Combined Effect of Retinoic Acid and Basic Fibroblast Growth Factor on Maturation of Mouse Oocyte and Subsequent Fertilization and Development

Background: Many autocrine and paracrine elements that are produced within follicular niche have been the focus of much in vitro maturation (IVM) research. The present study was carried out to compare retinoic acid (RA) and basic fibroblast growth factor (bFGF) efficacy on IVM of mouse oocytes, and their further dual consumption to reach an optimal protocol. Materials and Methods: In this experimental study, germinal vesicle (GV) oocytes obtained from two-months-old NMRI mice were randomly divided into control, sham and three experimental groups. The basic culture medium was α-MEM supplemented with 10% fetal bovine serum (FBS), 50 mg/l streptomycin, 60 mg/l penicillin and 10 ng/ ml epidermal growth factors. Each of the experimental groups received one of the following treatments: RA (2 μM), bFGF (20 ng/ml) or combination of RA and bFGF with the indicated concentrations. After 24 hours, capacitated spermatozoa were added to in vitro matured oocytes. Five hours later, the oocytes were cultured in fresh droplets of M2 medium for 24 hours and assessed for cleavage to the two-cells stage. Results: As compared with the control group, the rate of maturation was significantly increased in the RA (P<0.001) and bFGF+RA (P<0.02) groups with 58 ± 10 and 57 ± 3.46, respectively. The rate of maturation was significant in the RA (P<0.02) and bFGF+RA (P<0.03) groups, in comparison with the bFGF group. The bFGF+RA group had higher rate (83 ± 1.52) of two-cells development, than control (33 ± 1, P<0.001). Conclusion: Our findings showed beneficial effects of 2 μM RA and 20 ng/ml bFGF combination on mouse oocyte IVM.