Estrogenic control of germ cell differentiation in medaka: independence of early sex dimorphism from zygotic estrogen and receptor signaling

Our results demonstrate that estrogen signaling, both at the ligand and receptor levels, is dispensable for establishing the early germ cell sex difference but essential for subsequent oocyte meiotic progression and ovarian fate maintenance. This establishes a two-step estrogenic control model, redefining the developmental timing of estrogen action during the early phase of gonadal differentiation in vertebrate reproduction.