Estrogen receptor knock-out mice: Molecular and endocrine phenotypes

Using gene-targeting techniques, transgenic, knock-out (KO) mice, homozygou s for the disrupted estrogen receptor alpha (alpha ERKO) and beta gene (bet a ERKO) have been produced. Estrogen receptor (ER) beta expression does not appear to be dependent on ER alpha expression. Progesterone receptor (PR) mRNA is detected in alpha ERKO mice and appears to have both estrogen-indep endent and -dependent gene regulation. The phenotypic differences in alpha ERKO and beta ERKO mice are described. Additional studies will further defi ne the specific roles of ER alpha and ER beta in various tissues. (J Soc Gy necol Investig 2000;7:S16-7) Copyright (C) 2000 by the Society for Gynecolo gic Investigation.