... embryos actively regulate their exposure to maternal testosterone through steroid metabolism, suggesting testosterone metabolites, not testosterone, may elicit the observed phenotypic effects. To address the role steroid metabolism plays in mediating yolk testosterone effects, we used European starling...

... for regulating maternal steroid exposure in oviparous vertebrates. Summary: Steroid sulfatase activity hydrolyzes steroid sulfates back to an active form. Here we demonstrate steroid sulfatase is present in various tissues during embryonic development. Steroid metabolism Oviparous vertebrate...