Abstract:

【Objective】 This study was performed to increase the efficiency of goat cumulus cell nuclear transfer. 【Method】Based on the problem of low efficiency of goat somatic nuclear transplantation (SNT), the application of demecolcine was used to increase goat oocytes enucleation rate, the effects of 5-aza-dC and Trichostatin A (TSA) were also investigated when cumulus cells were treated with them on the development rate of goat cloned embryos. 【Result】 The optimum concentration of demecolcine for chemically assisted enucleation was 0.5 μg?mL-1 and the extrusion cones rate of goat oocytes was 91.67% (P＜0.05). Compared with blind enucleation method, the enucleation rate of demecolcine assisted-enucleation method was 100% and increased significantly (P＜0.05). Furthermore, the morula rate and blastula rate of cloned embryos reconstrusted by demecolcine assisted-enucleation method were 25.23% and 13.08%, which were significantly higher than that of embryos reconstrusted by blind enucleation method (P＜0.05). At the same time, it was found that the blastula rate and morula rate of goat cloned embryos reconstructed by cumulus cells treated with 0.01μmol?L-15-aza-dC was 16.96% and 30.41%, which were extremely higher than that of other groups (P＜0.05). When the goat cloned embryos reconstructed by cumulus cells treated with 400 nmol?L-1 TSA, the rate of morula and blastula was 31.52% and 15.22%. 【Conclusion】The enucleation rate of chemically assisted enucleation method was significantly higher than that of blind enucleation method. The effect of goat cloned embryos reconstructed by cumulus cells treated with 0.01 μmol?L-1 5-aza-dC or 400 nmol?L-1 TSA was the best.

Key words: goat, cumulus cell, nuclear transfer efficiency