CRBM, Université de Montpellier, CNRS, 34293 Montpellier, France.
Virtual Plants, Université de Montpellier, CIRAD, INRA, Inria, 34095 Montpellier, France.
Science. 2020 Jul 10;369(6500). doi: 10.1126/science.aar5663.
Marine invertebrate ascidians display embryonic reproducibility: Their early embryonic cell lineages are considered invariant and are conserved between distantly related species, despite rapid genomic divergence. Here, we address the drivers of this reproducibility. We used light-sheet imaging and automated cell segmentation and tracking procedures to systematically quantify the behavior of individual cells every 2 minutes during embryogenesis. Interindividual reproducibility was observed down to the area of individual cell contacts. We found tight links between the reproducibility of embryonic geometries and asymmetric cell divisions, controlled by differential sister cell inductions. We combined modeling and experimental manipulations to show that the area of contact between signaling and responding cells is a key determinant of cell communication. Our work establishes the geometric control of embryonic inductions as an alternative to classical morphogen gradients and suggests that the range of cell signaling sets the scale at which embryonic reproducibility is observed.
尽管基因组快速分化，但它们的早期胚胎细胞谱系被认为是不变的，并且在远缘物种之间是保守的。在这里，我们探讨了这种再现性的驱动因素。我们使用光片成像和自动细胞分割和跟踪程序，在胚胎发生过程中每 2 分钟系统地定量单个细胞的行为。个体间的再现性可以一直观察到单个细胞接触的区域。我们发现胚胎几何形状的再现性与不对称细胞分裂之间存在紧密联系，这是由不同姐妹细胞诱导控制的。我们结合了建模和实验操作，表明信号和反应细胞之间的接触面积是细胞通讯的关键决定因素。我们的工作确立了胚胎诱导的几何控制作为经典形态发生梯度的替代方案，并表明细胞信号传递的范围决定了胚胎再现性观察的规模。
