Fig. 8. Role of BMP-15 and BMP-6 in the anti-apoptotic actions of oocytes on cumulus cells. OOX co-cultured with denuded oocyte (25 DOs) were treated with 50 µg/ml follistatin, 20 µg/ml BMP-6 NAb, or a combination of the two (A). Both follistatin and the BMP-6 NAb were effective at partially antagonizing the anti-apoptotic effects of oocytes, however neither completely restored apoptosis to OOX levels, either alone or combined. Co-culturing OOX with DO or treatment with BMP-15 alone or BMP-6 alone decreased cumulus cell apoptosis (B). Combined treatment of OOXs with BMP-6 and BMP-15 did not further decrease apoptosis levels beyond that of BMP-15 alone, suggesting no additive effect of these two BMPs. Bars represent average percentage of apoptotic cumulus cells (mean ±s.e.m.). Values from bars with different labels; ^a,b,cdiffer significantly (P<0.001).