Modification of the medium volume and gel substrate under in vitro culture conditions improves growth of porcine oocytes derived from early antral follicles.

ABSTRACT

This study compared the effects of different volumes of culture medium for the in vitro growth of oocytes derived from porcine early antral follicles (EAFs). Oocyte granulosa cell complexes (OGCs) were collected from EAFs (0.5-0.7 mm in diameter) and individually cultured for 14 days. When OGCs were cultured in 1 ml of medium with or without polyacrylamide gel (PAG), the presence of PAG supported granulosa cell (GC) proliferation and oocyte growth. When OGCs were cultured in 0.2 or 1 ml of medium on PAG, the number of GC in the OGC culture and the developmental ability of the oocytes cultured in vitro were significantly higher for the 1 ml of culture medium group than for the 0.2 ml group. In conclusion, a combination of a large volume of culture medium with PAG improved the growth and developmental ability of the oocytes cultured in vitro, which were comparable to the oocytes collected from large antral follicles.