Abstract: The literature shows that electrofusion parameters，fusion methods and treatment methods of cloned embryos may affect the in vitro development efficiency of porcine cloned embryos.The effects of synchronous activation and delayed activation on in vitro and in vivo development efficiency of porcine cell cloned embryos were compared.All embryos were placed in PZM⁃3 culture medium containing 5 μg/mL of cytochalasinB（CB）for 4h after activation. There was no significant difference in the fusion rate between the two groups（P>0.05），but the cleavage rate and blastocyst development rate of delayed activation were higher than those of synchronous activation group.CB and histone deacetylase inhibitor are also commonly used in the treatment of activated cloned embryos. This study also compared the treatment with cytorelaxin B after delayed activation and the treatment with histone deacetylase inhibitor scriptaid，and found that the latter was more conducive to improving the efficiency of in vitro embryo development.The cloned embryos obtained by the above different methods were transferred，and the statistical results showed that the delayed activation method was more conducive to embryo development. After delayed activation，CB or scriptaid was used to treat the embryos，and the pregnancy rate and cloning efficiency after transplantation were significantly higher than those in the synchronous activation group.

Key words: Pig, Somatic cell cloning, Delayed activation, Processing mode, Developmental efficiency

摘要： 研究表明，电融合参数、融合方式、克隆胚胎的处理方式都有可能影响猪克隆胚胎 体外发育效率。该文对比了同步激活和延迟激活对猪体细胞克隆胚胎体外、体内发育效率的 影响。胚胎激活后都放入含5 μg/mL细胞松弛素B（cytochalasin B，CB）的PZM?3培养液中处理 4 h，发现两者融合率差异不显著（P>0.05），但延迟激活的卵裂率和囊胚发育率都要高于同步 激活组；CB与去乙酰化酶抑制剂也常用于处理激活后的克隆胚胎，该研究同时比较了延迟激 活后用CB和用去乙酰化酶抑制剂scriptaid处理猪克隆胚胎，结果发现后者更有利于提高体外 胚胎发育效率；将上述不同方式所得克隆胚胎进行移植，统计结果发现，延迟激活方法更有利 于胚胎发育，延迟激活后采用CB或者scriptaid处理胚胎，移植后妊娠率和克隆效率都显著高 于同步激活组。

关键词: 猪, 体细胞克隆, 延迟激活, 处理方式, 发育效率