The systematic breaking of left–right body symmetry is a familiar feature of human physiology. In humans and many animals, this process originates with asymmetric fluid flow driven by rotating cilia, occurring in a short-lived embryonic organizing structure termed the node. The very low–Reynolds number fluid mechanics of this system is reviewed; important features include how cilia rotation combines with tilt to produce asymmetric flow, boundary effects, time dependence, and the interpretation of particle tracking experiments. The effect of perturbing cilia length and number is discussed and compared in mouse and zebrafish. Whereas understanding of this process has advanced significantly over the past two decades, there is still no consensus on how flow is converted to asymmetric gene expression, with most research focusing on resolving mechanical versus morphogen sensing. The underlying process may be more subtle, probably involving a combination of these effects, with fluid mechanics playing a central role.

中文翻译：

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胚胎发生中破坏对称性的纤毛驱动流

左右身体对称性的系统性破坏是人类生理学的一个熟悉的特征。在人类和许多动物中，这个过程起源于由旋转纤毛驱动的不对称流体流动，发生在称为节点的短命胚胎组织结构中。回顾了该系统的极低雷诺数流体力学；重要的特征包括纤毛旋转如何与倾斜相结合以产生不对称流动、边界效应、时间依赖性以及对粒子跟踪实验的解释。在小鼠和斑马鱼中讨论和比较了扰动纤毛长度和数量的影响。尽管在过去的二十年中对该过程的理解有了显着进步，但对于如何将流动转化为不对称基因表达仍没有达成共识，大多数研究都集中在解决机械感测与形态原感测上。潜在的过程可能更微妙，可能涉及这些效应的组合，流体力学起着核心作用。