Growth Differentiation Factor 9 and Bone Morphogenetic Protein 15 Are Essential for Ovarian Follicular Development in Sheep

Abstract The aim of this study was to test the hypothesis that both growth differential factor 9 (GDF9) and bone morphogenetic protein (BMP15; also known as GDF9B) are essential for normal ovarian follicular development in mammals with a low ovulation rate phenotype. Sheep (9–10 per group) were immunized with keyhole limpet hemocyanin (KLH; control), a GDF9-specific peptide conjugated to KLH (GDF9 peptide), a BMP15-specific peptide conjugated to KLH (BMP15 peptide), or the mature region of oBMP15 conjugated to KLH (oBMP15 mature protein) for a period of 7 mo and the effects of these treatments on various ovarian parameters such as ovarian follicular development, ovulation rate, and plasma progesterone concentrations evaluated. Also in the present study, we examined, by immunohistochemistry, the cellular localizations of GDF9 and BMP15 proteins in the ovaries of lambs. Both GDF9 and BMP15 proteins were localized specifically within ovarian follicles to the oocyte, thereby establishing for the sheep that th...