Figure 6.

Oocytes suppress Nrip1 mRNA expression in cumulus cells. A, Localization of Nrip1 transcripts was determined by in situ hybridization. Bar, 300 μm. B, Freshly isolated cumulus cells (CC) express significantly lower levels of Nrip1 transcripts compared with mural granulosa cells (MG). *, P < 0.05. C, Oocytes (Oo) suppress Nrip1 mRNA expression in cumulus cells in vitro. D, Effects of recombinant proteins on Nrip1 mRNA levels in OOX cumulus cells were assessed by real-time PCR. E, Cumulus cells of Bmp15^−/− and Bmp15^−/− /Gdf9^+/− mice express significantly higher levels of Nrip1 transcripts. The values indicated by different alphabetical letters (a, b, and c) are significantly different (P < 0.05). F, Hypothesis depicting possible role of NRIP1 in cumulus cells in mediating the coordination of estrogen and oocyte-drived signals (please see text for details). eCG, Equine choriogonadotropin.