Regensburg 2019 – wissenschaftliches Programm

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DY: Fachverband Dynamik und Statistische Physik

DY 15: Pattern Formation

DY 15.12: Vortrag

Dienstag, 2. April 2019, 13:00–13:15, H3

Boundary driven oscillations in Dictyostelium discoideum — •Torsten Eckstein, Estefania Vidal-Henriquez, and Azam Gholami — Max Planck Institute for Dynamics and Self-Organization, Goettingen, Germany

Dictyostelium discoideum amoeba aggregate if deprived of nutrients, producing wave patterns of a chemo attractant called cyclic adenosine monophosphate (cAMP). To successfully produce waves, the role of degradation of cAMP by phosphodiesterase is fundamental, preventing the accumulation of cAMP and producing the gradients necessary for cell detection. The knockout mutant pdsA⁻ can not produce the most active type of phosphodiesterase and therefore does not show pattern formation under normal circumstances. Using a microfliuidic channel, we show how an advective flow can partially recover signaling in this system. Above a minimum flow velocity decaying waves are induced, with a decay length that scales with the applied flow speed. After stopping the advecting flow, the cells continue to signal, showing normal structures and aggregation, although with a wave period much higher than in wild type cells. Extensive numerical simulations showed that these waves have a boundary driven origin, where the lack of cAMP in the upstream flow destabilizes the system. We explored the parameter region where these waves exist and their properties, with good agreement with our experimental observations. The results here presented provide experimental confirmation of the destabilizing effect of the upstream boundary in an otherwise stable reaction-diffusion system.