Fu Penghui, Zhang Du, Yang Chunyan, Yuan Xiang, Luo Xier, Zheng Haiying, Deng Yanfei, Liu Qingyou, Cui Kuiqing, Gao Fei, Shi Deshun
State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources & Guangxi Key Laboratory of Animal Breeding and Disease Control, Guangxi University, Nanning, 530004, China.
College of Animal Science and Technology, Southwest University, Chongqing, 402460, China.
J Anim Sci Biotechnol. 2023 Jul 11;14(1):94. doi: 10.1186/s40104-023-00894-5.
During mammalian pre-implantation embryonic development (PED), the process of maternal-to-zygote transition (MZT) is well orchestrated by epigenetic modification and gene sequential expression, and it is related to the embryonic genome activation (EGA). During MZT, the embryos are sensitive to the environment and easy to arrest at this stage in vitro. However, the timing and regulation mechanism of EGA in buffaloes remain obscure.
Buffalo pre-implantation embryos were subjected to trace cell based RNA-seq and whole-genome bisulfite sequencing (WGBS) to draw landscapes of transcription and DNA-methylation. Four typical developmental steps were classified during buffalo PED. Buffalo major EGA was identified at the 16-cell stage by the comprehensive analysis of gene expression and DNA methylation dynamics. By weighted gene co-expression network analysis, stage-specific modules were identified during buffalo maternal-to-zygotic transition, and key signaling pathways and biological process events were further revealed. Programmed and continuous activation of these pathways was necessary for success of buffalo EGA. In addition, the hub gene, CDK1, was identified to play a critical role in buffalo EGA.
Our study provides a landscape of transcription and DNA methylation in buffalo PED and reveals deeply the molecular mechanism of the buffalo EGA and genetic programming during buffalo MZT. It will lay a foundation for improving the in vitro development of buffalo embryos.
在哺乳动物植入前胚胎发育（PED）过程中，母型向合子型转变（MZT）过程由表观遗传修饰和基因顺序表达精心编排，且与胚胎基因组激活（EGA）相关。在MZT期间，胚胎对环境敏感，在体外很容易在此阶段停滞。然而，水牛中EGA的时间和调控机制仍不清楚。
对水牛植入前胚胎进行微量细胞RNA测序和全基因组亚硫酸氢盐测序（WGBS），以绘制转录和DNA甲基化图谱。在水牛PED过程中划分出四个典型的发育阶段。通过对基因表达和DNA甲基化动态的综合分析，确定水牛主要的EGA发生在16细胞阶段。通过加权基因共表达网络分析，在水牛母型向合子型转变过程中鉴定出阶段特异性模块，并进一步揭示了关键信号通路和生物学过程事件。这些通路的程序性和持续激活是水牛EGA成功的必要条件。此外，鉴定出枢纽基因CDK1在水牛EGA中起关键作用。
我们的研究提供了水牛PED中转录和DNA甲基化图谱，并深入揭示了水牛EGA的分子机制以及水牛MZT期间的基因编程。它将为改善水牛胚胎的体外发育奠定基础。
