Beating of eukaryotic flagella via Hopf bifurcation of a system of stalled molecular motors

TL;DR

This paper presents a nonlinear multiscale model of eukaryotic flagella beating, demonstrating how molecular motor dynamics lead to oscillatory motion via a Hopf bifurcation, validated through stability analysis and simulations.

Contribution

It introduces a new nonlinear model based on sliding feedback that links microscopic motor activity to macroscopic flagellar oscillations, advancing understanding of flagella dynamics.

Findings

Oscillations emerge through a Hopf bifurcation.

Model aligns with experimental observations of flagellar beating.

Comparison with existing models highlights unique features of the proposed approach.

Abstract

The modeling of the beating of cilia and flagella in fluids is a particularly active field of study, given the biological relevance of these organelles. Various mathematical models have been proposed to represent the nonlinear dynamics of flagella, whose motion is powered by the work of molecular motors attached to filaments composing the axoneme. Here, we formulate and solve a nonlinear model of activation based on the sliding feedback mechanism, capturing the chemical and configurational changes of molecular motors driving axonemal motion. This multiscale model bridges microscopic motor dynamics with macroscopic flagellar motion, providing insight into the emergence of oscillatory beating. We validate the framework through linear stability analysis and fully nonlinear numerical simulations, showing the onset of spontaneous oscillations. To make the analysis more comprehensive, we compare our approach with two established sliding feedback models.