title: Still and rotating myosin clusters determine cytokinetic ring constriction.
abstract: The cytokinetic ring is essential for separating daughter cells during division. It consists of actin filaments and myosin motors that are generally assumed to organize as sarcomeres similar to skeletal muscles. However, direct evidence is lacking. Here we show that the internal organization and dynamics of rings are different from sarcomeres and distinct in different cell types. Using micro-cavities to orient rings in single focal planes, we find in mammalian cells a transition from a homogeneous distribution to a periodic pattern of myosin clusters at the onset of constriction. In contrast, in fission yeast, myosin clusters rotate prior to and during constriction. Theoretical analysis indicates that both patterns result from acto-myosin self-organization and reveals differences in the respective stresses. These findings suggest distinct functional roles for rings: contraction in mammalian cells and transport in fission yeast. Thus self-organization under different conditions may be a generic feature for regulating morphogenesis in vivo.
authors.affiliation: Laboratory of Cell Physics ISIS/IGBMC, ISIS &icFRC, Université de Strasbourg &CNRS, 8 allée Gaspard Monge, Strasbourg 67000, France.|Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France.|Centre National de la Recherche Scientifique, UMR7104, Illkirch, France.|Institut National de la Santé et de la Recherche Médicale, U964, Illkirch, France.|Université de Strasbourg, Illkirch, France.|Theoretical Physics, Saarland University 66123, Saarbrücken, Germany.
authors.forename: Viktoria
authors.initials: V
authors.lastname: Wollrab
authors.affiliation: Laboratory of Cell Physics ISIS/IGBMC, ISIS &icFRC, Université de Strasbourg &CNRS, 8 allée Gaspard Monge, Strasbourg 67000, France.|Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France.|Centre National de la Recherche Scientifique, UMR7104, Illkirch, France.|Institut National de la Santé et de la Recherche Médicale, U964, Illkirch, France.|Université de Strasbourg, Illkirch, France.
authors.forename: Raghavan
authors.initials: R
authors.lastname: Thiagarajan
authors.affiliation: Theoretical Physics, Saarland University 66123, Saarbrücken, Germany.
authors.forename: Anne
authors.initials: A
authors.lastname: Wald
authors.affiliation: Theoretical Physics, Saarland University 66123, Saarbrücken, Germany.
authors.forename: Karsten
authors.initials: K
authors.lastname: Kruse
authors.affiliation: Laboratory of Cell Physics ISIS/IGBMC, ISIS &icFRC, Université de Strasbourg &CNRS, 8 allée Gaspard Monge, Strasbourg 67000, France.|Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France.|Centre National de la Recherche Scientifique, UMR7104, Illkirch, France.|Institut National de la Santé et de la Recherche Médicale, U964, Illkirch, France.|Université de Strasbourg, Illkirch, France.
authors.forename: Daniel
authors.initials: D
authors.lastname: Riveline
mesh_terms: D008841:Actin Cytoskeleton / Q000378:metabolism / Q000648:ultrastructure*; D002455:Cell Division / Q000502:physiology; D048749:Cytokinesis / Q000502:physiology*; D006367:HeLa Cells; D006801:Humans; D018613:Microscopy, Confocal; D009218:Myosins / Q000378:metabolism / Q000648:ultrastructure*; D012399:Rotation; D012518:Sarcomeres / Q000648:ultrastructure; D012568:Schizosaccharomyces; D029702:Schizosaccharomyces pombe Proteins / Q000378:metabolism / Q000648:ultrastructure*
chemical_list: D029702:Schizosaccharomyces pombe Proteins; D009218:Myosins