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Abstract：
The paramount importance of mechanical forces in morphogenesis and embryogenesis is widely recognized, but understanding the mechanism at the cellular and molecular level remains challenging. Because of its simple internal organization, Caenorhabditis elegans is a rewarding system of study. As demonstrated experimentally, after an initial period of steady elongation driven by the actomyosin network, muscle contractions operate a quasi-periodic sequence of bending, rotation, and torsion, that leads to the final fourfold size of the embryos before hatching. How actomyosin and muscles contribute to embryonic elongation is investigated here theoretically. A filamentary elastic model that converts stimuli generated by biochemical signals in the tissue into driving forces, explains embryonic deformation under actin bundles and muscle activity, and dictates mechanisms of late elongation based on the effects of energy conversion and dissipation. We quantify this dynamic transformation by stretches applied to a cylindrical structure that mimics the body shape in finite elasticity, obtaining good agreement and understanding of both wild-type and mutant embryos at all stages.
摘要：
机械力在形态发生和胚胎发生中的重要性已得到广泛认可。但是在细胞和分子水平上理解机制仍然具有挑战性。由于其简单的内部组织，秀丽隐杆线虫是一种有益的研究系统。如实验证明，在由肌动球蛋白网络驱动的稳定伸长的初始阶段之后，肌肉收缩操作一个准周期性的弯曲序列，旋转,和扭转，这导致孵化前胚胎的最终大小为四倍。这里从理论上研究了肌动球蛋白和肌肉如何促进胚胎伸长。一种丝状弹性模型，将组织中生化信号产生的刺激转化为驱动力，解释了肌动蛋白束和肌肉活动下的胚胎变形，并根据能量转换和耗散的影响决定了延迟伸长的机制。我们通过应用于圆柱形结构的拉伸来量化这种动态转换，该结构以有限的弹性模拟身体形状，在所有阶段对野生型和突变胚胎都有很好的一致性和理解。
