). tdTomato is expressed following Cre-mediated recombination. EGFP is only expressed following Cre-mediated and Flp-mediated recombination. This strain may be useful as an intersectional reporter for cre and FLP expression, or as a subtraction reporter for cre expression alone.

Detailed description

IS intersectional and subtraction reporter mice homozygous for this Rosa-CAG-LSL-Frt-tdTomato-Frt-EGFP conditional allele are viable and fertile. A loxP-flanked STOP cassette and a frt-flanked tdTomato cassette prevent transcription of the downstream EGFP sequence. Because this CAG promoter driven reporter construct was targeted for insertion into the Gt(ROSA)26Sor locus, tdTomato expression is determined by which tissue(s) express Cre recombinase. When bred to mice that express Cre recombinase, the resulting offspring will have the loxP-flanked STOP cassette deleted in the cre-expressing tissue(s). After cre excision, expression of EGFP is restricted by the frt-flanked tdTomato sequence. When bred to mice that express Flp recombinase, the resulting offspring will express EGFP only in cells that express Flp and previously expressed cre (intersectional), while still retaining tdTomato expression in cre-expressing tissue(s) (subtraction).

IS2 mice are distributed as B6;129S4-Gt(ROSA)26Sor^{tm7(CAG-dTomato,-EGFP)Zjh}/J (Stock No. 036760), IS2 mice carry a dTomato (dimer) reporter rather than the tdTomato (tandem dimer) reporter carried by this strain.

Development

The IS targeting vector was designed with (from 5' to 3') a CMV-IE enhancer/chicken beta-actin/rabbit beta-globin hybrid promoter (CAG), a loxP-flanked STOP cassette, a frt-flanked tdTomato sequence (tdTomato is a non-oligomerizing DsRed variant with a 12 residue linker fusing two copies of the protein (tandem dimer)), three copies of green fluorescent protein, and a Neo-polyA cassette. The three GFP sequences include emerald, TagGFP (Aequorea macrodactyla GFP), and hrGFP (Humanized Renilla reniformis GFP) variants. This entire construct was inserted between exons 1 and 2 of the Gt(ROSA)26Sor locus via electroporation of (C57BL/6 x 129S4/SvJae)F1-derived V6.5 embryonic stem (ES) cells. Correctly targeted ES cells were selected and chimeric males were bred to C57BL/6J females and offspring were subsequently bred together to create a homozygous colony of IS reporter mice. Upon arrival at The Jackson Laboratory, sperm was cryopreserved. To establish our live colony, an aliquot of frozen sperm was used to fertilize C57BL/6J oocytes (Stock No. 000664).

Allele

Symbol: Gt(ROSA)26Sor^{tm3(CAG-tdTomato,-EGFP*)Zjh}
Name: targeted mutation 3, Z Josh Huang
MGI accession ID: MGI:5700416
Generation method: Targeted
Attributes: Conditional ready (e.g. floxed); Reporter
Synonyms: IS
Marker symbol: Gt(ROSA)26Sor
Marker name: gene trap ROSA 26, Philippe Soriano
Marker synonyms: beta geo; Gtrgeo26; Gtrosa26; R26; ROSA26; SETD5-AS1; Thumpd3as1
Chromosome: 6
Strain of origin: (C57BL/6 x 129S4/SvJae)F1
Expressed genes: RFP,Red Fluorescent Protein,coral; GFP,Green Fluorescent Protein,
Site of expression: tdTomato is expressed following Cre-mediated recombination. EGFP is only expressed following Cre-mediated and Flp-mediated recombination.
Molecular note: The targeting vector is designed with (from 5' to 3') a CMV-IE enhancer/chicken beta-actin/rabbit beta-globin hybrid promoter (CAG), a loxP-flanked STOP cassette, an FRT-flanked tdTomato sequence (tdTomato is a non-oligomerizing DsRed variant with a 12 residue linker fusing two copies of the protein (tandem dimer)), three copies of green fluorescent protein, and a Neo-polyA cassette. The three GFP sequences include emerald, TagGFP (Aequorea macrodactyla GFP), and hrGFP (Humanized Renilla reniformis GFP) variants. This entire construct was inserted between exons 1 and 2 of the Gt(ROSA)26Sor locus.