Length-dependent disassembly maintains four different flagellar lengths in Giardia

  1. Shane G McInally
  2. Jane Kondev
  3. Scott C Dawson  Is a corresponding author
  1. University of California, Davis, United States
  2. Brandeis University, United States

Abstract

With eight flagella of four different lengths, the parasitic protist Giardia is an ideal model to evaluate flagellar assembly and length regulation. To determine how four different flagellar lengths are maintained, we used live-cell quantitative imaging and mathematical modeling of conserved components of intraflagellar transport (IFT)-mediated assembly and kinesin-13-mediated disassembly in different flagellar pairs. Each axoneme has a long cytoplasmic region extending from the basal body, and transitions to a canonical membrane-bound flagellum at the 'flagellar pore'. We determined that each flagellar pore is the site of IFT accumulation and injection, defining a diffusion barrier functionally analogous to the transition zone. IFT-mediated assembly is length-independent, as train size, speed, and injection frequencies are similar for all flagella. We demonstrate that kinesin-13 localization to the flagellar tips is inversely correlated to flagellar length. Therefore, we propose a model where a length-dependent disassembly mechanism controls multiple flagellar lengths within the same cell.

Data availability

All data generated or analysed during this study are included in the manuscript and supporting files.

Article and author information

Author details

  1. Shane G McInally

    Department of Microbiology and Molecular Genetics, University of California, Davis, Davis, United States
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-6145-4581
  2. Jane Kondev

    Department of Physics, Brandeis University, Waltham, United States
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-7522-7144
  3. Scott C Dawson

    Department of Microbiology and Molecular Genetics, University of California, Davis, Davis, United States
    For correspondence
    scdawson@ucdavis.edu
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-0843-1759

Funding

National Institutes of Health (R01AI077571)

  • Scott C Dawson

National Institutes of Health (GM0007377)

  • Shane G McInally

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Reviewing Editor

  1. Gregory J Pazour, University of Massachusetts Medical School, United States

Publication history

  1. Received: May 23, 2019
  2. Accepted: December 18, 2019
  3. Accepted Manuscript published: December 19, 2019 (version 1)
  4. Version of Record published: January 30, 2020 (version 2)

Copyright

© 2019, McInally et al.

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.

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  1. Shane G McInally
  2. Jane Kondev
  3. Scott C Dawson
(2019)
Length-dependent disassembly maintains four different flagellar lengths in Giardia
eLife 8:e48694.
https://doi.org/10.7554/eLife.48694

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