Dresden 2020 – wissenschaftliches Programm
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BP 10.8: Poster
Montag, 16. März 2020, 17:30–19:30, P2/3OG
Calcium as a key regulator in Physarum polycephalum — •Björn Kscheschinski1, Mirna Kramar1, and Karen Alim1,2 — 1Max Planck Institute for Dynamics and Self-Organization, Göttingen — 2Technical University of Munich
The tubular network-forming slime mold Physarum polycephalum is able to maintain long-scale contraction patterns driven by an acto-myosin cortex forming the tube walls. The resulting flow transports mass effectively in the organism. Recent models suggest feedback mechanisms for self-oragnized contractions by coupling the acto-myosin activity to a regulating chemical, which is in turn advected by the flow. These models predict system sized contraction patterns. However, the exact effect of the regulating chemical is not yet fully understood. Here, we present ratiometric measurements of free intracellular calcium in single Physarum tubes suggesting an inhibitory effect of calcium on the acto-myosin activity. The spatio-temporal patterns of the free calcium concentration reveal an anti-correlated relation to the tube diameter, while the main patterns of the contractions are preserved. By controlling the morphology of Physarum we can relate our experimental data directly to numerical simulations with simple geometries. Our results suggest that calcium is a key regulator of the acto-myosin activity enabling the organized flow patterns emerging in Physarum networks. Thus, our findings might allow further insights into processes in Physarum related to the flows.