Regensburg 2016 – scientific programme
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SOE: Fachverband Physik sozio-ökonomischer Systeme
SOE 25: Networks: From Topology to Dynamics (joint session BP / SOE / DY)
SOE 25.1: Talk
Thursday, March 10, 2016, 16:45–17:00, H43
Fluctuations and transients in the actin cytoskeleton of chemotactic amoeba — •Jose Negrete JR1,2, Alain Pumir3, Hsing-Fang Hsu2, Christian Westendorf4, Marco Tarantola2, Carsten Beta2,5, and Eberhard Bodenschatz2,6,7 — 1Max Planck Institute for the Physics of Complex Systems, Dresden, Germany — 2Max Planck Institute for Dynamics and Selforganization, Göttingen, Germany — 3Ecole Normale Supérieure de Lyon, France — 4University of Graz, Austria — 5University of Potsdam, Germany — 6University of Göttingen, Germany — 7Cornell University, Ithaca, USA
Biological systems with their complex biochemical networks are known to be intrinsically noisy. Here we investigate the oscillatory dynamics in the actin cytoskeleton of chemotactic amoeboid cells. We show that the large phenotypic variability in the polymerization dynamics can be accurately captured by a generic nonlinear oscillator model in the presence of noise. The relative role of the noise is fully determined by a single dimensionless parameter, experimentally measurable, and whose distribution completely characterizes the possible cellular behavior. Also, we perturbed experimentally the oscillatory cytoskeletal dynamics by a short chemoattractant pulse and measured the spatio-temporal response of filamentous actin reporter, LimE, and depolymerization regulators Coronin1 and Aip1. After pulsing, we observed self oscillating cells to relax back to their oscillatory state after a noisy transient. Particularly long transients were observed for cells initially displaying highly correlated oscillations.