Data from: Dynamic curvature regulation accounts for the symmetric and asymmetric beats of Chlamydomonas flagella

Cilia and flagella are model systems for studying how mechanical forces control morphology. The periodic bending motion of cilia and flagella is thought to arise from mechanical feedback: dynein motors generate sliding forces that bend the flagellum, and bending leads to deformations and stresses, which feed back and regulate the motors. Three alternative feedback mechanisms have been proposed: regulation by the sliding forces, regulation by the curvature of the flagellum, and regulation by the normal forces that deform the cross-section of the flagellum. In this work, we combined theoretical and experimental approaches to show that the curvature control mechanism is the one that accords best with the bending waveforms of Chlamydomonas flagella. We make the surprising prediction that the motors respond to the time derivative of curvature, rather than curvature itself, hinting at an adaptation mechanism controlling the flagellar beat.纤毛（Cilia）与鞭毛（flagella）是研究机械力如何调控形态的经典模型系统。目前认为，纤毛与鞭毛的周期性弯曲运动源于机械反馈：动力蛋白马达（dynein motors）产生滑动作用力使鞭毛弯曲，而弯曲会引发形变与应力，这些信号通过反馈调控动力蛋白马达。当前已提出三种备选反馈机制：基于滑动作用力的调控、基于鞭毛曲率的调控，以及基于使鞭毛横截面发生形变的法向力的调控。本研究结合理论与实验方法，证实曲率调控机制最契合衣藻（Chlamydomonas）鞭毛的弯曲波形特征。我们还得出一项意外的预测：动力蛋白马达响应的是曲率的时间导数，而非曲率本身，这暗示存在一种调控鞭毛摆动的适应机制。