B6(Cg)-Gt(ROSA)26Sor^{tm1(CAG-taulacZ)Bene}/J

Stock number: 010633
Research areas: Neurobiology Research, Research Tools

Description

These mice harbor a targeted mutation of the Gt(ROSA)26Sor locus with a loxP-flanked neo cassette preventing transcription of a CAG promoter-driven tau- beta galactosidase (tauLacZ) gene, and may be useful as a cre reporter strain. Beta galactosidase is expressed following cre-mediated recombination.

Detailed description

Mice that are homozygous for the targeted mutation are viable, fertile and normal in size. A loxP-flanked neo cassette prevents transcription of the downstream tau- beta galactosidase (tauLacZ) gene. When bred to mice that express Cre recombinase, the resulting offspring will have the neo cassette deleted in the cre-expressing tissue(s); resulting in expression of taulacZ. Upon histochemical staining with X-gal, the tau beta galactosidase activity is revealed as an intense blue precipitate found in the entire cell, regardless of cell type. When tested with an olfactory sensory neuron specific cre-expressing strain, expression of lacZ labels axon projections. This mutant mouse strain may be useful as a cre reporter.

Development

A targeting vector containing a CAG promoter, a loxP flanked neomycin resistance gene followed by a tau-lacZ fusion gene and a polyadenylation sequence (CAG-loxP-neo-pA-loxP-tauLacZ-pA) was inserted in reverse orientation into the Gt(ROSA)26 locus. The construct was electroporated into B6(Cg)-Tyr^c-2J derived CY2.4 embryonic stem (ES) cells, correctly targeted ES cells were injected into recipient C57BL/6 blastocysts and chimeric males were bred with B6(Cg)-Tyr^c-2J females to generate the first generation. The resulting mice were crossed to C57BL/6J mice and bred to homozygosity. Upon arrival, mice were bred to C57BL/6J for at least 1 generation to establish the colony.

Allele

Symbol: Gt(ROSA)26Sor^{tm1(CAG-taulacZ)Bene}
Name: targeted mutation 1, Robert Benezra
MGI accession ID: MGI:4366911
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: B6(Cg)-Tyr^c-2J
Expressed genes: lacZ,beta-galactosidase,E. coli; neo,neomycin resistance,bacterial
Site of expression: A loxP-flanked neo cassette prevents transcription of tauLacZ. When bred to mice that express Cre recombinase, tissue-specific expression of taulacZ is enabled.
Molecular note: A genetic construct that reports cre recombinase activity with tauLacZ reporter gene was inserted in reverse orientation into the Gt(ROSA)26Sor safe harbor locus. The reporter construct included a CAG promoter, a loxP flanked stop cassette composed of neomycin resistance gene and multiple polyadenylation sequences, a tauLacZ reporter gene, and a polyadenylation sequence (pCAG-loxP-pEM7-Neo*-bGHpA-3xSV40pA-loxP-tauLacZ-bGHpA). The construct was electroporated into B6(Cg)-Tyrc-2J derived CY2.4 embryonic stem cells. Southern blot positive embryonic stem cell clones were injected into recipient C57BL/6J blastocysts. Positive male chimeras were bred with B6(Cg)-Tyrc-2J females. Albino pups were genotyped by PCR, then bred to B6J mice.