Effect of EGF (A), oocyte coculture (B), and TGFβ superfamily proteins (C and D) on expression levels of Spry2 mRNA in OOX cumulus cells. A) OOX cumulus cells were cultured with recombinant EGF, and Spry2 transcript levels were assessed after 6 h. A value with an asterisk is significantly different from the value of the group which was not treated with EGF (P < 0.05). B) OOX cumulus cells were cultured with EGF, and the effect of oocytes (2 oocytes/μl) was examined. An asterisk indicates that the differences of expression levels in OOX cumulus cells cocultured with and without oocytes are statistically significant (P < 0.05). C and D) OOX cumulus cells were cultured with EGF (10 ng/ml) and with or without BMP15 (500 ng/ml), BMP4 (100 ng/ml), BMP6 (100 ng/ml), TGFB2 (10 ng/ml), and GDF9 (500 ng/ml), and Spry2 expression levels were assessed with real-time PCR. The values indicated by different lowercase letters (a–c) are significantly different (P < 0.05). Values are presented as the mean ± SEM.