Drosophila uses a tripod gait across all walking speeds, and the geometry of the tripod is important for speed control

  1. Chanwoo Chun
  2. Tirthabir Biswas
  3. Vikas Bhandawat  Is a corresponding author
  1. Duke University, United States
  2. Janelia Research Campus, Howard Medical Institute, United States
  3. Drexel University, United States

Abstract

Changes in walking speed are characterized by changes in both the animal's gait and the mechanics of its interaction with the ground. Here we study these changes in walking Drosophila. We measured the fly's center of mass (CoM) movement with high spatial resolution and the position of its footprints. Flies predominantly employ a modified tripod gait that only changes marginally with speed. The mechanics of a tripod gait can be approximated with a simple model – angular and radial spring-loaded inverted pendulum (ARSLIP) – which is characterized by two springs of an effective leg that become stiffer as the speed increases. Surprisingly, the change in the stiffness of the spring is mediated by the change in tripod shape rather than a change in stiffness of the individual leg. The effect of tripod shape on mechanics can also explain the large variation in kinematics among insects, and ARSLIP can model these variations.

Data availability

Data is available on Dryad under doi:10.5061/dryad.m63xsj41g and Github https://github.com/vbhandawat/FlyTripod_eLife_2021/

The following data sets were generated

Article and author information

Author details

  1. Chanwoo Chun

    Department of Biology, Duke University, Durham, United States
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-0759-6727
  2. Tirthabir Biswas

    Janelia Research Campus, Howard Medical Institute, Ashburn, United States
    Competing interests
    The authors declare that no competing interests exist.
  3. Vikas Bhandawat

    Biomedical Engineering, Sciences and Health Systems, Drexel University, Philadelphia, United States
    For correspondence
    vb468@drexel.edu
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-2608-0403

Funding

National Science Foundation (IOS-1652647)

  • Vikas Bhandawat

National Institute on Deafness and Other Communication Disorders (RO1DC015827)

  • Vikas Bhandawat

National Institute of Neurological Disorders and Stroke (RO1NS097881)

  • Vikas Bhandawat

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

Reviewing Editor

  1. Gordon J Berman, Emory University, United States

Publication history

  1. Received: December 17, 2020
  2. Accepted: January 22, 2021
  3. Accepted Manuscript published: February 3, 2021 (version 1)
  4. Version of Record published: March 4, 2021 (version 2)

Copyright

© 2021, Chun 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.

Metrics

  • 1,906
    Page views
  • 159
    Downloads
  • 2
    Citations

Article citation count generated by polling the highest count across the following sources: Crossref, PubMed Central, Scopus.

Download links

A two-part list of links to download the article, or parts of the article, in various formats.

Downloads (link to download the article as PDF)

Open citations (links to open the citations from this article in various online reference manager services)

Cite this article (links to download the citations from this article in formats compatible with various reference manager tools)

  1. Chanwoo Chun
  2. Tirthabir Biswas
  3. Vikas Bhandawat
(2021)
Drosophila uses a tripod gait across all walking speeds, and the geometry of the tripod is important for speed control
eLife 10:e65878.
https://doi.org/10.7554/eLife.65878

Further reading

    1. Neuroscience
    Camila Vesga-Castro et al.
    Review Article

    Over the last few years, there has been growing interest in measuring the contractile force (CF) of engineered muscle tissues to evaluate their functionality. However, there are still no standards available for selecting the most suitable experimental platform, measuring system, culture protocol, or stimulation patterns. Consequently, the high variability of published data hinders any comparison between different studies. We have identified that cantilever deflection, post deflection, and force transducers are the most commonly used configurations for CF assessment in 2D and 3D models. Additionally, we have discussed the most relevant emerging technologies that would greatly complement CF evaluation with intracellular and localized analysis. This review provides a comprehensive analysis of the most significant advances in CF evaluation and its critical parameters. In order to compare contractile performance across experimental platforms, we have used the specific force (sF, kN/m2), CF normalized to the calculated cross-sectional area (CSA). However, this parameter presents a high variability throughout the different studies, which indicates the need to identify additional parameters and complementary analysis suitable for proper comparison. We propose that future contractility studies in skeletal muscle constructs report detailed information about construct size, contractile area, maturity level, sarcomere length, and, ideally, the tetanus-to-twitch ratio. These studies will hopefully shed light on the relative impact of these variables on muscle force performance of engineered muscle constructs. Prospective advances in muscle tissue engineering, particularly in muscle disease models, will require a joint effort to develop standardized methodologies for assessing CF of engineered muscle tissues.

    1. Genetics and Genomics
    2. Neuroscience
    Junhao Li et al.
    Research Article

    Two epigenetic pathways of transcriptional repression, DNA methylation and Polycomb repressive complex 2 (PRC2) are known to regulate neuronal development and function. However, their respective contributions to brain maturation are unknown. We found that conditional loss of the de novo DNA methyltransferase Dnmt3a in mouse excitatory neurons altered expression of synapse-related genes, stunted synapse maturation, and impaired working memory and social interest. At the genomic level, loss of Dnmt3a abolished postnatal accumulation of CG and non-CG DNA methylation, leaving adult neurons with an unmethylated, fetal-like epigenomic pattern at ~222,000 genomic regions. The PRC2-associated histone modification, H3K27me3, increased at many of these sites. Our data support a dynamic interaction between two fundamental modes of epigenetic repression during postnatal maturation of excitatory neurons, which together confer robustness on neuronal regulation.