Physics Colloquium - Thursday, January 21st, 2010, 3:00 P.M.

Leonard Sander
Physics Department
University of Michigan

The mechanics of cell motility has a number of surprising features that need to be included in biophysical models of the process. Recent experiments on the motion of the ameba Dictyostelium discoideum in chemotaxis show that contractile forces on the substrate are two orders of magnitude larger than the force necessary to propel the cell forward against fluid friction. Most of the work done by the cell goes towards peeling it from the substrate (breaking the adhesive bonds); viscoelastic effects and friction are completely negligible. We give a new mechanical model based on this idea, and show how it agrees with experimental results on the cell speed of wild-type and mutated dicty.