Université Côte d'Azur, CNRS, Inserm, iBV, Nice, France.
Université Côte d'Azur, CNRS, Inserm, iBV, Nice, France.
Dev Cell. 2021 May 17;56(10):1469-1483.e5. doi: 10.1016/j.devcel.2021.04.003. Epub 2021 Apr 22.
During embryo development, tissues often undergo multiple concomitant changes in shape. It is unclear which signaling pathways and cellular mechanisms are responsible for multiple simultaneous tissue shape transformations. We focus on the process of concomitant tissue folding and extension that is key during gastrulation and neurulation. We use the Drosophila embryo as model system and focus on the process of mesoderm invagination. Here, we show that the prospective mesoderm simultaneously folds and extends. We report that mesoderm cells, under the control of anterior-posterior and dorsal-ventral gene patterning synergy, establish two sets of adherens junctions at different apical-basal positions with specialized functions: while apical junctions drive apical constriction initiating tissue bending, lateral junctions concomitantly drive polarized cell intercalation, resulting in tissue convergence-extension. Thus, epithelial cells devise multiple specialized junctional sets that drive composite morphogenetic processes under the synergistic control of apparently orthogonal signaling sources.
在胚胎发育过程中，组织经常会发生多种伴随的形状变化。目前尚不清楚哪些信号通路和细胞机制负责多种同时发生的组织形状转变。我们专注于伴随的组织折叠和延伸过程，这是原肠胚形成和神经管形成过程中的关键步骤。我们使用果蝇胚胎作为模型系统，专注于中胚层内陷的过程。在这里，我们表明，中胚层细胞同时折叠和延伸。我们报告说，中胚层细胞在前后和背腹基因模式协同作用的控制下，在不同的顶端-基底位置建立了两组具有特殊功能的黏附连接：虽然顶端连接驱动起始组织弯曲的顶端收缩，但侧连接同时驱动极化细胞的插入，导致组织汇聚-延伸。因此，上皮细胞设计了多个专门的连接组，在明显正交的信号源协同控制下，驱动复合形态发生过程。
