Dresden 2014 – wissenschaftliches Programm
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BP: Fachverband Biologische Physik
BP 38: Active cell and tissue mechanics (focus session) II
BP 38.4: Vortrag
Donnerstag, 3. April 2014, 16:00–16:15, HÜL 386
Active mechanics and dynamics of epithelia during morphogenesis — •Amitabha Nandi1, Marko Popovic1, Matthias Merkel1, Raphaël Etournay2, Suzanne Eaton2, Guillaume Salbreux1, and Frank Jülicher1 — 1Max-Planck Institute for the Physics of Complex Systems, Nöthnitzer Str. 38, 01187 Dresden, Germany — 2Max-Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany
During development of an organism, epithelial tissues are dynamically remodeled due to forces generated in the cells, cellular rearrangements, and cell division and apoptosis. Such remodeling occurring over long time-scales leads to reorganization of the tissue allowing to establish the shape of the organism. In this work, we introduce a physical description of the slow timescale behavior of an epithelium. We obtain the hydrodynamic constitutive equations describing the continuum mechanics of an epithelium in two dimensions on spatial scales larger than a cell. Within this framework, topological rearrangements relax elastic stresses in the tissue and can be actively triggered by internal cell processes. We study simple limit cases of the flows and deformation predicted by the continuum theory. Using segmentation of the wing disc cell packing at pupal stage of the fly, we analyze experimental coarse-grained patterns of flow field and tissue shear. We show that our continuum theory can account for the key features of the cell flow and deformation fields. We find that a gradient of active contractile stress acting together with active cell rearrangement that are polarized in the tissue plane can explain the flow patterns observed in experiments.