Regensburg 2013 – wissenschaftliches Programm
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BP: Fachverband Biologische Physik
BP 30: Tissue
BP 30.4: Vortrag
Donnerstag, 14. März 2013, 16:00–16:15, H43
Physarum polycephalum Percolation as a Paradigm for Topological Phase Transitions in Transportation Networks — •Adrian Fessel1,2, Christina Oettmeier1,2, Erik Bernitt1,2, Nils Gauthier2, and Hans-Günther Döbereiner1,2 — 1Institut für Biophysik, Universität Bremen — 2Mechanobiology Institute, National University of Singapore
As a foraging strategy, the slime mold Physarum polycephalum spans an extended vein network. If grown from disconnected pieces, evenly distributed in size, a giant component develops. Using tools from graph theory, this process can be understood as a percolation transition, driven by the distribution of node degrees (Fessel, PRL 109, 2012).
We present two analytical solutions for this topological transition, a two-dim. phase diagram representing the transition as a function of two node degree ratios and a one-dim. solution suitable for our system. Neither biological nor other constraints are taken into account, making the solutions universal for transportation networks, given local connectivity is low.
An experimental indication for universality can be found in vasculogenesis. Various malignant tissues mimic embryos which derive their blood vessels by fusing blood islands, i.e., aggregates of newly differentiated angioblast cells. This process can be studied in vitro by observing the behavior of plated endothelial cells. Reanalyzing such an experiment (Serini, EMBO 22, 2003) we find the same transition.
Due to the universal character of this process we conclude that percolation might serve as a gauge in anti-angiogenic theraphies.