Visualization of dynein-dependent microtubule gliding at the cell cortex: implications for spindle positioning

• Author(s) / Creator(s)

  • Srayko, M.
  • Gusnowski, E.M.

• Dynein motors move along the microtubule (MT) lattice in a processive “walking” manner. In the one-cell Caenorhabditis elegans embryo, dynein is required for spindle-pulling forces during mitosis. Posteriorly directed spindle-pulling forces are higher than anteriorly directed forces, and this imbalance results in posterior spindle displacement during anaphase and an asymmetric division. To address how dynein could be asymmetrically activated to achieve posterior spindle displacement, we developed an assay to measure dynein’s activity on individual MTs at the embryo cortex. Our study reveals that cortical dynein motors maintain a basal level of activity that propels MTs along the cortex, even under experimental conditions that drastically reduce anaphase spindle forces. This suggests that dynein-based MT gliding is not sufficient for anaphase spindle-pulling force. Instead, we find that this form of dynein activity is most prominent during spindle centering in early prophase. We propose a model whereby different dynein–MT interactions are used for specific spindle-positioning tasks in the one-cell embryo.

• Date created

  2011

• Subjects / Keywords

  • Caenorhabditis-elegans embryos
  • Polarity
  • Mitotic spindle
  • Localization
  • Proteins
  • Division
  • G-alpha
  • Force
  • Cytoplasmic dynein
  • C-elegans

• Type of Item

  Article (Published)

• DOI

  https://doi.org/10.7939/R3F47GX0T

• License

  © 2011 Gusnowski and Srayko This article is distributed under the terms of a Creative Commons License (Attribution–Noncommercial–Share Alike 3.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/3.0/).