Practice question

Nuclear β-catenin accumulation in supporting precursors drives ovarian fate downstream of Wnt4/Rspo1. Ligand binding inhibits destruction complex composed of Axin, Apc and Gsk3β, preventing phosphorylation and proteasomal degradation of β-catenin. Stabilized protein enters nucleus associating with Lef1/Tcf to transcribe Foxl2, Fst and repress Sox9 enhancer. Genetic stabilization of β-catenin in XY gonads induces male-to-female reversal with granulosa differentiation, whereas conditional deletion in XX causes masculinization and ectopic Sox9. Therefore β-catenin favors ovary formation, maintaining follicular organization and germ cell meiosis entry.