Institute of Genetics, Technische Universität Dresden, 01062 Dresden, Germany.
Institute of Genetics, Technische Universität Dresden, 01062 Dresden, Germany
Development. 2020 Dec 4;147(23):dev194316. doi: 10.1242/dev.194316.
The folding of epithelial sheets is important for tissues, organs and embryos to attain their proper shapes. Epithelial folding requires subcellular modulations of mechanical forces in cells. Fold formation has mainly been attributed to mechanical force generation at apical cell sides, but several studies indicate a role of mechanical tension at lateral cell sides in this process. However, whether lateral tension increase is sufficient to drive epithelial folding remains unclear. Here, we have used optogenetics to locally increase mechanical force generation at apical, lateral or basal sides of epithelial wing disc cells, an important model for studying morphogenesis. We show that optogenetic recruitment of RhoGEF2 to apical, lateral or basal cell sides leads to local accumulation of F-actin and increase in mechanical tension. Increased lateral tension, but not increased apical or basal tension, results in sizeable fold formation. Our results stress the diversification of folding mechanisms between different tissues and highlight the importance of lateral tension increase for epithelial folding.
上皮片层的折叠对于组织、器官和胚胎获得其适当的形状非常重要。上皮折叠需要细胞内机械力的亚细胞调节。褶皱的形成主要归因于顶端细胞侧的机械力产生，但有几项研究表明在这个过程中，细胞侧的机械张力也起着作用。然而，侧向张力的增加是否足以驱动上皮折叠仍然不清楚。在这里，我们使用光遗传学在翅膀盘细胞的顶端、侧面或底部局部增加机械力的产生，翅膀盘细胞是研究形态发生的重要模型。我们表明，光遗传学募集 RhoGEF2 到顶端、侧面或底部细胞侧会导致 F-肌动蛋白的局部积累和机械张力的增加。增加的侧向张力，而不是增加的顶端或底部张力，导致明显的褶皱形成。我们的结果强调了不同组织之间折叠机制的多样化，并强调了侧向张力增加对于上皮折叠的重要性。
