Wakisaka-Saito Noriko, Kohda Takashi, Inoue Kimiko, Ogonuki Narumi, Miki Hiromi, Hikichi Takafusa, Mizutani Eiji, Wakayama Teruhiko, Kaneko-Ishino Tomoko, Ogura Atsuo, Ishino Fumitoshi
Department of Epigenetics, Medical Research Institute, Tokyo Medical and Dental University, 2-3-10 Kandasurugadai, Chiyoda-ku, Tokyo 101-0062, Japan.
Biochem Biophys Res Commun. 2006 Oct 13;349(1):106-14. doi: 10.1016/j.bbrc.2006.08.057. Epub 2006 Aug 22.
Somatic cell nuclear transfer technology has been applied to produce live clones successfully in several mammalian species, but the success rates are very low. In mice, about half of the nuclear transfer embryos undergo implantation, but very few survive to term. We undertook detailed histological analyses of placentas from cloned mouse embryos generated from cumulus cells at 10.5 dpc of pregnancy, by which stage most clones have terminated their development. At 10.5 dpc, the extraembryonic tissues displayed several defined histological patterns, each reflecting their stage of developmental arrest. The most notable abnormality was the poor development of the spongiotrophoblast layer of diploid cells. This is in contrast to the placental hyperplasia frequently observed in somatic clones at 12.5 dpc or later stages. A variety of structural abnormalities were also observed in the embryos. Both placental and embryonic defects likely contribute to the low success rate of the mouse clones.
体细胞核移植技术已成功应用于多个哺乳动物物种以产生活体克隆动物，但成功率非常低。在小鼠中，约一半的核移植胚胎会着床，但只有极少数能发育至足月。我们对妊娠10.5天由卵丘细胞产生的克隆小鼠胚胎的胎盘进行了详细的组织学分析，到这个阶段大多数克隆胚胎已经终止发育。在妊娠10.5天时，胚外组织呈现出几种明确的组织学模式，每种模式都反映了它们发育停滞的阶段。最显著的异常是二倍体细胞的海绵滋养层发育不良。这与在妊娠12.5天或更后期的体细胞克隆中经常观察到的胎盘增生形成对比。在胚胎中还观察到了多种结构异常。胎盘和胚胎缺陷可能都导致了小鼠克隆成功率低。
