INPHYNI seminar: Marco Polin

Cilia and flagella are active slender filaments whose beating is generated by internally driven molecular motors. From a physical perspective, each flagellum can be regarded as a self-sustained oscillator operating in the low–Reynolds-number regime. When multiple flagella are in close proximity, their oscillatory dynamics often become strongly coordinated, leading to robust phase locking. The central physical question is therefore: what interactions generate the effective coupling between these active oscillators?

Taking ciliated green algae as a paradigmatic example, here I will discuss our current understanding of the importance of both hydrodynamics and direct mechanical coupling in flagellar synchronisation. I will then present the results of new experiments which allow us to selectively block hydrodynamic coupling between the flagella of a single cell and therefore probe directly the role of hydrodynamics in their synchronisation. These results reveal a link between the type of coupling and the resulting synchronisation state, and suggest a previously unrecognised mechanism by which flagella can sense mechanical stimuli