The Esr1cre (Esr1-Cre) knockin allele harbors an attP-flanked 2A oligopeptide and Cre recombinase gene in the 3' UTR of the estrogen receptor 1 alpha gene (Esr1 or ERα). Under direction of the endogenous Esr1 promoter/enhancer elements, Cre recombinase expression is observed in a pattern similar to that of Esr1. The donating investigator specifically reports Cre recombinase expression in the ventrolateral subdivision of the ventromedial hypothalamus (VMHv1) that, like wildtype mice, is greater in females than males. Expression is also observed in arcuate nucleus (ARH). The donating investigator reports that heterozygous mice are viable, fertile, normal in size and do not display any gross physical or behavioral abnormalities. In 2014, it is the experience of The Jackson Laboratory Repository colony managers that C57BL/6NJ-congenic Esr1-Cre knockin homozygotes of both sexes do not breed well.
ERα, a nuclear hormone receptor (NHR), binds to steroid hormones in the cytoplasm, causing their translocation into the nucleus and leading to increased transcription of target genes. These Esr1-Cre knockin mice may be useful for studying the function of this ligand-inducible transcription factor in neuronal differentiation, sympathetic nervous system development, hypothalamus, female reproductive organs (endometrium and ovarian stroma cells), and male efferent duct epithelial cells. They may also be useful for studying ERα-positive breast cancer and steroid hormone-induced malignancies.
