B6.129S4-Gt(ROSA)26Sor^tm1Sor/J

Stock number: 003474
Product name: R26R
Research areas: Neurobiology Research, Research Tools

Description

These Gt(ROSA)26Sor^tm1Sor targeted mutant mice carry a loxP flanked neo cassette upstream of a β-galactosidase (lacZ) sequence. Removal of the neo cassette by cre recombination results in lacZ expression in cre-expressing tissues of the offspring. These mutant mice may be used as a Cre-reporter strain to test the tissue/cellular expression pattern of cre expressing mice.

Detailed description

Homozygous mice are viable and fertile, with a loxP-flanked DNA STOP sequence preventing expression of the downstream lacZ gene. When crossed with a cre transgenic strain, the STOP sequence is removed and lacZ is expressed in cells/tissues where cre is expressed. These mutant mice may be used as a Cre-reporter strain; to test the tissue/cellular expression pattern of cre transgenic mice.

Development

The R26R targeting construct was created by subcloning the pROSA26-1 vector, and inserting a splice acceptor sequence (identical to the one used in the original gene trap allele), a loxP-flanked STOP sequence (containing a neo cassette and triple polyadenylation (STOP) sequence), a lacZ gene, and a polyadenylation sequence at a unique site approximately 300-bp 5' of the original gene trap integration site. Transcriptional read-through is prevented with the use of a triple polyadenylation (STOP) sequence at the 3' end of the neo expression cassette. The construct was electroporated into 129S4/SvJaeSor derived AK7 embryonic stem (ES) cells. This strain arose on a B6;129 background and was backcrossed to C57BL/6J utilizing a marker-assisted protocol.

Allele

Symbol: Gt(ROSA)26Sor^tm1Sor
Name: targeted mutation 1, Philippe Soriano
MGI accession ID: MGI:1861932
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: 129S4/SvJaeSor
Expressed genes: lacZ,beta-galactosidase,E. coli
Site of expression: when crossed to a Cre recombinase-expressing strain, lacZ expression is observed in the cre-expressing tissues
Molecular note: A targeting vector was designed from the original gene trap strain, ROSA beta-geo26, to include a splice acceptor sequence (SA), a neo expression cassette flanked by loxP sites, a lacZ gene, and a polyadenylation (bpA) sequence inserted at a unique Xba1 site approximately 300-bp 5' of the original gene-trap integration site. In addition, a triple polyadenylation sequence was added to the 3' end of the neo expression cassette to prevent transcriptional read-through. Presence of the floxed neo cassette prevents lacZ expression. When crossed with a cre transgenic strain, lacZ is expressed in all cells/tissue where Cre is expressed.