查看文章

The estrogen receptor-α (ERα) is a critical transcription factor that regulates epithelial cell proliferation and ductal morphogenesis during postnatal mammary gland development. Tissue recombination and transplantation studies using the first generation of ERα knockout (ERKO) mice suggested that this steroid hormone receptor is required in the mammary stroma that subsequently exerts its effect on the epithelium through additional paracrine signaling events. A more detailed analysis revealed that ERKO mice produce a truncated ERα protein with detectable transactivation activity, and it is likely that this functional ERα variant has masked the biological significance of this steroid receptor in the mammary epithelium. In this article, we describe the generation a Cre-lox-based conditional knockout of the ERα gene to study the biological function of this steroid receptor in the epithelial compartment at defined stages of …