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SYNF: Symposium Nonlinear and Fractional Transport in Complex Systems

SYNF 1: Nonlinear and Anomalous Transport in Complex Systems

SYNF 1.2: Invited Talk

Wednesday, March 28, 2007, 15:15–15:45, H1

Hydra Molecular Network Reaches Criticality at the Symmetry-Breaking Axis-Defining Moment — Jordi Soriano¹, Cyril Colombo², and •Albrecht Ott¹ — ¹Lehrstuhl Experimentalphysik 1, Universität Bayreuth, Bayeuth, Germany — ²EADS Space Transportation, Les Muraux, France

We study biological, multicellular symmetry breaking on a hollow cell sphere as it occurs during hydra regeneration from a random cell aggregate. We show that even a weak temperature gradient directs the axis of the regenerating animal - but only if it is applied during the symmetry-breaking moment. We observe that the spatial distribution of the early expressed, head-specific gene ks1 has become scale-free and fractal at that point. We suggest the self-organized critical state to reflect long range signaling, which is required for axis definition and arises from cell next-neighbor communication.