School of Biosciences, University of Nottingham, LE12 5RD, UK.
Theriogenology. 2020 Jul 1;150:55-58. doi: 10.1016/j.theriogenology.2020.01.062. Epub 2020 Jan 30.
The zygote undergoes five cell divisions prior to the first signs of lineage segregation. Blastocyst formation requires segregation of the trophectoderm, needed for implantation, and the inner cell mass, which differentiate towards the major lineages of the fetus. This process is broadly conserved in mammals, however, in recent years investigations using high throughput single cell transcriptomics have provided new insights on the gene regulatory networks and epigenetic mechanisms controlling these processes in different species, highlighting novel unique evolutionary adaptations. Although analysis of single cell datasets is inherently challenging due to stochastic gene expression in single cells, continuous development of novel computational tools have contributed to improving the quality of these datasets. Single cell -omics provides detailed information on discrete cellular states, and when combined with spatial transcriptomics it can inform on the relationship between cellular compartments and fate determination. This technology has recently been used to shed new light into the progression of lineage segregation, establishment of pluripotency, epigenetic regulation and signalling pathways participating in mammalian pre-gastrulation development. The adoption of these new technologies for generating high-resolution maps of embryogenesis will readily translate into biotechnological applications that will have significant impact in livestock production.
受精卵在出现谱系分离的第一个迹象之前经历五次细胞分裂。囊胚形成需要滋养外胚层的分离，滋养外胚层是植入所必需的，以及内细胞团，内细胞团向胎儿的主要谱系分化。这个过程在哺乳动物中广泛保守，然而，近年来使用高通量单细胞转录组学的研究为控制这些过程的基因调控网络和表观遗传机制提供了新的见解，突出了新的独特的进化适应。尽管由于单细胞中随机基因表达，单细胞数据集的分析本质上具有挑战性，但新型计算工具的不断发展有助于提高这些数据集的质量。单细胞组学提供了关于离散细胞状态的详细信息，当与空间转录组学结合使用时，它可以提供关于细胞区室之间的关系和命运决定的信息。这项技术最近被用于揭示谱系分离、多能性建立、参与哺乳动物原肠胚发育的表观遗传调控和信号通路的进展。这些新技术在生成胚胎发生高分辨率图谱方面的应用将很容易转化为生物技术应用，这将对畜牧业生产产生重大影响。
