Katoh Takanobu A, Omori Toshihiro, Mizuno Katsutoshi, Sai Xiaorei, Minegishi Katsura, Ikawa Yayoi, Nishimura Hiromi, Itabashi Takeshi, Kajikawa Eriko, Hiver Sylvain, Iwane Atsuko H, Ishikawa Takuji, Okada Yasushi, Nishizaka Takayuki, Hamada Hiroshi
Laboratory for Organismal Patterning, RIKEN Center for Biosystems Dynamics Research, Kobe, Hyogo, Japan.
Department of Physics, Faculty of Science, Gakushuin University, Toshima-ku, Tokyo, Japan.
Science. 2023 Jan 6;379(6627):66-71. doi: 10.1126/science.abq8148. Epub 2023 Jan 5.
Immotile cilia at the ventral node of mouse embryos are required for sensing leftward fluid flow that breaks left-right symmetry of the body. However, the flow-sensing mechanism has long remained elusive. In this work, we show that immotile cilia at the node undergo asymmetric deformation along the dorsoventral axis in response to the flow. Application of mechanical stimuli to immotile cilia by optical tweezers induced calcium ion transients and degradation of messenger RNA (mRNA) in the targeted cells. The Pkd2 channel protein was preferentially localized to the dorsal side of immotile cilia, and calcium ion transients were preferentially induced by mechanical stimuli directed toward the ventral side. Our results uncover the biophysical mechanism by which immotile cilia at the node sense the direction of fluid flow.
小鼠胚胎腹侧节点处的不动纤毛对于感知打破身体左右对称的向左的液体流动是必需的。然而，流体感知机制长期以来一直难以捉摸。在这项工作中，我们表明节点处的不动纤毛会响应流动而沿背腹轴发生不对称变形。通过光镊对不动纤毛施加机械刺激会诱导靶向细胞中的钙离子瞬变和信使核糖核酸（mRNA）降解。多囊蛋白2（Pkd2）通道蛋白优先定位于不动纤毛的背侧，并且钙离子瞬变优先由指向腹侧的机械刺激诱导。我们的结果揭示了节点处的不动纤毛感知流体流动方向的生物物理机制。
