Berlin 2018 – wissenschaftliches Programm
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DY: Fachverband Dynamik und Statistische Physik
DY 44: Pattern Formation I
DY 44.7: Vortrag
Mittwoch, 14. März 2018, 12:15–12:30, BH-N 334
Spontaneous formation of target centers in D.discoideum — •Estefania Vidal-Henriquez1, Vladimir Zykov1, Bodenschatz Eberhard1,2,3, and Gholami Azam1 — 1Max Planck Institute for Dynamics and Self-Organization, Am Fassberg 17, D-37077 Goettingen, Germany — 2Institute for Nonlinear Dynamics, University of Goettingen, D-37073 Goettingen, Germany — 3Laboratory of Atomic and Solid-State Physics and Sibley School of Mechanical and Aerospace Engineering, Cornell University, Ithaca, New York 14853, USA
Dyctiostelium discoideum is a social amoeba that produces target patterns and spiral waves of cyclic AMP as a way to form multicellular aggregates when subjected to adverse environmental conditions. The stability of pacemakers at the interior of a target wave presents a modeling challenge in such organism, since in its classical description the limit cycle produces bulk (whole system) oscillations. We present a novel and robust way of producing target waves based on non-artificial conditions. Using the cell density in a discrete way, the bigger cell clusters become centers, as observed in experiments. We characterize the emission frequency of the centers and the capability of the rest of the system to react to them, depending on the cell coverage. The wave velocity is density dependent, thus producing aggregation streams. This model emphasizes the importance of external unbounded phosphodiesterase, upon which the system can change between oscillatory and excitable regimes allowing to reproduce many of the experimentally observed properties. Finally we discuss boundary conditions and the density differences necessary to artificially induce target centers.