The Brs3 gene encodes an orphan G protein-coupled receptor that is involved in the regulation of metabolism and is expressed in the CNS, gastrointestinal tract, and some tumors. These Brs3-2A-CreERT2 mice have tamoxifen-inducible Cre recombinase activity under the control of the endogenous elements of the Brs3 gene. 2A-CreERT2 sequence was inserted into exon 3, replacing the stop codon. Tamoxifen-inducible cre activity mimics the endogenous Brs3 gene expression pattern. This allele is a hypomorph. Male hemizygotes exhibit a small increase in body weight, fat mass and lean mass when fed a chow diet compared to wildtype controls. Homozygous female mice and hemizygous male mice (the gene is X-linked) are viable and fertile. This allele is subject to X-inactivation in females. When these Brs3-2A-CreERT2 mice are bred with mice containing a loxP-flanked sequence of interest, tamoxifen-inducible, Cre-mediated recombination will result in deletion of the flanked sequences in Brs3 expressing cells. When crossed to a fluorescent reporter strain, no fluorescent protein was detected without tamoxifen induction. The Donating Investigator reports that only hemizygous males were assessed for body mass and food intake, and heterozygous females do not exhibit any overt phenotype.The Cre-ERT2 fusion protein consists of Cre recombinase fused to a triple mutant form of the human estrogen receptor which does not bind its natural ligand (17&beta;-estradiol) at physiological concentrations but will bind the synthetic estrogen receptor ligands 4-hydroxytamoxifen (OHT or tamoxifen) and, with lesser sensitivity, ICI 182780. Restricted to the cytoplasm, Cre-ERT2 can only gain access to the nuclear compartment after exposure to tamoxifen. To counteract the mixed estrogen agonist effects of tamoxifen injections, which can result in late fetal abortions in pregnant mice, progesterone may be coadministered.

Use of MICE by companies or for-profit entities requires a license prior to shipping.

These Brs3-2A-CreERT2 mice have Cre-ERT2 knocked into the bombesin-like receptor 3 gene (Brs3). Expression of Brs3 is reduced, but not abolished. This strain may be useful for mediating inducible cre recombination in Brs3-expressing tissues, as well as for studying energy homeostasis.

Typically mice are recovered in 12-16 weeks. Contact Customer Service to place an order or for more information.

<a target="_blank" href="https://www.jax.org/jax-mice-and-services/customer-support" rel="noreferrer">Contact Customer Service</a> for more information.