Effect Of Nerve Growth Factor On Pig Oocyte Maturation In Vitro

The aim of this work is to assess the effect of NGF on maturation in vitro. In thisstudy, a series of experiments were taken with the ovary come from local slaghterhouse in order to find out the effect of NGF on oocyte nuclea maturation, cumuluscells expansion, parthenogenesis activation and the expression of gonadotropin receptors. Andthe results as follows:The mRNA and protein of NGF and its receptor TrkA are found in COCs, and the distributionof the protein is also be determined: TrkA widely distributed in oocyte and cumulus cells whileNGF could only be found in cumulus cells.Different concentration of NGF has different effects onnuclea maturation. The in vitro mature system supplied with5ng/ml NGF could not makesignifant different comparing with the control group, while the concentration turns to50ng/ml and500ng/ml, more oocytes tend to stay at GV stage, although the rate of MII stage is not significantdifferent from that of control group. And there is no significant different between the two groups.In vitro maturation culture medium supplied with NGF at the concentration of50ng/ml would significantly increase the proportion of oocytes that reached MⅡstage with the combination of gonadotropin.No significant differences was found interms of cumulus expansion and parthenogenesis activation when oocytes were cultured inthe medium supplied with50ng/ml NGF. Cultured in medium supplied with50ng/ml，theexpression of gonadotropins receptors mRNA in COCs was not increased.In all, NGF could have a direct effect on porcine oocyte maturation with a higherproportion of oocytes stayed at GV stage; meanwhile, it could increase the proportionof oocytes that reached MⅡ stage with the combination of gonadotropins, which isnot assumed to be accomplished by increasing the expression of gonadotropinsreceptors’ mRNA transcription.