Effect of sequential medium with fibroblast growth factor-10 and follicle stimulating hormone on in vitro development of goat preantral follicles

• Sequential medium affected long term in vitro culture of goat preantral follicles.
• Follicle survival was higher in sequential medium contained FSH followed by FGF-10.
• Follicular ultrastructure was maintained after long term culture in FSH/FGF-10.
• Media contained (FSH/FGF-10 and FSH/FSH) promoted follicle activation and growth.

A sequential medium with fibroblast growth factor-10 (FGF-10) and follicle stimulating hormone (FSH) was evaluated on the survival, ultrastructure, activation and growth rate of caprine preantral follicles submitted to long-term culture, aiming to establish an ideal in vitro culture system. Ovarian fragments were cultured for 16 days in α-MEM+ alone or supplemented with FGF-10 and/or FSH added sequentially on different days of culture. Ovarian fragments were cultured during the first (days 0–8) and second (days 8–16) halves of the culture period, generating 10 treatments: α-MEM+/α-MEM+ (cultured control), FSH/FSH, FSH/FGF-10, FSH/FSH + FGF-10, FGF-10/FGF-10, FGF-10/FSH, FGF-10/FSH + FGF-10, FSH + FGF-10/FSH + FGF-10, FSH + FGF-10/FSH and FSH + FGF-10/FGF-10. Follicle morphology, viability and ultrastructure were analyzed. The FSH/FGF-10 treatment showed a higher (P < 0.05) percentage of normal follicles compared to all other treatments. In addition, follicles from the FSH/FGF-10 treatment maintained ultrastructural integrity after the culture period. After 16 days of culture, the FSH/FGF-10 and FSH/FSH treatments showed a higher percentage of activation compared to the cultured control (α-MEM+/α-MEM+). Moreover, the FSH/FGF-10 treatment promoted greater follicular and oocyte diameters compared to the fresh control. In conclusion, this study showed that a sequential medium with FSH followed by FGF-10 (FSH/FGF-10 and FSH/FSH) maintains follicular viability and ultrastructure and promotes transition from the primordial to primary stage (activation) and growth in goat preantral follicles cultured in vitro.