Fig. 3. Inability of recombinant BMP15 alone, or in combination with GDF9, to stimulate expression of Pfkp or Ldha mRNA in cumulus cells. Recombinant BMP15 suppressed FSH-induced Lhcgr mRNA expression in mural granulosa cells and promoted cumulus expansion, but did not promote expression of Pfkp and Ldha mRNA in OOX cumulus cells. (A) Mural granulosa cells were cultured with recombinant BMP15 or oocytes (2 oocytes/µl) in the presence of FSH, and Lhcgr mRNA expression in the mural granulosa cells was examined. (B) OOX cumulus cells were treated with recombinant BMP15 or oocytes (2 oocytes/µl) in the presence of EGF, and degree of cumulus expansion was examined. (C) Representative photographs of expanded OOX cumulus cells treated with oocytes (left) or recombinant BMP15 (right). Scale bar: 500 µm. (D) OOX cumulus cells were treated with recombinant BMP15 or oocytes (2 oocytes/µl) and expression levels of Pfkp and Ldha mRNA in OOX cumulus cells were examined. (E) OOX cumulus cells were treated with recombinant BMP15 (500 ng/ml), GDF9 (500 ng/ml) or both, or co-cultured with oocytes (2 oocytes/µl) and expression levels of Pfkp and Ldha mRNA in OOX cumulus cells were examined. Mean±s.e.m. The values indicated by different letters (a, b, c and d) are significantly different (P<0.05).