title: Shell tension forces propel Dictyostelium slugs forward.
abstract: The Dictyostelium slug is an excellent model system for studying collective movements, as it is comprised of about 10(5) cells all moving together in the same direction. It still remains unclear how this movement occurs and what the physical mechanisms behind it are. By applying our recently developed 3D traction force microscopy, we propose a simple explanation for slug propulsion. Most of the forces are exerted by the sheath surrounding the slug. This secreted shell is under a rather uniform tension (around 50 mN m(-1)) and will give rise to a tissue under pressure. Finally, we propose that this pressure will naturally push the slug tip forwards if a gradient of shell mechanical properties takes place in the very anterior part of the raised tip.
authors.affiliation: Laboratoire de Physique de la Matière Condensée et Nanostructures, CNRS, Université de Lyon, Université Claude Bernard Lyon I, UMR 5586, 43 Boulevard du 11 Novembre 1918, F-69622 Villeurbanne Cedex, France. jean-paul.rieu@univ-lyon1.fr
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Rieu
authors.forename: Hélène
authors.initials: H
authors.lastname: Delanoë-Ayari
mesh_terms: D001696:Biomechanical Phenomena; D002465:Cell Movement; D002478:Cells, Cultured; D004023:Dictyostelium / Q000737:chemistry / Q000166:cytology* / Q000502:physiology*; D009068:Movement