FSH acts on the proliferation of type A spermatogonia via Nur77 that increases GDNF expression in the Sertoli cells

► FSH induces the expression of Nur77 and GDNF in testes and fetal Sertoli cells. ► Exogenous FSH increases the number of A spermatogonia co-cultured with Sertoli cells. ► FSH-induced Nur77 directly regulates the expression of GDNF in the Sertoli cells. ► FSH signaling pathway plays an important role in A spermatogonia proliferation.