Model depicting the role of NPPC and NPR2 and oocyte-derived paracrine factors (ODPF) in the maintenance of oocyte meiotic arrest. See text for details. ADCY, adenylyl cyclase; GPR3/12, G-protein coupled receptors 3 and 12; Gs, GNAS (guanine nucleotide binding protein, alpha stimulating) complex; ODPF, oocyte-derived paracrine factors.