Inoue Yasuhiro, Watanabe Tadashi, Okuda Satoru, Adachi Taiji
Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto, 606-8507, Japan.
RIKEN Center for Developmental Biology, Kobe, 650-0047, Japan.
Dev Growth Differ. 2017 Jun;59(5):444-454. doi: 10.1111/dgd.12374. Epub 2017 Jul 13.
Epithelial invagination is one of the fundamental deformation modes during morphogenesis, and is essential for deriving the three-dimensional shapes of organs from a flat epithelial sheet. Invagination occurs in an orderly manner according to the spatial pattern of the contractile cells; however, it remains elusive how tissue deformation can be caused by cellular activity in the patterned region. In this study, we investigated the mechanical role of the spatial patterns of the contractile cells in invagination of growing tissue using multicellular dynamics simulations. We found that cell proliferation and apical constriction were responsible for expanding the degree of tissue deformation and determining the location of the deformation, respectively. The direction of invagination depended on the spatial pattern of the contractile cells. Further, comparing the simulation results of surface and line contractions as possible modes of apical constriction, we found that the direction of invagination differed between these two modes even if the spatial pattern was the same. These results indicate that the buckling of the epithelial cell sheet caused by cell proliferation causes the invagination, with the direction and location determined by the configuration of the wedge-shaped cells given by the spatial pattern of the contractile cells.
上皮内陷是形态发生过程中的基本变形模式之一，对于从扁平上皮片衍生出器官的三维形状至关重要。内陷根据收缩细胞的空间模式有序发生；然而，组织变形如何由图案化区域中的细胞活动引起仍然不清楚。在本研究中，我们使用多细胞动力学模拟研究了收缩细胞的空间模式在生长组织内陷中的力学作用。我们发现细胞增殖和顶端收缩分别负责扩大组织变形程度和确定变形位置。内陷方向取决于收缩细胞的空间模式。此外，比较表面收缩和线收缩作为顶端收缩可能模式的模拟结果，我们发现即使空间模式相同，这两种模式之间的内陷方向也不同。这些结果表明，细胞增殖引起的上皮细胞片的屈曲导致内陷，其方向和位置由收缩细胞的空间模式给出的楔形细胞的构型决定。
