克隆猪技术及其在转基因猪研究中的应用

哺乳动物核移植技术是一种可以获得基因组遗传信息完全相同的后代的生物技术。猪体细胞核移植技术包括以下几个环节：卵母细胞的体外成熟、供体细胞的分离和处理、体细胞的核转移、重构胚胎的人工激活、胚胎体外培养和胚胎移植。由于该技术在最近几年的迅速发展，很多实验室已通过该技术成功获得了克隆猪后代。核移植克隆猪技术的出现为生产转基因猪提供了一种有效的方法，并且是目前生产基因打靶猪的惟一方法。至今利用克隆猪技术已经成功获得了一系列的转基因猪和基因敲除猪。以核移植技术产生基因修饰猪目前正处于从基础研究走向应用的过渡阶段。尽管猪体细胞核移植克隆的效率（出生克隆猪数占所用卵数的比例）还不高，但是由于通过该技术能够对猪基因组进行特定的修饰，确保生产的克隆动物100％为转基因动物，从而大大提高了转基因猪的制作效率，可以预料猪核移植技术将会对医药业和农业产生重大的影响。

The applications of nuclear transfer technology in production of transgenic pigs

Nuclear transfer （NT） is a procedure by which genetically identical offspring can be generated. The technology of pig somatic NT, including in vitro maturation of oocytes, isolation and treatment of donor cells, artificial activation of reconstructed oocytes, embryo culture and embryo transfer, has been intensively studied in recent years. The progress has resulted in birth of cloned pigs in many labs. Pig cloning provides an efficient method for producing transgenic pigs, further more, it is the only approach which has been used to produce gene-targeted pigs so far. The production of pigs with genetic modification by NT is now in the transition from investigation to practical use. Although the efficiency of somatic cell NT in pig, when measured as development to term as a proportion of oocytes used, is low, the ability of making specific modifications to the swine genome and every cloned offspring containing foreign genes can promote the efficiency to make transgenic pigs largely, which will make a technology having a large impact not only on medicine but also on agriculture.