Effect of hormones, follicular fluid, serum and media on in vitro maturation of porcine oocyte

Abstract

The present study was conducted to evaluate the effect of hormones, follicular fluid, serum and media on in vitro maturation (IVM) of porcine oocyte. The procedures of IVM could be used for basic research purposes or commercial utilization. The IVM of oocyte is a critical step in in-vitro embryo production and it needs to be carried out in a precise manner under optimal conditions for subsequent fertilization and embryo development. For this purpose ovaries were collected from slaughtered pigs from an abattoir. Ovaries (1,232) were aspirated in 52 trials for IVM and fertilization for this study. Dulbecco Modified Eagle's medium (DMEM) or tissue culture medium (TCM-199) supplemented with gentamycin (50μl/ml), sodium pyruvate (100 mmol) and 10% serum, viz. estrus sow serum (ESS) or fetal calf serum (FCS) with or without porcine follicular fluid (PFF) and hormones such as pregnant mare serum gonadotropin (PMSG) and human chorionic gonadotropin (HCG) were used. The maturation was assessed by loosening of cumulus cells, enlargement of peri-viteline space or extrusion of first polar body and examination of metaphase II by aceto-orcein stain. The results revealed that DMEM with ESS yielded 53% while TCM+ESS yielded 45% maturation rates. The replacement of ESS with FCS resulted in 48.50 and 35.33% maturation in DMEM and TCM-199 medium, respectively. The addition of PFF in DMEM+ESS improved the maturation rate and was found better (74.55%) than TCM-199+ESS (65.35%). However, the replacement of ESS by FCS in either DMEM orTCM-199+PFF did not differ significantly. It can be concluded from the present study that use of DMEM+ESS+PFF along with hormones PMSG + luteinizing hormone (LH) for first 20- 24 h followed by hormone free medium for next 20- 22 h i.e. 42-44 h gave optimum (81.5%) in-vitro maturation rates in pigs. DMEM with ESS and PFF with hormone (PMSG/HCG) yielded highest maturation (81.50%) rate than TCM-199 with ESS, PFF and hormone (PMSG/HCG) which showed maturation rate of 76.59%.