Two rotating cilia in the node cavity are sufficient to break left-right symmetry in the mouse embryo
Two rotating cilia in the node cavity are sufficient to break left-right symmetry in the mouse embryo
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DOI：
10.1038/ncomms1624
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发表时间：
2012-01-01
影响因子：
16.6
通讯作者：
Hamada, Hiroshi
中科院分区：
文献类型：
--
作者：
Shinohara, Kyosuke;Kawasumi, Aiko;Hamada, Hiroshi
小鼠胚胎左右不对称性的确定是通过在结腔中的微流体流动（结流）来实现的，所述微流体流动（结流）是由结中200-300个纤毛的顺时针旋转运动产生的。节点流的精确作用以及左右确定的鲁棒读出需要多少流输入仍然是未知的。在这里，我们表明，由两个旋转纤毛产生的局部湍流足以打破左右对称。定量分析的流体流动和纤毛旋转的节点的小鼠胚胎表明，左右不对称已经建立在几个小时内开始旋转后，由一个子集的节点纤毛。对各种纤毛突变小鼠的研究表明，两个旋转纤毛足以启动左右不对称基因表达。我们的研究结果表明，存在一个高度敏感的系统中的节点，能够感测到一个非常弱的单向流，并可能有利于一个模型，其中的流量被感知为机械力。
Determination of left-right asymmetry in mouse embryos is achieved by a leftward fluid flow (nodal flow) in the node cavity that is generated by clockwise rotational movement of 200-300 cilia in the node. The precise action of nodal flow and how much flow input is required for the robust read-out of left-right determination remains unknown. Here we show that a local leftward flow generated by as few as two rotating cilia is sufficient to break left-right symmetry. Quantitative analysis of fluid flow and ciliary rotation in the node of mouse embryos shows that left-right asymmetry is already established within a few hours after the onset of rotation by a subset of nodal cilia. Examination of various ciliary mutant mice shows that two rotating cilia are sufficient to initiate left-right asymmetric gene expression. Our results suggest the existence of a highly sensitive system in the node that is able to sense an extremely weak unidirectional flow, and may favour a model in which the flow is sensed as a mechanical force.