Practice question

Formation of bipotential gonad prior to sex determination depends on transcription factors Sf1/Nr5a1, Wt1, Lhx9 and Gata4 establishing competence in coelomic epithelium and underlying mesonephric mesenchyme. Wt1 together with Sf1 activates genes for proliferation and survival of gonadal primordium; Lhx9 maintains division preventing apoptosis-induced regression; Gata4 cooperates with Fog2 enabling genital ridge thickening and marker expression. Mutations cause complete gonadal agenesis or streak gonads, not mere sex reversal. In contrast Sry and Sox9 drive later testis fate, while β-catenin and Wnt4 act later for ovary.