Placental abnormalities in mouse embryos lacking the orphan nuclear receptor ERR-beta

The orphan nuclear receptor ERR-beta is not activated by oestrogens, and its expression during embryogenesis defines a subset of extra-embryonic ectoderm, later forming the chorion dome. This suggests that ERR-beta is involved in early placental development. It was found that homozygous mutant embryos generated by targeted disruption of the Estrrb gene suffered sever placental formation impairment and showed abnormal chorion development.