NR2F2 Regulation of Fetal Leydig Cell Differentiation: Insights into Differences of Sex Development [multiome]
Testicular fetal Leydig cells are specialized for androgen production during embryogenesis. Testosterone is essential for regulating sex differentiation, spermatogenesis, and fertility. Deficiencies in Leydig cell differentiation can lead to various disorders of sex development and male reproductive conditions, such as ambiguous genitalia, hypospadias, cryptorchidism, and infertility. Understanding the differentiation of fetal Leydig cells is essential for comprehending male sexual differentiation, reproductive health, and fertility.  Fetal Leydig cells originate from proliferating progenitor cells in the gonadal interstitium, marked by genes like Arx, Pdgfra, Tcf21, Wnt5a, and Nr2f2. However, the precise mechanisms governing the transition from interstitial cells to Leydig cells remain elusive. Through integrated approaches involving animal models and multiomics, we have demonstrated that fetal Leydig cells originate from a Nr2f2 positive non-steroidogenic interstitial cell population. NR2F2 promotes progenitor cell fate while suppressing Leydig cell differentiation. Moreover, embryonic deletion of Nr2f2 in mouse testes resulted in disorders of sex development, including reduced testicular size, Leydig cell hypoplasia, cryptorchidism, and hypospadias. Collectively, our findings highlight the critical role of Nr2f2 in orchestrating the transition from interstitial cells to Leydig cells during testicular development. Overall design: Homozygous Nr5a1-cre mice were crossed with homozygous Rosa-tdTomato female. Whole testes were collected from E14.5 embryos in PBS and immediately frozen in liquid nitrogen for storage.