Fig. 9.

A Possible Signaling Pathway that Mediates FSH-Induced Meiotic Resumption of Mouse Oocytes

After binding with its membrane-integrated receptor in cumulus cells, FSH uses PKAII as a downstream mediator after a transient increase of cAMP. PKAII leads to AR and CYP51 expression with the mediation of CREB. CYP51 probably participates in the regulation of MAPK activation by mediating downstream steroidogenesis during oocyte maturation. In addition, CYP51 activity may be involved in EGF-induced MAPK phosphorylation and oocyte meiotic resumption. cat, Catalytic unit; CBP, CREB-binding protein; FSHR, FSH receptor.