title: Mechanochemical symmetry breaking in Hydra aggregates.
abstract: Tissue morphogenesis comprises the self-organized creation of various patterns and shapes. Although detailed underlying mechanisms are still elusive in many cases, an increasing amount of experimental data suggests that chemical morphogen and mechanical processes are strongly coupled. Here, we develop and test a minimal model of the axis-defining step (i.e., symmetry breaking) in aggregates of the Hydra polyp. Based on previous findings, we combine osmotically driven shape oscillations with tissue mechanics and morphogen dynamics. We show that the model incorporating a simple feedback loop between morphogen patterning and tissue stretch reproduces a wide range of experimental data. Finally, we compare different hypothetical morphogen patterning mechanisms (Turing, tissue-curvature, and self-organized criticality). Our results suggest the experimental investigation of bigger (i.e., multiple head) aggregates as a key step for a deeper understanding of mechanochemical symmetry breaking in Hydra.
authors.affiliation: Institute of Applied Mathematics, University of Heidelberg, Heidelberg, Germany; BioQuant, University of Heidelberg, Heidelberg, Germany; Interdisciplinary Center for Scientific Computing (IWR), University of Heidelberg, Heidelberg, Germany. Electronic address: mmercker_bioscience@gmx.de.
authors.forename: Moritz
authors.initials: M
authors.lastname: Mercker
authors.affiliation: Institute of Applied Mathematics, University of Heidelberg, Heidelberg, Germany.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Köthe
authors.affiliation: Institute of Applied Mathematics, University of Heidelberg, Heidelberg, Germany; BioQuant, University of Heidelberg, Heidelberg, Germany; Interdisciplinary Center for Scientific Computing (IWR), University of Heidelberg, Heidelberg, Germany.
authors.forename: Anna
authors.initials: A
authors.lastname: Marciniak-Czochra
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D006829:Hydra / Q000254:growth & development*; D008954:Models, Biological; D009024:Morphogenesis; D009994:Osmolar Concentration