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BP: Fachverband Biologische Physik

BP 17: Microswimmers (joint DY/BP)

BP 17.9: Talk

Tuesday, April 1, 2014, 11:45–12:00, ZEU 146

Direct Measurements of Active Flagellar Fluctuations — •Benjamin Friedrich¹, Rui Ma², Gary Klindt¹, Frank Julicher¹, and Ingmar Riedel³ — ¹Max Planck Institute for the Physics of Complex Systems — ²Institute for Advanced Study, Tsinghua University, Beijing, China — ³Department of Bioengineering, Stanford University, Stanford, CA, USA

The eukaryotic flagellum beats regularly, driven by the oscillatory dynamics of molecular motors, to propel cells and pump fluids. Small, but perceivable fluctuations in the beat of individual flagella have physiological implications for synchronization in collections of flagella as well as for hydrodynamic interactions between flagellated swimmers. Here, we characterize phase diffusion and amplitude fluctuations of sperm flagellar beat patterns. We employ shape mode analysis and limit cycle reconstruction for a low-dimensional representation of flagellar bending waves. We find that flagellar fluctuations are dominantly of active origin. Using a minimal model of collective motor oscillations, we demonstrate how active fluctuations can naturally arise from the stochastic dynamics of individual motors.