The ability to move certainly is one of the most striking features of living matter. This ability has been declined during the evolution in different forms depending on the size and the shape of the individuals and on the habitat and environment ;  it  implies that some choices have to be made (direction, velocity) and some animals have even acquired the capacity to develop different gaits. I present in this talk experiments performed with two model micro-organisms, Caenorhabditis elegans (a nematode worm) and Dictyostelium discoideum (an amoeba) where we study the selection of gait as a function of the environment (C. elegans) or the collective migration and differentiation in microfluidic channels (D. discoideum).

Jean-Marc has PhD in physics and engineering from the École Supérieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI-Paris Tech) in 1984. After a post-doc at the U. Pennsylvania and time in the Exxon Research Center in New Jersey, he joined the Condensed Matter Physics laboratory of the Collège de France in Paris as a CNRS Fellow where he worked with 1991 Nobel Laurette Pierre-Giles de Gennes. He moved to the University of Strasbourg in 1994.  He spent a year Department of Applied Mathematics with Tim Senden, before taking his present position in 2002 at the University Paris Diderot as founding director of the Matière et Systèmes Complexes laboratory, one of the largest laboratories in France dedicated to soft matter and biological physics. His scientific contributions concern soft-matter physics: polymers, liquid crystals. vesicles. capillarity, wetting, foams and now focussed mostly on biophysics. Using the nematode worm C. elegans, he is interested in the relationship between perception and mechanics in locomotion. He also started a research program on the collective motion of the social amoeba Dictyostelium discoideum in collaboration with Dr. Alexandre Kabla (University of Cambridge, formally Department of Applied Mathematics) as a Fellow of Churchill College in 2011-2012. He is editor-in-chief of the European Physical Journal E – Soft matter and biological physics.