Spatial molecular anatomy of germ layers in the gastrulating Cynomolgus monkey embryo-Supplemental Materials

During mammalian embryogenesis, spatial regulation of gene expression and cell signaling are functionally coupled with lineage specification, patterning of tissue progenitors and germ layer morphogenesis. While the mouse model has been instrumental for understanding mammalian development, comparatively little is known about human and non-human primate gastrulation due to the restriction of both technical and ethical issues. Here, we present a spatial and temporal survey of the molecular dynamics of cell types populating the non-human primate embryos during gastrulation. We reconstructed three-dimensional digital models from serial sections of Cynomolgus monkey (Macaca fascicularis) gastrulating embryos at 1-day temporal resolution from E17 to E21. Spatial transcriptomics identifies gene expression profiles unique to the germ layers. Cross-species comparison reveals a developmental coordinate of germ layer segregation between mouse and primates, and species-specific transcription programs during gastrulation. These findings offer insights into evolutionarily conserved and divergent processes during mammalian gastrulation. This Supplemental Materials containing Table S1-7, Supplementary file 1-10 and Supplementary video 1. They are also available at our website: http://sop.ccla.ac.cn.在哺乳动物胚胎发生过程中，基因表达的空间调控与细胞信号传导在功能上与谱系特化、组织祖细胞模式形成以及胚层形态发生紧密耦合。尽管小鼠模型对于解析哺乳动物发育进程发挥了至关重要的作用，但由于技术与伦理层面的双重限制，目前学界对人类以及非人类灵长类动物的原肠胚形成过程的认知仍相对匮乏。本研究对非人类灵长类胚胎原肠胚形成阶段的各类细胞类型的分子动态变化开展了时空层面的系统性分析。我们针对食蟹猴（Macaca fascicularis）原肠胚形成阶段的胚胎连续切片，以1天的时间分辨率从胚胎期E17至E21重建了三维数字化模型。空间转录组学（Spatial transcriptomics）技术鉴定出了各胚层特有的基因表达谱。跨物种比较分析揭示了小鼠与灵长类动物之间胚层分离的发育调控轴，以及原肠胚形成过程中物种特异性的转录程序。上述研究结果为解析哺乳动物原肠胚形成过程中进化保守与物种分歧的发育机制提供了新的见解。 本研究的补充材料包含表S1-7、补充文件1-10以及补充视频1，相关资源亦可通过本团队的官方网站http://sop.ccla.ac.cn获取。