Section: New Results

Analysis of spatio-temporal dynamics of cytoplasmic actin under geometrical confinement

Participant : Charles Kervrann.

The generation, cell-cycle regulation and maintenance of such cellular functions are often correlated with symmetry breaking and spatiotemporal reorganization of F-actin assembly. In this study, we analyzed the spatiotemporal evolution of actin filaments using Xenopus meiotic extracts artificially confined within a geometry mimicking the cell boundary. It turns out the confinement of the cytoplasm generates symmetry breaking in the spatial organization of actin filaments. Combination of quantitative image analysis and biochemical perturbations show that both spatial localization of F-actin nucleators and actin turnover play a decisive role in generating symmetry breaking. In this project, we proposed to combine an optical flow-based tracker (Kanade-Lucas-Tomasi tracker [40] , [36] ) to a photobleaching correction method in order to extract quantitative spatiotemporal characteristics of the actin dynamics.

Partners: Z. Gueroui (BioPhysics team, UMR 8640 Ecole Normale Superieure, Paris) and M. Pinot (UMR 144 CNRS Institut Curie, Paris)