Abolition of the sex difference in Ngn3 by estradiol is depending on sex chromosome complement

Abstract

A growing body of evidences indicates that some sexually dimorphic traits cannot be solely explained as a result of gonadal steroid action during the critical period of brain masculinization (E18-PN10). Neurogenin 3 (Ngn3), a gene located in mouse chromosome 10 (MGI:893591), is involved in neuritogenesis and morphological differentiation of hippocampal neurons (Salama-Cohen et al., 2006). Recent works from our laboratory have shown the existence of sex difference in the neuritogenic transcription factor Ngn3 in hypothalamic neurons before brain masculization. Moreover 17β-estradiol (E2) abolishes this sex difference (Scerbo et al., 2014). The sex difference in Ngn3 in hypothalamic neurons is depending on sex chromosome complement (Scerbo et al., 2014). In order to study if cell-autonomous actions of sex chromosomes are involved in the effect of E2 on Ngn3, we evaluated Ngn3 mRNA in neuronal cultures.