Berlin 2015 – wissenschaftliches Programm
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BP: Fachverband Biologische Physik
BP 19: Multi-cellular systems
BP 19.6: Vortrag
Dienstag, 17. März 2015, 11:15–11:30, H 1058
Epithelial tissue growth and organization: mystery or physics? — •Sara Kaliman1, Carina Wollnik2, Damir Vurnek1, Florian Rehfeldt2, and Ana-Sunčana Smith1 — 1Institut fur Theoretische Physik, FAU, Erlangen — 23rd Institute of Physics-Biophysics, Uni Gottingen
Tissue growth is a complex and indisputably important process but despite all the effort in past decades mechanism remains unclear. As model system for such study we have chosen MDCK II cell line seeded on polyacrylamide gels or glass substrates. In most common scenario cluster of cells forms radial monolayers with very dense bulk surrounded by a low density ring of a moving and proliferating edge. To elucidate the mechanism behind compartmentalization to bulk and edge we have simulated cluster growth with Voronoi tessellation model. In the simulation we use measured area growth of the cluster, proliferation rates and speed distribution inside the cluster. Our aim is to distinguish passive from active mechanism during epithelial tissue development. Furthermore, we answer is organization of cells in the tissue random. To do so we compare various morphological parameters of real tissue with randomly distributed mono-disperse and poly-disperse circles and ellipses. We find that elongation and size distribution of nuclei predetermines cell shapes and correlations in the tissue. Lastly, we write free energy functional as a sum of morphological and elastic term and prove that tissue minimizes energy as it approaches steady state density and undergoes phase transition at intermediate densities when surface tension of cell membrane starts to play a role.