BEGIN:VCALENDAR VERSION:2.0 PRODID:-//Talks.cam//talks.cam.ac.uk// X-WR-CALNAME:Talks.cam BEGIN:VEVENT SUMMARY:Modeling of Cell Movement on Adhesive Substrates - Aronson\, I (Ar gonne National Laboratory) DTSTART:20130628T100000Z DTEND:20130628T104500Z UID:TALK45985@talks.cam.ac.uk CONTACT:Almarie Williams DESCRIPTION:Modeling the movement of living motile cells on substrates is a formidable challenge\; regulatory pathways are intertwined and forces th at influence cell motion on adhesive substrates are not fully quantified. Here\, we present a mathematical model coupling cell shape dynamics\, trea ted in the framework of the Ginzburg-Landau-type equation for auxiliary ma ss density (phase field)\, to a partial differential equation describing t he mean orientation (polarization of actin filaments) of the cell's cytosk eletal network. In order to maintain the total area of the cell\, the phas e field equation is subject to a global conservation constraint. Correspon dingly\, the equation for mean polarization incorporates key elements of c ell mechanics: directed polymerization of actin network at the cell membra ne\, decay of polarization in the bulk of the cell\, and formation of acti n bundles (stress fibers) in the rear. The model successfully reproduces t he primary phenomenology of cell motil ity: discontinuous onset of motion\ , diversity of cell shapes and shape oscillations\, as well as distributio n of traction on the surface. The results are in qualitative agreement wit h recent experiments on the motility of keratocyte cells and cell fragment s. The asymmetry of the shapes is captured to a large extent in this simpl e model\, which may prove useful for the interpretation of recent experime nts and predictions of cell dynamics under various conditions. We also inv estigate effects of adhesion and substrate elasticity on the shape and dyn amics of moving cells. We demonstrate that on hard adhesive substrates the cells exhibit steady-state motion. A transition to stick-slip motion is o bserved on soft and weakly adhesive surfaces. \n