Self-diploidization of human haploid parthenogenetic embryos through the Rho pathway regulates endomitosis and failed cytokinesis.
Self-diploidization of human haploid parthenogenetic embryos through the Rho pathway regulates endomitosis and failed cytokinesis.
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人类单倍体孤雌胚胎的自二倍化通过 Rho 途径调节细胞内有丝分裂和胞质分裂失败
DOI：
10.1038/s41598-017-04602-y
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发表时间：
2017-06-26
影响因子：
4.6
通讯作者：
Lin G
中科院分区：
文献类型：
--
作者：
Leng L;Ouyang Q;Kong X;Gong F;Lu C;Zhao L;Shi Y;Cheng D;Hu L;Lu G;Lin G
二倍体基因组是哺乳动物正常发育所必需的，因此单倍体孤雌生殖胚胎在植入前发育期间经历频繁的自身二倍体化;然而，其潜在机制尚不清楚。在这项研究中，延时记录显示，人类单倍体单性生殖细胞（HP）通过失败的胞质分裂（FC）和胞内有丝分裂（EM）进行自我二倍体化。HP的FC/EM发生率显著高于正常受精胚胎（26.3%vs.1.6%，P < 0.01; 19.7%vs.0，P < 0.01），且90%以上的FC/EM发生在第1个细胞周期。16、18号染色体和X染色体的原位杂交结果显示，FC/EM的HPs在出现FC/EM后可恢复为二倍体，且FC/EM的HPs囊胚形成率高于non-FC/EM的HPs（18.8%和40.0%vs.15.4%，P > 0.05）。在66.7%的1-细胞期HP中，在正常卵裂的时间期间未观察到沟内移，并且1-细胞期HP的免疫染色和基因表达分析均揭示了调节细胞有丝分裂的Rho途径的几个关键基因的缺失或下调。我们的研究结果表明，自二倍体化的主要机制是Rho通路抑制导致FC/EM在第一个细胞周期中，微调这一信号通路可能有助于产生稳定的单倍体胚胎干细胞生物学研究。
A diploid genome is necessary for normal mammalian development, thus haploid parthenogenetic embryos undergo frequent self-diploidization during preimplantation development; however, the underlying mechanism is unclear. In this study, time-lapse recording revealed that human haploid parthenotes (HPs) undergo self-diploidization via failed cytokinesis (FC) and endomitosis (EM). The frequencies of FC/EM were significantly higher in HPs than in normal fertilized embryos (26.3%vs. 1.6%, P < 0.01; 19.7%vs. 0, P < 0.01), and above 90% of FC/EM occurred at the first cell cycle in HPs. Fluorescentin situhybridization of chromosome 16,18 and X in HPs identified diploid recovery after the appearance of FC/EM, and FC/EM HPs showed improved blastocyst formation compared with non-FC/EM HPs (18.8% and 40.0%vs. 15.4%, P > 0.05). In 66.7% of the 1-cell stage HPs, furrow ingression was not observed during the time for normal cleavage, and both immunostaining and gene expression analysis of 1-cell stage HPs revealed the absence or down-regulation of several key genes of the Rho pathway, which regulates cytomitosis. Our results suggested that the major mechanism for self-diploidization is Rho pathway inhibition leading to FC/EM in the first cell cycle, and fine-tuning of this signalling pathway may help to generate stable haploid embryos for stem cell biology studies.