Viscoelastic dynamics of the cell cortex

The actin cortex in conjunction with the cell membrane is a thin film that encloses the viscous interior of most animal cells. The actin cortex is a complex viscoelastic material which exhibits active prestress due to inherent microscopic force-dipoles constituted by molecular myosin motor proteins. Observations of cells show that the actin cortex film can form self-organized patterns and actively deform itself. The cortex is thus a key regulator for the emergence of cell shape and vital for cell function for instance during cell division. The biological importance of the cortex is illustrated in the large number of biological publications on the biochemistry and the mechanics of the cortex in the last decade.However, to date, the increasing experimental attention to viscoelastic cortex dynamics is not yet reflected in the e˙orts in mathematical modelling. In particular no numerical method is available to simulate viscoelastic surfaces enveloping a viscous interior fluid. The goal of the proposed project is to quantify the mechanical properties of the cell cortex in a close collaboration of numerical simulations and experimental measurements. In a first part, we will develop and analyze a mathematical model of an active viscoelastic surface immersed in viscous fluids. The model will

FIS:VIVO