Effects of cilostamide and/or forskolin on the meiotic resumption and development competence of growing ovine oocytes selected by brilliant cresyl blue staining

The relevance of low developmental competence of in vitro-matured oocyte to the incomplete/delayed cytoplasmic maturation, and the heterogeneity of retrieved oocytes is well established in several species. A short phase of prematuration culture was used to allow better oocyte cytoplasmic maturation. The preselection of growing and fully grown oocytes has been proposed to improve developmental competency. This study investigated the effects of phosphodiesterase type 3–specific inhibitor, cilostamide, and adenylate cyclase activator, forskolin, on the resumption of meiosis and developmental competence of growing ovine oocytes selected by brilliant cresyl blue (BCB) staining. Results indicate that cilostamide, forskolin, and their combination significantly (P < 0.05) increased the percentage of growing (BCB−) oocytes maintained at the germinal vesicle stage. However, only forskolin significantly (P < 0.05) increased the yield and quality of blastocysts derived from BCB− oocytes compared with non–BCB-treated oocytes. We conclude that a short prematuration culture with forskolin may improve the in vitro developmental competency of growing oocytes in ovine.