BEGIN:VCALENDAR VERSION:2.0 PRODID:-//Talks.cam//talks.cam.ac.uk// X-WR-CALNAME:Talks.cam BEGIN:VEVENT SUMMARY:Mechanics and polarity in cell motility - Davide Ambrosi (Politecn ico di Milano) DTSTART:20170921T111000Z DTEND:20170921T113000Z UID:TALK80441@talks.cam.ac.uk CONTACT:INI IT DESCRIPTION: The motility of a fish keratocyte on a flat s ubstrate exhibits two distinct regimes: the non-migrating and the migrat ing one. In both configurations the shape is fixed in time and\, when th e cell is moving\, the velocity is constant in magnitude and direction. Transition from a stable configuration to the other one can be produced by a mechanical or chemotactic perturbation.
In order to point out the mechanical nature of such a bistable behaviour\, I will focus on th e actin dynamics inside the cell using a minimal mathematical model. Whi le the protein diffusion\, recruitment and segregation govern the polari zation process\, I will show that the free actin mass balance\, driven by diffusion\, and the polymerized actin
retrograde flow\, regulate d by the active stress\, are sufficient ingredients to account for the m otile bistability.
The length and velocity of the cell are predict ed on the basis of the parameters of the substrate and of the cell itsel f. The key physical ingredient of the theory is the exchange among actin phases at the edges of the cell\, that plays a central role both in kin ematics and in dynamics. LOCATION:Seminar Room 1\, Newton Institute END:VEVENT END:VCALENDAR