title: Insights into the micromechanical properties of the metaphase spindle.
abstract: The microtubule-based metaphase spindle is subjected to forces that act in diverse orientations and over a wide range of timescales. Currently, we cannot explain how this dynamic structure generates and responds to forces while maintaining overall stability, as we have a poor understanding of its micromechanical properties. Here, we combine the use of force-calibrated needles, high-resolution microscopy, and biochemical perturbations to analyze the vertebrate metaphase spindle's timescale- and orientation-dependent viscoelastic properties. We find that spindle viscosity depends on microtubule crosslinking and density. Spindle elasticity can be linked to kinetochore and nonkinetochore microtubule rigidity, and also to spindle pole organization by kinesin-5 and dynein. These data suggest a quantitative model for the micromechanics of this cytoskeletal architecture and provide insight into how structural and functional stability is maintained in the face of forces, such as those that control spindle size and position, and can result from deformations associated with chromosome movement.
authors.affiliation: Laboratory of Chemistry and Cell Biology, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA.
authors.forename: Yuta
authors.initials: Y
authors.lastname: Shimamoto
authors.forename: Yusuke T
authors.initials: YT
authors.lastname: Maeda
authors.forename: Shin'ichi
authors.initials: S
authors.lastname: Ishiwata
authors.forename: Albert J
authors.initials: AJ
authors.lastname: Libchaber
authors.forename: Tarun M
authors.initials: TM
authors.lastname: Kapoor
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D002457:Cell Extracts / Q000737:chemistry; D004398:Dyneins / Q000502:physiology; D004548:Elasticity; D016547:Kinesins / Q000502:physiology; D008677:Metaphase; D008870:Microtubules / Q000502:physiology; D010063:Ovum / Q000737:chemistry; D008941:Spindle Apparatus / Q000737:chemistry* / Q000502:physiology*; D029867:Xenopus Proteins / Q000502:physiology; D014982:Xenopus laevis / Q000502:physiology*
chemical_list: D002457:Cell Extracts; C088335:KIF11 protein, Xenopus; D029867:Xenopus Proteins; D004398:Dyneins; D016547:Kinesins