Skip to main content
bioRxiv
  • Home
  • About
  • Submit
  • ALERTS / RSS
Advanced Search
New Results

Mapping load-bearing in the mammalian spindle reveals local kinetochore-fiber anchorage that provides mechanical isolation and redundancy

View ORCID ProfileMary Williard Elting, Manu Prakash, Dylan B. Udy, Sophie Dumont
doi: https://doi.org/10.1101/103572
Mary Williard Elting
Department of Cell and Tissue Biology, UCSF, San Francisco, CA 94143 USA
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
  • ORCID record for Mary Williard Elting
Manu Prakash
Department of Bioengineering, Stanford University, Stanford, CA 94305 USA
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Dylan B. Udy
Department of Cell and Tissue Biology, UCSF, San Francisco, CA 94143 USA
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
Sophie Dumont
Department of Cell and Tissue Biology, UCSF, San Francisco, CA 94143 USA Department of Cellular and Molecular Pharmacology, UCSF, San Francisco, CA 94143 USA
  • Find this author on Google Scholar
  • Find this author on PubMed
  • Search for this author on this site
  • For correspondence: sophie.dumont@ucsf.edu
  • Abstract
  • Full Text
  • Info/History
  • Metrics
  • Supplementary material
  • Preview PDF
Loading

Summary

Active forces generated at kinetochores move chromosomes, and the dynamic spindle must robustly anchor kinetochore-fibers (k-fibers) to bear this load. We know that the mammalian spindle body can bear the load of chromosome movement far from poles, but do not know where and how – physically and molecularly – this load is distributed across the spindle. In part, this is because perturbing and reading out spindle mechanics in live cells is difficult. Yet, answering this question is key to understanding how the spindle generates and responds to force, and performs its diverse mechanical functions. Here, we map load-bearing across the mammalian spindle in space-time, and dissect local anchorage mechanics and mechanism. To do so, we laser ablate single k-fibers at different spindle locations, and in different molecular backgrounds, and quantify at high time resolution the immediate relaxation of chromosomes, k-fibers, and microtubule speckles. We find that load redistribution is locally confined in all directions: along the first 3-4 μm from kinetochores, scaling with k-fiber length, and laterally within ~2 μm of k-fiber sides, without neighboring k-fibers sharing load. A phenomenological model constrains the mechanistic underpinnings of these data: it suggests that dense, transient crosslinks to the spindle along k-fibers bear the load of chromosome movement, but that these connections do not limit the timescale of spindle reorganization. The microtubule crosslinker NuMA is needed for the local load-bearing observed, while Eg5 and PRC1 are not, suggesting specialization in mechanical function and a novel function for NuMA throughout the spindle body. Together, the data and model suggest that widespread NuMA-mediated crosslinks locally bear load, providing mechanical isolation and redundancy while allowing spindle fluidity. These features are well-suited to support robust chromosome segregation.

Copyright 
The copyright holder for this preprint is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. All rights reserved. No reuse allowed without permission.
Back to top
PreviousNext
Posted January 26, 2017.
Download PDF

Supplementary Material

Email

Thank you for your interest in spreading the word about bioRxiv.

NOTE: Your email address is requested solely to identify you as the sender of this article.

Enter multiple addresses on separate lines or separate them with commas.
Mapping load-bearing in the mammalian spindle reveals local kinetochore-fiber anchorage that provides mechanical isolation and redundancy
(Your Name) has forwarded a page to you from bioRxiv
(Your Name) thought you would like to see this page from the bioRxiv website.
Share
Mapping load-bearing in the mammalian spindle reveals local kinetochore-fiber anchorage that provides mechanical isolation and redundancy
Mary Williard Elting, Manu Prakash, Dylan B. Udy, Sophie Dumont
bioRxiv 103572; doi: https://doi.org/10.1101/103572
Digg logo Reddit logo Twitter logo CiteULike logo Facebook logo Google logo Mendeley logo
Citation Tools
Mapping load-bearing in the mammalian spindle reveals local kinetochore-fiber anchorage that provides mechanical isolation and redundancy
Mary Williard Elting, Manu Prakash, Dylan B. Udy, Sophie Dumont
bioRxiv 103572; doi: https://doi.org/10.1101/103572

Citation Manager Formats

  • BibTeX
  • Bookends
  • EasyBib
  • EndNote (tagged)
  • EndNote 8 (xml)
  • Medlars
  • Mendeley
  • Papers
  • RefWorks Tagged
  • Ref Manager
  • RIS
  • Zotero
  • Tweet Widget
  • Facebook Like
  • Google Plus One

Subject Area

  • Cell Biology
Subject Areas
All Articles
  • Animal Behavior and Cognition (1544)
  • Biochemistry (2500)
  • Bioengineering (1757)
  • Bioinformatics (9727)
  • Biophysics (3928)
  • Cancer Biology (2990)
  • Cell Biology (4235)
  • Clinical Trials (135)
  • Developmental Biology (2653)
  • Ecology (4129)
  • Epidemiology (2033)
  • Evolutionary Biology (6931)
  • Genetics (5243)
  • Genomics (6531)
  • Immunology (2207)
  • Microbiology (7012)
  • Molecular Biology (2782)
  • Neuroscience (17410)
  • Paleontology (127)
  • Pathology (432)
  • Pharmacology and Toxicology (712)
  • Physiology (1068)
  • Plant Biology (2515)
  • Scientific Communication and Education (647)
  • Synthetic Biology (835)
  • Systems Biology (2698)
  • Zoology (439)