Elastohydrodynamic phase-lock in two rotating cilia
Elastohydrodynamic phase-lock in two rotating cilia
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DOI：
10.1299/jbse.17-00467
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发表时间：
2017
影响因子：
--
通讯作者：
T. Omori;Mingming Lu;T. Ishikawa
中科院分区：
文献类型：
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作者：
T. Omori;Mingming Lu;T. Ishikawa
确定身体平面的左右不对称是在早期胚胎中实现的。在4-6个体节时期，腹中线表面可观察到一种称为结节的空腔结构，其中有数百根纤毛旋转。结节纤毛通常向后倾斜，并沿顺时针方向旋转，导致结节内产生向左的flow。这种向左的flow触发了左特异性fic基因的表达，而fl的uid机制在左右对称破缺中发挥了作用。为了了解纤毛驱动的结节flow，有必要确定旋转纤毛之间的水动力相互作用，因为纤毛运动通过fluid运动相互作用。在这项研究中，我们数值研究了两个旋转纤毛的弹性流体动力学同步，以及flowfield。纤毛运动由细胞骨架弹性力、运动蛋白诱导的激活力和fl粘滞力的平衡决定。根据几何离合器假设，旋转纤毛的频率由弯曲曲率控制。由于流体的相互作用，两纤毛的弯曲变形是时间相关的，旋转被fi锁定在反相中，而与相对位置和初始相差无关。通过锁定反相，平均推进flow速率变得比同相拍打大2-3倍。本研究的结果为理解纤毛驱动的结节flOW奠定了基础。
Determination of left-right asymmetry of the body plan is achieved in the early embryo. At the 4-6 somite stage, a cavity structure, called a node, is observed in the ventral midline surface, in which hundreds of cilia rotate. Nodal cilia are typically tilted toward the posterior and rotate in the clockwise direction, resulting in the generation of leftward flow in the node. Such leftward flow acts as a trigger of left-specific gene expression, and fluid mechanics plays a role in left-right symmetry breaking. To understand the cilia-driven nodal flow, it is necessary to deter-mine the hydrodynamic interactions among rotating cilia, as ciliary motions interact with each other through fluid motion. In this study, we numerically investigated the elastohydrodynamic synchronization of two rotating cilia, as well as the flow field. The ciliary motion was determined by the balance of cytoskeletal elastic force, motor protein-induced active force, and fluid viscous force. According to the geometric clutch hypothesis, the frequency of rotating cilia is controlled by the bending curvature. Owing to hydrodynamic interactions, bending deforma-tions of two cilia become time-dependent, and the rotation is finally locked in anti-phase regardless of the relative position and initial phase di ff erence. By locking in the reverse phase, the average propulsion flow rate becomes 2-3 times larger than in-phase beating. The results of this study form a basis for understanding cilium-driven nodal flow.