核移植与供体细胞

Nuclear transfer and donor cells

"多莉"羊的诞生是生物界的一个里程碑,它之所以引起如此大的轰动主要是因为它来源于培养的成年绵羊乳腺上皮细胞,这是人类第一次证明分化的体细胞可以被重编程后恢复全能性并最终分化发育成一个动物个体。这说明哺乳动物分化的体细胞核仍具有全套的遗传物质并能够被卵母细胞逆转恢复全能性。然而,关于多莉的供体细胞来源却一直是克隆领域的一个谜。由于体细胞克隆的效率非常低,而用于核移植的供体细胞悬液中往往含有多种类型的细胞,这使得我们很难确切地知道最终获得的克隆动物是来源于哪一种细胞。这种不确定性给我们研究核移植诱导体细胞重编程的机制带来了很大的困难,因此,对供体细胞的研究也是核移植研究领域的一个重要课题,这包括各种组织来源的体细胞是否均可以用于核移植,终末分化的体细胞是否能够用于核移植,组织干细胞是否更有利于体细胞重编程,供体细胞的分化状态是否与核移植的效率有关,死亡的体细胞是否也可以用于核移植等等。本文综述了核移植中与供体细胞相关的最新研究进展。

Dolly, the first cloned animal from cultured adult cell, proved that differentiated somatic cell can be reprogrammed to totipotent status in oocyte and reconstructed embryo can develop to adult. However, the donor cell origin of Dolly remained a complete mystery. Because of the low efficiency of somatic cloning and more than one type of cell involved in donor cell suspension, it is difficult to confirm which kind of donor cells developed to cloned animals after nuclear transfer （NT）. The uncertainty of the donor origin of cloned animals brings difficulties to the research of somatic reprogramming mechanism after NT. Therefore, the study of donor cell is an important subject of nuclear transfer, which includes whether all kinds of cells can be used for nuclear transfer, whether terminally differentiated somatic cells can be reprogrammed after NT, whether differentiated status of donor cells is related to the efficiency of NT, whether nonviable donor cells can be used for nuclear transfer and so on. This review discusses the recent advances of donor ceils used in mammalian somatic nuclear transfer.