蜘蛛是5亿年前与其他节肢动物不同的螯合物。蜘蛛胚胎发生的研究,特别是使用普通的家蜘蛛Parasteatodatepidariorum的研究,为理解动物发育的进化做出了重要贡献,包括轴的形成,分割,和图案。然而,我们对构建蜘蛛胚胎的细胞缺乏了解,他们的基因表达谱和命运。单细胞转录组学分析在描述一系列动物中这些复杂的细胞遗传学景观方面具有革命性。因此,我们在第7、8和9阶段进行了假单胞菌胚胎的单细胞RNA测序,其中包括身体计划的建立和模式,以及许多组织和器官的初始分化。我们确定了20个细胞簇,从18.5k细胞,以许多发育工具包基因为标志,以及大量以前没有研究过的基因。我们发现了细胞周期转录特征的差异,暗示不同的增殖动力学,这与内胚层和一些中胚层簇之间的区别有关,与外胚层簇相比。我们确定了许多Hox基因作为细胞簇的标记,和Hox基因同源物通常存在于不同的簇中。这提供了额外的证据,证明了这些重要的发育基因在整个基因组复制后的亚和/或新功能化在一个蜘蛛祖先(蜘蛛,蝎子,和相关订单)。我们还检查了每个簇的标记基因的空间表达,以生成这些胚胎阶段的综合细胞图谱。这揭示了对头部模式的细胞基础和遗传调控的新见解,造血,肢体发育,肠道发育,和后验分割。该地图集将作为未来分析蜘蛛细胞规格和命运的平台,并以细胞分辨率研究动物之间这些过程的进化。
Spiders are a diverse order of chelicerates that diverged from other arthropods over 500 million years ago. Research on spider embryogenesis, particularly studies using the common house spider Parasteatoda tepidariorum, has made important contributions to understanding the evolution of animal development, including axis formation, segmentation, and patterning. However, we lack knowledge about the cells that build spider embryos, their gene expression profiles and fate. Single-cell transcriptomic analyses have been revolutionary in describing these complex landscapes of cellular genetics in a range of animals. Therefore, we carried out single-cell RNA sequencing of P. tepidariorum embryos at stages 7, 8 and 9, which encompass the establishment and patterning of the body plan, and initial differentiation of many tissues and organs. We identified 20 cell clusters, from 18.5 k cells, which were marked by many developmental toolkit genes, as well as a plethora of genes not previously investigated. We found differences in the cell cycle transcriptional signatures, suggestive of different proliferation dynamics, which related to distinctions between endodermal and some mesodermal clusters, compared with ectodermal clusters. We identified many Hox genes as markers of cell clusters, and Hox gene ohnologs were often present in different clusters. This provided additional evidence of sub- and/or neo-functionalisation of these important developmental genes after the whole genome duplication in an arachnopulmonate ancestor (spiders, scorpions, and related orders). We also examined the spatial expression of marker genes for each cluster to generate a comprehensive cell atlas of these embryonic stages. This revealed new insights into the cellular basis and genetic regulation of head patterning, hematopoiesis, limb development, gut development, and posterior segmentation. This atlas will serve as a platform for future analysis of spider cell specification and fate, and studying the evolution of these processes among animals at cellular resolution.