在这项工作中，研究人员展示了节点上不动的纤毛在响应流动时沿背腹轴发生不对称变形。光镊对不动纤毛的机械刺激可诱导靶细胞中钙离子瞬变和Dand5信使RNA (mRNA)的降解。Pkd2通道蛋白优先定位于不动纤毛的背侧，钙离子瞬变优先由指向腹侧的机械刺激诱导。他们的结果揭示了节点上静止纤毛感知流体流动方向的生物物理机制。
据了解，小鼠胚胎腹侧节点上的静止纤毛是感知向左流动的液体所必需的，这打破了身体的左右对称。然而，流量传感机制长期以来一直没有定论。
附：英文原文
Title: Immotile cilia mechanically sense the direction of fluid flow for left-right determination
Author: Takanobu A. Katoh, Toshihiro Omori, Katsutoshi Mizuno, Xiaorei Sai, Katsura Minegishi, Yayoi Ikawa, Hiromi Nishimura, Takeshi Itabashi, Eriko Kajikawa, Sylvain Hiver, Atsuko H. Iwane, Takuji Ishikawa, Yasushi Okada, Takayuki Nishizaka, Hiroshi Hamada
Issue&Volume: 2023-01-06
Abstract: 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 Dand5 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.
DOI: abq8148
Source: https://www.science.org/doi/10.1126/science.abq8148