Gene

Cell biology

Motility

Cilium

Biology

Dynein

Microtubule

Genetics

Flagellum

Biophysics

Science

Switching how to make flagella beat Motile cilia and flagella are hairlike cellular appendages that power the movement of individual cells or liquid across tissues, as exemplified by the cilia found in airways. The question of how they move in rhythmic oscillations has puzzled scientists for centuries. Lin and Nicastro used cryo–electron tomography (cryo-ET) to visualize the activity states of individual dynein motors with respect to their locations within beating flagella. They observed an asymmetric distribution of dynein activity and the switching of conformations of dyneins and their regulators between opposite sides of active flagella. The results confirm the switching aspect of the prevailing “switch-point” hypothesis but change the view with respect to how dynein activities are coordinated to drive flagellar motility. Science , this issue p. eaar1968

Asymmetric distribution and spatial switching of dynein activity generates ciliary motility