title: Rheology of the Active Cell Cortex in Mitosis.
abstract: The cell cortex is a key structure for the regulation of cell shape and tissue organization. To reach a better understanding of the mechanics and dynamics of the cortex, we study here HeLa cells in mitosis as a simple model system. In our assay, single rounded cells are dynamically compressed between two parallel plates. Our measurements indicate that the cortical layer is the dominant mechanical element in mitosis as opposed to the cytoplasmic interior. To characterize the time-dependent rheological response, we extract a complex elastic modulus that characterizes the resistance of the cortex against area dilation. In this way, we present a rheological characterization of the cortical actomyosin network in the linear regime. Furthermore, we investigate the influence of actin cross linkers and the impact of active prestress on rheological behavior. Notably, we find that cell mechanics values in mitosis are captured by a simple rheological model characterized by a single timescale on the order of 10 s, which marks the onset of fluidity in the system.
authors: Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany; Max Planck Institute for the Physics of Complex Systems, Dresden, Germany.
authors: Elisabeth
authors: E
authors: Fischer-Friedrich
authors: Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany; Institute of Life Science, Kurume University, Kurume, Japan.
authors: Yusuke
authors: Y
authors: Toyoda
authors: Department of Biosystems Science and Engineering, Eidgenössische Technische Hochschule Zürich, Basel, Switzerland.
authors: Cedric J
authors: CJ
authors: Cattin
authors: Department of Biosystems Science and Engineering, Eidgenössische Technische Hochschule Zürich, Basel, Switzerland.
authors: Daniel J
authors: DJ
authors: Müller
authors: Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany. Electronic address: hyman@mpi-cbg.de.
authors: Anthony A
authors: AA
authors: Hyman
authors: Max Planck Institute for the Physics of Complex Systems, Dresden, Germany. Electronic address: julicher@pks.mpg.de.
authors: Frank
authors: F
authors: Jülicher
mesh_terms: D001696:Biomechanical Phenomena; D002462:Cell Membrane / Q000378:metabolism*; D004548:Elasticity; D006367:HeLa Cells; D006801:Humans; D008938:Mitosis; D012212:Rheology; D014783:Viscosity