Li Hanshuang, Song Mingmin, Yang Wuritu, Cao Pengbo, Zheng Lei, Zuo Yongchun
State Key Laboratory of Reproductive Regulation and Breeding of Grassland Livestock, College of Life Sciences, Inner Mongolia University, Hohhot 010070, China.
State Key Laboratory of Reproductive Regulation and Breeding of Grassland Livestock, College of Life Sciences, Inner Mongolia University, Hohhot 010070, China.
Mol Ther Nucleic Acids. 2020 Mar 6;19:1053-1064. doi: 10.1016/j.omtn.2019.12.035. Epub 2020 Jan 14.
Terminally differentiated somatic cells can be reprogrammed into a totipotent state through somatic cell nuclear transfer (SCNT). The incomplete reprogramming is the major reason for developmental arrest of SCNT embryos at early stages. In our studies, we found that pathways for autophagy, endocytosis, and apoptosis were incompletely activated in nuclear transfer (NT) 2-cell arrest embryos, whereas extensively inhibited pathways for stem cell pluripotency maintenance, DNA repair, cell cycle, and autophagy may result in NT 4-cell embryos arrest. As for NT normal embryos, a significant shift in expression of developmental transcription factors (TFs) Id1, Pou6f1, Cited1, and Zscan4c was observed. Compared with pluripotent gene Ascl2 being activated only in NT 2-cell, Nanog, Dppa2, and Sall4 had major expression waves in normal development of both NT 2-cell and 4-cell embryos. Additionally, Kdm4b/4d and Kdm5b had been confirmed as key markers in NT 2-cell and 4-cell embryos, respectively. Histone acetylases Kat8, Elp6, and Eid1 were co-activated in NT 2-cell and 4-cell embryos to facilitate normal development. Gadd45a as a key driver functions with Tet1 and Tet2 to improve the efficiency of NT reprogramming. Taken together, our findings provided an important theoretical basis for elucidating the potential molecular mechanisms and identified reprogramming driver factor to improve the efficiency of SCNT reprogramming.
终末分化的体细胞可通过体细胞核移植（SCNT）重编程为全能状态。重编程不完全是SCNT胚胎早期发育停滞的主要原因。在我们的研究中，我们发现自噬、内吞作用和凋亡途径在核移植（NT）2细胞期停滞胚胎中未完全激活，而干细胞多能性维持、DNA修复、细胞周期和自噬途径的广泛抑制可能导致NT 4细胞期胚胎停滞。至于NT正常胚胎，观察到发育转录因子（TFs）Id1、Pou6f1、Cited1和Zscan4c的表达发生了显著变化。与仅在NT 2细胞期激活的多能基因Ascl2相比，Nanog、Dppa2和Sall4在NT 2细胞期和4细胞期胚胎的正常发育中都有主要的表达波。此外，Kdm4b/4d和Kdm5b分别被确认为NT 2细胞期和4细胞期胚胎的关键标志物。组蛋白乙酰转移酶Kat8、Elp6和EidI在NT 2细胞期和4细胞期胚胎中共同激活，以促进正常发育。Gadd45a作为关键驱动因子与Tet1和Tet2共同作用，提高NT重编程的效率。综上所述，我们的研究结果为阐明潜在的分子机制提供了重要的理论基础，并确定了重编程驱动因子，以提高SCNT重编程的效率。
