B6;129-Gt(ROSA)26Sor^{tm1(CAG-Mir182)Dgk}/J

Stock number: 028611
Product name: LSL-miR-182
Research areas: Cell Biology Research

Description

LSL-miR-182 mice harbor a targeted mutation of the Gt(ROSA)26Sor locus with a loxP-flanked STOP cassette preventing transcription of a CAG promoter-driven microRNA-182 cDNA. These mice are useful for studying tumor metastasis in the lungs.

Detailed description

LSL-miR-182 mice homozygous for this Rosa-CAG-LSL-miR-182 conditional allele are viable and fertile. A loxP-flanked STOP cassette prevents transcription of the downstream miR-182 sequence. Because this CAG promoter driven reporter construct was targeted for insertion into the Gt(ROSA)26Sor locus, miR-182 over-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). miR-182 is a microRNA markedly overexpressed in some tumors that metastasize to the lungs.

When bred to KPY mice ((mix of two floxed mice: LSL-K-ras^G12D (Stock No. 008179) and p53^LoxP (Stock No. 008462) with an additional LSL-YFP allele (Stock No. 006148)), mice overexpressing miR-182 show an increased rate of lung metastasis from 40% in KPY control mice to 75% in experimental mice. Also, circulating tumor cells increased.

Development

A targeting vector was designed by Dr David Kirsch (Duke University) with (from 5' to 3') a CMV-IE enhancer/chicken beta-actin/rabbit beta-globin hybrid promoter (CAG), a frt site, a loxP-flanked STOP cassette (with stop codons in all 3 reading frames and a triple polyA signal), miR-182 sequence, a woodchuck hepatitis virus post-transcriptional regulatory element (WPRE; to enhance the mRNA transcript stability), a polyA signal, and an attB/attP-flanked PGK-frt-Neo-polyA cassette. This entire construct was inserted between exons 1 and 2 of the Gt(ROSA)26Sor locus via electroporation of 129Sv-derived embryonic stem (ES) cells. Correctly targeted ES cells were injected into C57BL/6 blastocysts and resulting chimeric mice were bred with C57BL/6 females. The resulting LSL-miR-182 mice were maintained on a mixed background. Upon arrival, 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^{tm1(CAG-Mir182)Dgk}
Name: targeted mutation 1, David Kirsch
MGI accession ID: MGI:5702434
Generation method: Targeted
Attributes: Conditional ready (e.g. floxed); Inserted expressed sequence
Marker symbol: Gt(ROSA)26Sor
Marker name: gene trap ROSA 26, Philippe Soriano
Chromosome: 6
Strain of origin: 129/Sv
Expressed genes: Mir182,microRNA 182,mouse, laboratory
Site of expression: Mir182 is expressed in cre-expressing tissues after breeding with a strain carrying cre recombinase.
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), an FRT site, a loxP-flanked STOP cassette (with stop codons in all 3 reading frames and a triple polyA signal), miR-182 sequence, a woodchuck hepatitis virus post-transcriptional regulatory element (WPRE; to enhance the mRNA transcript stability), a polyA signal, and an attB/attP-flanked PGK-FRT-Neo-polyA cassette. This entire construct was inserted between exons 1 and 2 of the Gt(ROSA)26Sor locus.