Improve the meiotic competence of growing porcine oocytes from preantral follicle

Abstract

In this study, we evaluated the effect of in vitro growth culture on meiotic competence and fertilization ability of porcine oocytes derived from preantral follicles (2–3 mm in diameter). It is reported that these growing oocytes were not able to obtain full meiotic competence after normal maturation culture. Therefore, oocyte—granulose cell complexes (OGCs) were cultured in vitro growth for 24 h in medium supplemented with 1 mM dbcAMP, 0.01 IU/mL FSH, 0.001 mg/ml 17β Estradiol and 10 ng/ml Androstenedione; then subsequent to in vitro maturation culture for 48 h before undergoing in vitro fertilization. After in vitro maturation, the percentage of growing oocytes reaching to metaphase II was similar to fully-grown oocytes collected from large antral follicles (4–6 mm in diameter). However, the fertilization ability of growing oocytes after in vitro growth was still lower compared to that of fully-grown oocytes (16 and 37%, respectively). Thus, the growing oocytes from 2 to 3 mm follicles should be pre-culture in vitro growth before undergoing in vitro maturation.