The steroid hormone estriol (E3) regulates epigenetic programming of fetal mouse brain and reproductive tract

We identify an unexpected functional role for E3 in fetal reproductive system and brain. We further identify a novel mechanism of estrogen action, through recruitment of epigenetic modifiers to estrogen receptors and their target genes, which does not correlated with the traditional view of estrogen potency. We administered E3 to pregnant mice, exposing the fetus to E3 and identified an unexpected functional role for E3 and a novel mechanism of estrogen action.