ESPCI web site
Cellular Morphodynamics : Shivering of Cellular Aggregates and Elasto-Capillary Instability of Mitochondria
In this talk I will present two problems in cell mechanics where insight is gained through physical modeling and analogies to inert systems. First I will discuss our work on cellular aggregates, a simple laboratory model of tissues and tumors. We have studied the behavior of cellular aggregates under stretching forces exerted by micropipette aspiration. In a certain range of aspiration pressures, the aggregate responds by pulsed contractions or “shivering”, which resembles a phenomenon observed in embryonic development. We explain the emergence of this shivering behavior by modeling the aggregate as an active viscoelastic material. The second part of the talk will focus on mitochondrial shape dynamics, a question of major biological importance, since disruption of mitochondrial morphology has been linked to neurodegenerative diseases. We experimentally observe that a mechanical perturbation induces a topological change in mitochondria, which fission from a tubular shape into a collection of spherical fragments. This shape change can be explained as an elasto-capillary instability, thus suggesting a role for mechanics in the regulation of mitochondrial morphology.