Skip to main content
. Author manuscript; available in PMC: 2013 Aug 1.
Published in final edited form as: Fertil Steril. 2012 Jun 15;98(2):487–495.e1. doi: 10.1016/j.fertnstert.2012.05.015

Figure 4.

Figure 4

Proposed PDE9 activity pathway in the oocyte. (A) cGMP from granulosa cells is actively transported through gap junctions into the GV oocyte. Elevated levels of cytoplasmic cGMP inhibit PDE3A hydrolysis of cAMP and maintain the oocyte in meiotic arrest. Based on our data, following the LH surge, gap junctions are closed, and residual cGMP is degraded by PDE9 (B). Decreased levels of cGMP permit PDE3A mediated hydrolysis of cAMP, lowering the cytoplasmic concentration and inducing meiotic resumption.