Developmental Genetics Group, Graduate School of Frontier Biosciences, Osaka University, 1-3 Yamada-oka, Suita, 565-0871 Osaka, Japan.
Science. 2012 Oct 12;338(6104):226-31. doi: 10.1126/science.1222538. Epub 2012 Sep 13.
Unidirectional fluid flow plays an essential role in the breaking of left-right (L-R) symmetry in mouse embryos, but it has remained unclear how the flow is sensed by the embryo. We report that the Ca(2+) channel Polycystin-2 (Pkd2) is required specifically in the perinodal crown cells for sensing the nodal flow. Examination of mutant forms of Pkd2 shows that the ciliary localization of Pkd2 is essential for correct L-R patterning. Whereas Kif3a mutant embryos, which lack all cilia, failed to respond to an artificial flow, restoration of primary cilia in crown cells rescued the response to the flow. Our results thus suggest that nodal flow is sensed in a manner dependent on Pkd2 by the cilia of crown cells located at the edge of the node.
单向流体流动在小鼠胚胎左右（L-R）对称性的打破中起着至关重要的作用，但目前尚不清楚胚胎如何感知流动。我们报告称，多囊蛋白-2（Pkd2）钙通道专门在节结冠细胞中感应节结流动。对 Pkd2 突变体形式的检查表明，Pkd2 的纤毛定位对于正确的 L-R 模式至关重要。而缺乏所有纤毛的 Kif3a 突变体胚胎则无法对人工流动做出反应，但是在冠细胞中恢复初级纤毛可以挽救对流动的反应。因此，我们的结果表明，节结边缘的冠细胞中的纤毛以依赖于 Pkd2 的方式来感应节结流动。
