B6.Cg-Gt(ROSA)26Sor^{tm16(CAG-RRAS2,-EGFP)Geno}/J

Stock number: 040817
Product name: Rosa26-RRAS2^fl
Research areas: Cancer Research, Cell Biology Research, Immunology, Inflammation and Autoimmunity Research, Research Tools

Description

Rosa26-RRAS2^fl mice harbor a Cre-inducible human wildtype RRAS2 sequence, and an EGFP, knocked-into the Gt(ROSA)26Sor locus. These mice may be useful when studying over-expression of R-RAS2 in cancers, such as Chronic lymphocytic leukemia (CLL).

Detailed description

Rras2 (related RAS viral (r-ras) oncogene 2) is a member of the Ras-subfamily of small guanosine-5'-triphosphate-binding proteins. It is involved with B-and T-cell development and with providing homeostatic signals to support mature B- and T-cell numbers. Mutations in this gene, as well as R-RAS2 overexpression, have been implicated in several cancers. These Rosa26-RRAS2^fl knock-in (KI) mice express Cre-inducible HA-tagged human wildtype RRAS2, as well as an enhanced green fluorescent protein (EGFP) from the GT(ROSA)26Sor locus.

Homozygous mice are viable and fertile, with no overt phenotype. When bred to mice that express tissue-specific Cre recombinase, resulting offspring will overexpress human R-RAS2 in cre-expressing tissues. EGFP fluorescence is detectable by flow cytometry and immunostaining. The donating laboratory bred these Rosa26-RRAS2^fl KI mice to a Sox2-Cre mouse line to generate mice that ubiquitously overexpress wildtype human R-RAS2 protein. Resulting RRAS2^fl/flxSox2-Cre progeny had significantly enlarged spleens compared to controls and developed chronic lymphocytic leukemia (CLL). The female breeders also develop a faster-growing ductal breast adenocarcinoma characterized as the triple-negative type. These mice may be useful when studying over-expression of R-RAS2 in cancers, such as CLL and triple-negative breast cancer, as well as tracking RRAS2-overexpressing cells.

Development

The Rosa26-RRAS2^fl knock-in (KI) allele was generated by inserting the wildtype human related RAS viral (r-ras) oncogene 2 (RRAS2) with an HA-tag, followed by an enhanced green fluorescent protein (EGFP) into the GT(ROSA)26Sor locus (CTV plasmid, Addgene catalog# 15912). The final targeting construct consists of a CAG (CMV enhancer/chicken beta-actin) promoter, a loxP flanked STOP cassette (which includes a neomycin resistance gene), an HA-tagged human wildtype RRAS2 cDNA, an initial FRT-site followed by an internal ribosome entry site (IRES), an EGFP sequence, a second FRT-site and a polyA tail. The construct was electroporated into (129S6/SvEvTac x C57BL/6NCr)F1-derived G4 embryonic stem (ES) cells and correctly targeted ES cells were injected into recipient blastocysts. The chimeric mice were bred to C57BL/6J mice to confirm germline transmission. The resulting Rosa26-RRAS2^fl KI mice were maintained on a C57BL/6J background, for multiple generations, by the donating laboratory. Upon arrival, sperm was cryopreserved. To establish a live colony, an aliquot of frozen sperm was used to fertilize C57BL/6J oocytes (Stock No. 000664).

Allele

Symbol: Gt(ROSA)26Sor^{tm16(CAG-RRAS2,-EGFP)Geno}
Name: targeted mutation 16, Genoway
MGI accession ID: MGI:7660852
Generation method: Targeted
Attributes: Conditional ready (e.g. floxed); No functional change; Epitope tag
Synonyms: Rosa26-RRAS2^fl
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: (129S6/SvEvTac x C57BL/6NCrl)F1
Molecular note: The targeting construct inserted into the locus a CAG (CMV enhancer/chicken beta-actin) promoter, a loxP flanked STOP cassette (which includes a neomycin resistance gene), an HA-tagged human wildtype RRAS2 cDNA, an initial FRT-site followed by an internal ribosome entry site (IRES), an EGFP sequence, a second FRT-site and a polyA tail.