Totipotent-Like Cell-Based Embryo Model Recapitulating Mouse Embryogenesis from Pre-Implantation to Gastrulation [scRNA-Seq]

The development of stem-cell-derived models of mammalian embryogenesis has provided invaluable tools for investigating embryo development. However, constructing embryo models that can continuously recapitulate the full developmental trajectory, from zygotic genome activation (ZGA) to gastrulation, remains a major challenge. Here, we developed a new chemical cocktail to induce totipotent-like cells with robust proliferation ability, and leveraged these cells to establish a stepwise protocol to generate a continuous embryo model. This model sequentially mimics mouse embryogenesis from embryonic day 1.5 to 7.5. It recapitulates key developmental milestones, including ZGA in 2-cell embryos, the diversification of embryonic and extraembryonic lineages from 4-cell to 64-cell stages, the formation of blastocysts, and the subsequent development into post-implantation egg cylinders. Notably, these structures can undergo gastrulation, as evidenced by primitive streak formation and the subsequent emergence of several hallmarks of early organogenesis. Our study opens new avenues for modeling mammalian embryogenesis in vitro. Overall design: Total of 8 scRNAseq samples were analyzed, which include s1, s2, s3, s4, s4-2 (a new batch of s4), s5, s7 and s8.

干细胞来源的哺乳动物胚胎发生模型的构建，为胚胎发育的机制研究提供了不可或缺的实验工具。然而，构建能够连续重现从合子基因组激活（zygotic genome activation, ZGA）到原肠胚形成的完整发育轨迹的胚胎模型，仍是一项重大挑战。本研究开发了一种新型化学诱导配方，用以诱导具备强增殖能力的类全能性细胞，并依托此类细胞建立了一套分步式方案，以构建可连续发育的胚胎模型。该模型可依次模拟小鼠胚胎发育从胚胎第1.5天至第7.5天的全过程，重现了多项关键发育节点：包括2细胞胚胎阶段的合子基因组激活、4细胞至64细胞阶段胚胎谱系与胚外谱系的分化、囊胚的形成，以及后续发育为植入后卵柱结构。值得注意的是，此类结构可发生原肠胚形成过程，表现为原条的形成，以及后续早期器官发生的多项标志性事件的出现。本研究为体外构建哺乳动物胚胎发生模型开辟了全新的研究路径。实验整体设计：本研究共分析了8个单细胞RNA测序（single-cell RNA sequencing, scRNAseq）样本，涵盖s1、s2、s3、s4、s4-2（s4的新批次样本）、s5、s7及s8。