Yamaguchi Shinpei, Kurimoto Kazuki, Yabuta Yukihiro, Sasaki Hiroyuki, Nakatsuji Norio, Saitou Mitinori, Tada Takashi
Stem Cell Engineering, Institute for Frontier Medical Sciences, Kyoto University, 53 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto 606-8507, Japan.
Development. 2009 Dec;136(23):4011-20. doi: 10.1242/dev.041160.
The pluripotency factor Nanog is expressed in peri-implantation embryos and primordial germ cells (PGCs). Nanog-deficient mouse embryos die soon after implantation. To explore the function of Nanog in germ cells, Nanog RNA was conditionally knocked down in vivo by shRNA. Nanog shRNA transgenic (NRi-Tg) mice were generated through the formation of germline chimeras with NRi-Tg embryonic stem cells. In E12.5 Cre-induced ER-Cre/NRi-Tg and TNAP-Cre/NRi-Tg double-transgenic embryos, the number of alkaline phosphatase-positive and SSEA1-positive PGCs decreased significantly. In the E9.5 and E10.5 migrating Nanog-knockdown PGCs, TUNEL-positive apoptotic cell death became prominent in vivo and in vitro, despite Oct4 expression. Single-cell microarray analysis of E10.5 Nanog-knockdown PGCs revealed significant up- and downregulation of a substantial number of genes, including Tial1, Id1 and Suz12. These data suggest that Nanog plays a key role in the proliferation and survival of migrating PGCs as a safeguard of the PGC-specific molecular network.
多能性因子Nanog在植入前胚胎和原始生殖细胞（PGCs）中表达。Nanog基因敲除的小鼠胚胎在植入后不久死亡。为了探究Nanog在生殖细胞中的功能，通过shRNA在体内条件性敲低Nanog RNA。通过将NRi-Tg胚胎干细胞形成种系嵌合体，产生了Nanog shRNA转基因（NRi-Tg）小鼠。在E12.5 Cre诱导的ER-Cre/NRi-Tg和TNAP-Cre/NRi-Tg双转基因胚胎中，碱性磷酸酶阳性和SSEA1阳性的PGCs数量显著减少。在E9.5和E10.5迁移的Nanog敲低的PGCs中，尽管有Oct4表达，但TUNEL阳性的凋亡细胞死亡在体内和体外都变得很突出。对E10.5 Nanog敲低的PGCs进行单细胞微阵列分析，发现大量基因存在显著的上调和下调，包括Tial1、Id1和Suz12。这些数据表明，Nanog作为PGC特异性分子网络的一种保障，在迁移的PGCs的增殖和存活中起关键作用。
