C57BL/6-Ucp1^{tm1.1(cre)Myna}/HmunJ

Stock number: 042239
Product name: UCP1-IRES-Cre
Research areas: Cardiovascular Research, Research Tools

Description

UCP1-IRES-Cre knock-in mice express Cre recombinase under the direction of the Ucp1 promoter in brown and white adipose tissues. These mice are useful when studying thermogenesis and energy metabolism.

Detailed description

UCP1-IRES-Cre knock-in mice have an IRES-cre cassette inserted immediately downstream of the stop codon in exon 6 of the uncoupling protein 1 (mitochondrial, proton carrier) (Ucp1) gene. The presence of IRES-cre cassette allows for expression of UCP1 and Cre. Ucp1 encodes a mitochondrial uncoupling protein localized to the mitochondrial inner membrane in brown and white adipose tissues where it plays a central role in thermogenesis and energy metabolism. When these mice are bred with mice containing loxP-flanked sequence, Cre-mediated recombination will result in deletion of the floxed sequences in the cre-expressing cells of the offspring. Homozygous mice are viable and fertile.

When bred to Ai14 tdTomato reporter mice (Stock No. 007914), Cre-mediated removal of the STOP cassette in the Ai14 mice results in tdTomato fluorescence in brown and white adipose tissue depots. The mice also exhibit limited ectopic activity in the hypothalamus and peripheral organs, as well as choroid plexus. The donating investigator reports that the ectopic Cre expression is substantially reduced when compared to that seen in Ucp1-cre transgenic mice (Stock No. 024670).

Development

A targeting construct was designed to insert an internal ribosome entry site fused to a cre sequence, followed by a loxP-flanked neomycin resistance (neo) cassette, immediately downstream of the stop codon in exon 6 of the uncoupling protein 1 (mitochondrial, proton carrier) (Ucp1) gene. This construct was electroporated into C57BL/6-derived embryonic stem (ES) cells. Correctly targeted ES cells were injected into blastocysts and the resulting chimeric UCP1-IRES-Cre mice were bred to C57BL/6J mice (Stock No. 000664). Subsequent self-excising Cre recombinase activity deleted the neo cassette. Mice were maintained by backcrossing to C57BL/6J mice by the donating laboratory. 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.

Allele

Symbol: Ucp1^{tm1.1(cre)Myna}
Name: targeted mutation 1, Randall L Mynatt
MGI accession ID: MGI:8472468
Generation method: Targeted
Attributes: Recombinase-expressing
Marker symbol: Ucp1
Marker name: uncoupling protein 1 (mitochondrial, proton carrier)
Marker synonyms: Slc25a7; Ucp; Ucpa; Uncp
Chromosome: 8
Strain of origin: C57BL/6
Molecular note: A targeting construct was designed to insert an internal ribosome entry site fused to a cre sequence, followed by a loxP-flanked neomycin resistance (neo) cassette, immediately downstream of the stop codon in exon 6 of the uncoupling protein 1 (mitochondrial, proton carrier) (Ucp1) gene. Subsequent self-excising Cre recombinase activity deleted the neo cassette.