Estrogen receptor knockout mice: phenotypes in the female reproductive tract

Abstract

There is a broad spectrum of organ systems that respond to estrogen hormones ,including the female and male reproductive tracts ,mammary gland ,the skeleton ,cardiovascular system and central nervous system.The physiological effects of estrogens are mediated by the estrogen receptor ,a member of the nuclear receptor superfamily of transcription factors. Two estrogen receptors have been identified: the originallydescribed estrogen receptor α (ERα) and the more recently discovered estrogen receptor β (ERβ). Three different estrogen receptor knockout (ERKO) mouse models were generated ,carrying a nullmutation in the ERα gene (αERKO) ,the ERβ gene (βERKO) or both genes (αβERKO). The generation of the different ERKO mice provides ideal models for studying the physiologicalconsequences of the complete lack of estrogen receptor activity and the distinct roles of both estrogen receptors in various tissues. This review summarizes the phenotypes principally seen in the femalereproductive system of the different ERKO mice.