Hemizygous Wfs1-Tg2-CreERT2 mice are viable and fertile. As the Cre-ERT2 fusion gene is under control of the Wfs1 promoter/enhancer regions within the BAC transgene, cre activity is directed to cortex, hippocampus, and cerebellum only following tamoxifen administration. The donating investigators report that Cre recombinase expression for this Wfs1-Tg2-CreERT2 line is more restricted than the Wfs1-Tg3-CreERT2 line (Stock No. Stock No. 009103). The donating investigators may not have assessed expression in tissues other than brain. 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 (17β-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. When Wfs1-Tg2-CreERT2 mice are bred with mice containing a loxP-flanked sequence of interest, tamoxifen-inducible, Cre-mediated recombination will result in deletion of the floxed sequence(s) in the offspring. As such, these Wfs1-Tg2-CreERT2 mice may be useful for generating conditional mutations for studying gain or loss of function and/or fate mapping in subgroups of brain tissues (including cortex, hippocampus, and cerebellum).
For characterization information, see images at the Allen Institute for Brain Science website (Wfs1-Tg2-CreERT2 images).
