Combining Laser Microsurgery and Finite Element Modeling to Assess Cell-Level Epithelial Mechanics
Combining Laser Microsurgery and Finite Element Modeling to Assess Cell-Level Epithelial Mechanics
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DOI：
10.1016/j.bpj.2009.09.034
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发表时间：
2009-12-16
影响因子：
3.4
通讯作者：
Brodland, G. Wayne
中科院分区：
文献类型：
--
作者：
Hutson, M. Shane;Veldhuis, J.;Brodland, G. Wayne
利用激光显微外科技术和有限元模拟技术研究了果蝇胚胎背部羊膜的细胞水平机制。羊膜是果蝇胚胎背面的一种重要的形态发生学上皮。在实验中，紧密聚焦的激光消融了一个亚细胞孔(直径1微米)，它干净地穿过了上皮。周围的细胞从伤口处以很大范围的初始反冲速度反冲。这取决于胚胎的发育阶段和亚细胞创伤部位。基本有限元模型很好地再现了初始反冲(高达0.1S)，该模型假定单元内的有效粘度均匀，沿单元-单元边界的张力恒定，以及一个大的、潜在的各向异性远场应力-远远超过单元-边缘张力的应力当量。在S 0.1后，实验反冲显著减慢。这种观察可以通过沿细胞边缘添加粘弹性棒或作为平行于细胞顶膜和基底膜的细小的预应力网来重现。该网格还复制了许多双伤实验，在这些实验中，在单个单元中连续钻出了孔。
Laser microsurgery and finite element modeling are used to determine the cell-level mechanics of the amnioserosa-a morphogenetically crucial epithelium on the dorsal surface of fruit fly embryos (Drosophila melanogaster). In the experiments, a tightly focused laser ablates a subcellular hole (1 mu m in diameter) that passes clean through the epithelium. The surrounding cells recoil from the wound site with a large range of initial recoil velocities. These depend on the embryo's developmental stage and the subcellular wound site. The initial recoil (up to 0.1 s) is well reproduced by a base finite element model, which assumes a uniform effective viscosity inside the cells, a constant tension along each cell-cell boundary, and a large, potentially anisotropic, far-field stress-one that far exceeds the stress equivalent of the cell-edge tensions. After 0.1 s, the experimental recoils slow dramatically. This observation can be reproduced by adding viscoelastic: rods along cell edges or as a fine prestressed mesh parallel to the apical and basal membranes of the cell. The mesh also reproduces a number of double-wounding experiments in which successive holes are drilled in a single cell.