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BP: Fachverband Biologische Physik
BP 2: Physics of Cells I
BP 2.11: Talk
Monday, March 26, 2012, 12:30–12:45, H 1028
Quantitative Investigations of Circular Dorsal Ruffling Dynamics — •Erik Bernitt1,3, Malte Ohmstede1, Pritpal Singh2, Cheng-Gee Koh2, and Hans-Günther Döbereiner1,3 — 1Institut für Biophysik, Universität Bremen, 28334 Bremen — 2School of Biological Sciences, Nanyang Technological University, 639798 Singapore — 3Mechanobiology Institute Singapore, National University of Singapore, 117411 Singapore
Circular dorsal ruffles (CDRs) are actin-based structures that, unlike peripheral ruffles, form on the dorsal side of cells. Upon initialization, a membrane sheet of vertical extension forms that propagates in a ring-like fashion over the cell. After formation CDRs enlarge, sometimes covering the complete dorsal side of the cell, propagate and collapse to one point. CDRs are known to occur, e.g., on fibroblast cells upon growth factor stimulation. Even though this has been known for decades, the underlying mechanisms leading to formation and propagation of these coherent solitary waves are not understood. Only recently models have been published that describe CDRs based on diffusion reaction processes in the cytosol and on the membrane.
We use DIC-based optical sectioning in conjunction with image processing for localisation and the three-dimensional reconstruction of CDR morphology. We are the first to describe the CDR dynamics in terms of morphology and propagation velocities in great detail. We correlate these data with fluorenscence data of the actin cytoskeleton, providing the first dynamic data on the onset of the migratory state, one hypothesized biological function of CDRs.