牛胚胎原代和继代细胞核移植结果比较

A Preliminary Comparison between Bovine Cloned and Recloned Embryos

比较了原代和继代核移植的操作各环节以及核移植胚胎在体外发育能力上的差异。通过显微操作将体外受精发育而来的８～３２细胞期胚胎的单个卵裂球注入激活的去核卵母细胞的卵周隙内，并用８０Ｖ/mm、４０us２次电脉冲诱导卵裂球与去核卵母细胞融合，借此进行牛胚胎的原代核移 体外发育来的８～３２细胞期的原代核移植胚胎作为供体，用原代核移植相同的方法进行牛胚胎的继代移植。原代核移植的存活率和融合率（８７．３％和６８．

Bovine cloned embryos were compared with recloned embryos in some aspect of nuclear transfer manipulation and the ability of in vitro development. A single blastomere from 8 32 cell bovine embryos, which fertilized and developed in vitro, was microinjected into the perivitelline space of the activated and enucleated oocyte. The fusion between the blastomere and the enucleated oocyte was induced with two 80 V/mm 40 μs DC electric pulses. Bovine embryos were cloned by this procedure. Bovine cloned embryos were recloned by using 8 32 cell cloned embryos as the donors and using the same procedure as above. Bovine cloned embryos were not different significantly with the recloned embryos in survival rate and fusion rate (87.3% and 68.5% vs. 87.9% and 64.7%, P>0.05). Although the cleavage rate of recloned embryos was the same as that of the cloned embryos, the developmental rate of morulae and blastocysts of recloned embryos were lower than that of the cloned embryos significantly (7.6% vs. 28.0%, P<0.001). The study indicated that bovine embryo recloning is similar to the embryos cloning except for the embryo′s low in vitro development ability.