Bone Morphogenetic Protein-6 (BMP-6) induces atresia in goat primordial follicles cultured in vitro

Araujo V.R., Lima-Verde I.B., Name K.P.O., Bao S.N., Campelo C.C., Silva J.R.V., Rodrigues A.P.R. & Figueiredo J.R. 2010. Bone Morphogenetic Protein-6 (BMP-6) induces atresia in goat primordial follicles cultured in vitro. Pesquisa Veterinaria Brasileira 30(9):770-776. Programa de pos-Graduacao em Ciencias Veterinarias, Laboratorio de Manipu-lacao de Oocitos e Foliculos Pre-Antrais, Universidade Estadual do Ceara, Av. Paranjana 1700, Campus do Itaperi, Fortaleza, CE 60740-000, Brazil. E-mail: val_exclusiva@yahoo.com.br This study investigated the effects of bone morphogenetic protein 6 (BMP-6) on in vitro primordial follicle development in goats. Samples of goat ovarian cortex were cultured in vitro for 1 or 7 days in Minimum Essential Medium (control medium) supplemented with different concentrations of BMP-6. Follicle survival, activation and growth were evaluated through histology and transmission electron microscopy (TEM). After 7 days of culture, histological analysis demonstrated that BMP-6 enhanced the percentages of atretic primordial follicles when compared to fresh control (day 0). Nevertheless, BMP-6 increased follicular and oocyte diameter during both culture periods. As the culture period progressed from day 1 to day 7, a significant increase in follicle diameter was observed with 1 or 50ng/ml BMP-6. However, on the contrary to that observed with the control medium TEM revealed that follicles cultured for up to 7 days with 1 or 50ng/ml BMP-6 had evident signs of atresia. In conclusion, this study demonstrated that BMP-6 negatively affects the survival and ultrastructure of goat primordial follicles.