Studies On In Vitro Developmental Potential Of Porcine Cumulus Cells Free Oocytes

The present thesis studied the maturation and subsequent developmental potential of porcine cumulus free oocytes after parthenogenetic activation.Such research could be indicative to elucidate the the mechanism of oocytes maturation and offer reference to save the endangered species.To investigate the effects of different factors on the porcine denuded oocytes(DOs)in vitro maturation and the developmental potential after parthenogenetic activation,DOs were cocultured with dispersed CCs(group CCscoculture),ooocytectomy(OOX)(group OOXcoculture)in which the oocytes were removed,and intact CUlnulus oocyte complexes(COCs)(goup COCscoculture).In addition,DOs were cultured alone supplemented with epidermal growth factor(EGF), vitamin C(0μM,50μM,100μM,250μM,500μM,750μM)and vitamin E(0μM,10μM,20μM,50μM,100μM,250μM)respectively.We also studied the effects of culture pattens on in vitro maturation and the developmental potential of oocytes after parthenogenetic activation,including DOs alone(group DOs),DOs cocultured with COCs(group coculturedDOs),CEOs cocultured with DOs(group coculturedCOCs)and CEOs alone(group CEOs).The results showed that the supplementation of EGF,vitamin C and vitamin E were ineffective on the maturation rates and blastocyst rates,and the different coculture patterns didn't increase the maturation rates either.In contrast to the control,the coeulture of DOs with cumulus cells(CCs)(19.5%),OOX(45%)or COCs (38.73%)significantly improved the percentage of blastcysts(P＜0.01).When the oocytes were cultured in different pattens,the oocyte maturation rates in group DOs(51.62%) and group cocultureDOs(41.81%)were significantly lower than that in group cocultureCEOs(76.42%)and group CEOs(72.38%)(P＜0.01),but no difference between g_roup DOs and cocultureDOs(P＞0.05)or between group cocultureCEOs and CEOs (P＞0.05);And the blastocyst rate in group DOs(3.57%)was significantly lower than that in three other groups(43.33%,42.65%,45.5%)(P＜0.01).It is concluded that the addition of EGF,vitamin C or E cannot stimulate porcince DOs meiotic maturation and subsequent development ability under the current circumstance,but the developmental potential of DOs can be improved after coculture with OOX or COCs.