Survival, growth, and hormone production in vitro from preantral follicles of crossbred female goats (Saanen × Anglo-Nubian)

ABSTRACT

The present study aimed to evaluate the survival, growth, antrum formation, oocyte extrusion, and hormone production during in vitro culture of caprine preantral follicles isolated from pure-breed (Saanen) or crossbreed (F1 generation ½ Saanen + ½ Anglo-Nubian) goats. Secondary follicles (diameter 150-250 µm) from Saanen or crossbreed (Saanen × Anglo-Nubian) goats were isolated from the ovarian cortex by microdissection and cultured in vitro for 18 days in α-modified minimum essential medium (α-MEM+) supplemented with vascular endothelial growth factor and increasing concentrations of follicle-stimulating hormone. Every six days follicular morphology, growth, antrum formation, and follicular extrusion were evaluated. In addition, on days 2, 6, 12, and 18 of culture the medium samples were collected and stored at -20°C for further measurement of estradiol and progesterone. The follicular survival, antrum formation, and oocyte extrusion were analyzed by the Chi square test. Follicular diameter and hormone assays were compared using the Kruskal-Wallis test. Survival rates, growth, antral follicle formation, and oocyte extrusion of preantral follicles cultured in vitro were similar between the different genetic groups. The production of estradiol and progesterone indicated the maintenance of cell viability throughout the culture. In conclusion, preantral follicles from pure-breed or crossbreed goats can be used with the same efficiency for in vitro culture of isolated caprine preantral follicles.