Developmental Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany.
Friedrich-Schiller-Universität Jena, Institut für Zoologie und Evolutionsforschung mit Phyletischem Museum, Ernst-Haeckel-Haus und Biologiedidaktik, 07743 Jena, Germany.
Science. 2021 Nov 5;374(6568):717-723. doi: 10.1126/science.abj2949. Epub 2021 Nov 4.
The evolutionary origin of metazoan cell types such as neurons and muscles is not known. Using whole-body single-cell RNA sequencing in a sponge, an animal without nervous system and musculature, we identified 18 distinct cell types. These include nitric oxide–sensitive contractile pinacocytes, amoeboid phagocytes, and secretory neuroid cells that reside in close contact with digestive choanocytes that express scaffolding and receptor proteins. Visualizing neuroid cells by correlative x-ray and electron microscopy revealed secretory vesicles and cellular projections enwrapping choanocyte microvilli and cilia. Our data show a communication system that is organized around sponge digestive chambers, using conserved modules that became incorporated into the pre- and postsynapse in the nervous systems of other animals.
后生动物细胞类型（如神经元和肌肉）的进化起源尚不清楚。通过对一种没有神经系统和肌肉组织的海绵动物进行全身体单细胞 RNA 测序，我们鉴定出了 18 种不同的细胞类型。这些细胞类型包括对一氧化氮敏感的可收缩足杯细胞、阿米巴样吞噬细胞和分泌神经细胞，它们与表达支架和受体蛋白的消化领细胞密切接触。通过对神经细胞进行相关的 X 射线和电子显微镜观察，发现了分泌小泡和细胞突起，包裹着领细胞的微绒毛和纤毛。我们的数据显示了一个围绕着海绵消化腔组织的通讯系统，使用了保守的模块，这些模块在其他动物的神经系统中成为了前突触和后突触的一部分。
