8th Liquid Matter Conference September 6-10, 2011 Wien, Austria ...

Tue 611:23-14:00P10.21Cell motility: a viscous fingering analysis of active gelsOksana Manyuhina, 1 Martine Ben Amar, 1 and Gaetano Napoli 21 Ecole Normale Superieure, 24 rue Lhomond, 75005, Paris, France2 Dipartimento di Ingegneria dell’Innovazione Universita del Salento, Lecce, ItalyThe symmetry breaking of the actin network from radial to longitudinal symmetry has been identifiedas the major mechanism for keratocytes (fish cells) motility on solid substrate. For strongfriction coefficient, the two dimensional actin flow which includes the polymerisation at the edgeand depolymerisation in the bulk can be modelled as a Darcy flow, the cell shape and dynamicsbeing then modelled by standard complex analysis methods. We use the theory of active gels todescribe the orientational order of the filaments which varies from the border to the bulk. We showanalytically that the reorganisation of the cortex is enough to explain the motility of the cell andfind the velocity as a function of the tensorial order parameter in the bulk.21