The mechanical anisotropy in a tissue promotes ordering in hexagonal cell packing
The mechanical anisotropy in a tissue promotes ordering in hexagonal cell packing
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DOI：
10.1242/dev.094060
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发表时间：
2013-10
期刊：
影响因子：
4.6
通讯作者：
K. Sugimura;S. Ishihara
中科院分区：
文献类型：
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作者：
K. Sugimura;S. Ishihara
许多上皮组织将细胞堆积成蜂窝状，以支持其结构和功能的完整性。细胞填充几何形状的发育变化已被证明是由细胞之间的机械和生化相互作用调节的；然而，分子和细胞动力学以及组织力学是如何协调实现六边形细胞包装的正确和稳健发展的，这在很大程度上是未知的。在这里，通过结合机械和遗传扰动以及实时成像和贝叶斯力推断，我们研究了机械力如何调节细胞动力学，以获得果蝇蛹翅膀的六边形细胞结构。我们表明，组织应力是面向近端远端轴由外力作用在机翼上。细胞对组织拉伸作出反应，并使细胞接触面与组织拉伸方向一致，从而在细胞群体水平上稳定了细胞内部连接张力与外源力之间的平衡。因此，在二维上皮片的拓扑约束下，六边形阵列方向的不匹配被抑制，允许六边形细胞模式更快地松弛。因此，我们的研究结果确定了组织中机械各向异性促进细胞填充几何有序的机制。
Many epithelial tissues pack cells into a honeycomb pattern to support their structural and functional integrity. Developmental changes in cell packing geometry have been shown to be regulated by both mechanical and biochemical interactions between cells; however, it is largely unknown how molecular and cellular dynamics and tissue mechanics are orchestrated to realize the correct and robust development of hexagonal cell packing. Here, by combining mechanical and genetic perturbations along with live imaging and Bayesian force inference, we investigate how mechanical forces regulate cellular dynamics to attain a hexagonal cell configuration in the Drosophila pupal wing. We show that tissue stress is oriented towards the proximal-distal axis by extrinsic forces acting on the wing. Cells respond to tissue stretching and orient cell contact surfaces with the stretching direction of the tissue, thereby stabilizing the balance between the intrinsic cell junction tension and the extrinsic force at the cell-population level. Consequently, under topological constraints of the two-dimensional epithelial sheet, mismatches in the orientation of hexagonal arrays are suppressed, allowing more rapid relaxation to the hexagonal cell pattern. Thus, our results identify the mechanism through which the mechanical anisotropy in a tissue promotes ordering in cell packing geometry.