Planar polarization of node cells determines the rotational axis of node cilia
Planar polarization of node cells determines the rotational axis of node cilia
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DOI：
10.1038/ncb2020
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发表时间：
2010-02-01
影响因子：
21.3
通讯作者：
Hamada, Hiroshi
中科院分区：
文献类型：
--
作者：
Hashimoto, Masakazu;Shinohara, Kyosuke;Hamada, Hiroshi
节点纤毛的旋转运动会在小鼠胚胎中产生向左的液流(1)，因为纤毛向后倾斜(2,3)。然而，目前尚不清楚前后信息如何转化为节点纤毛的后倾斜。在这里，我们发现节点纤毛的基体最初位于中央，但随后逐渐向节点细胞的后侧移动。发现缺乏 Dvl 基因的复合突变小鼠的基体定位和单向流动受到损害。虽然基体通常位于 Wnt3a(-/-) 胚胎的节点细胞中，但对非经典 Wnt 信号通路的一个组成部分 Rac1 的抑制会损害野生型胚胎中基体的极化定位。发现Dvl2和Dvl3蛋白定位于结节细胞的顶端侧，并且在基体后定位之前它们的位置极化至细胞的后侧。这些结果表明，基体的后定位（为结纤毛提供后倾斜）是由非规范 Wnt 信号传导介导的平面偏振决定的。
Rotational movement of the node cilia generates a leftward fluid flow in the mouse embryo(1) because the cilia are posteriorly tilted(2,3). However, it is not known how anterior-posterior information is translated into the posterior tilt of the node cilia. Here, we show that the basal body of node cilia is initially positioned centrally but then gradually shifts toward the posterior side of the node cells. Positioning of the basal body and unidirectional flow were found to be impaired in compound mutant mice lacking Dvl genes. Whereas the basal body was normally positioned in the node cells of Wnt3a(-/-) embryos, inhibition of Rac1, a component of the noncanonical Wnt signalling pathway, impaired the polarized localization of the basal body in wild-type embryos. Dvl2 and Dvl3 proteins were found to be localized to the apical side of the node cells, and their location was polarized to the posterior side of the cells before the posterior positioning of the basal body. These results suggest that posterior positioning of the basal body, which provides the posterior tilt to node cilia, is determined by planar polarization mediated by noncanonical Wnt signalling.