Dresden 2011 – wissenschaftliches Programm
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BP: Fachverband Biologische Physik
BP 13: Posters: Biological Membranes
BP 13.6: Poster
Montag, 14. März 2011, 17:15–20:00, P3
The process of symmetry break on two-dimensional, biofunctionalized surfaces — •Alexander Körner1, Fernanda Rossetti1, Christina Deichmann2, Almut Köhler2, Doris Wedlich2, and Motomu Tanaka1 — 1Institut of Physical Chemistry, University of Heidelberg, Germany — 2Institut of Zoology 2, Institut of Technology Karlsruhe, Germany
A challenge in developmental biology is to understand how tissue structures evolve from uniform cell ensembles. The initial step can be generalized as the break of symmetry, which can be characterized by changes in cell polarity. In-vivo studies suggested that a change in cell polarity is induced by the gradient of morphogens (e.g. Wnt), little is known about the quantitative mechanisms. The main focus of this study is to design a model system for the formation of central nerval systems in Xenopus. Our strategy is to use two-dimensional, model membranes functionalized with cell adhesion molecules (Xcadherin 11) to give a cue that guides the symmetry break in tissue explants (animal caps) in a quantitative manner. The precise control of the lateral density of cadherin on the membrane surface was confirmed from changes in the mass density detected by a Quartz Crystal Microbalance. The thickness, roughness, and electron density of supported membranes in the presence and absence of cadherin molecules were determined by high energy X-ray reflectivity measurements. After confirming the quantitative functionalization, we placed Xenopus animal cap onto supported membranes exposing Xcadherin 11, and found that cells injected with a promoter gene showed a sign of the change in their polarity.