体外培养时间和表皮生长因子对牦牛卵母细胞成熟及孤雌胚胎体外发育的影响

研究在成熟液中添加表皮生长因子（Epidermal growth factor,EGF）以及成熟时间对牦牛卵母细胞体外成熟及孤雌胚胎体外发育的影响,以确立牦牛卵母细胞体外成熟的最佳体系.结果表明,成熟液中添加EGF组的成熟率明显高于未添加组（P＜0.05）,并且牦牛卵母细胞的成熟率随着EGF添加的浓度增加也不断上升;随着体外培养时间的延长,成熟率逐渐增加,培养24 h后成熟率趋于稳定;胚胎体外培养液中添加EGF能显著提高孤雌胚胎的8-细胞和囊胚形成率（P＜0.05）.由此推测：在体外培养22-24 h,且添加40 μg/mL EGF最有利于牦牛卵母细胞体外成熟;胚胎培养液中添加40μg/mLEGF能显著提高牦牛孤雌胚胎的体外发育能力.

The effect of in vitro culture time and EGF on the yak oocyte maturation and parthenogenetic embryos in vitro development

The objective of this study is to determine the effect of epidermal growth thctor and in vitro culture time on the yak oocyte maturation and parthenogenetic embryos in vitro development, so that the optimal system for in vitro maturation of yak oocyte could be established. The results show that the oocyte maturation rate of EGF group is significantly higher than that of untreated groups （P〈0.05）, and yak oocyte maturation rate increases with the concentration of EGF. Along with the in vitro culture time, maturation rate gradually increases, and the maturation rates are stable after being cultured for 24 h; Embryo culture medium with EGF can significantly improve 8-cell and blastocyst formation rates of parthenogenetic embryos （P 〈0.05） Therefore, it is presumed that culturing for 22-24 h and supplement with 40 μg/mL EGF are beneficial for yak oocyte in vitro maturation, and supplement with 40μg/mL EGF in embryo culture medium can significantly improve in vitro developmental competence of yak parthenogenetic embryos.