We demonstrate a technique for investigating the energetics of flagella or cilia. We record the planar beating of tethered mouse sperm at high-resolution. Beating waveforms are reconstructed using Proper Orthogonal Decomposition of the centerline tangent-angle profiles. Energy conservation is employed to obtain the mechanical power exerted by the dynein motors from the observed kinematics. A large proportion of the mechanical power exerted by the dynein motors is dissipated internally by the motors themselves. There could also be significant dissipation within the passive structures of the flagellum. The total internal dissipation is considerably greater than the hydrodynamic dissipation in the aqueous medium outside. The net power input from the dynein motors in sperm from Crisp2-knockout mice is significantly smaller than in wildtype samples, indicating that ion-channel regulation by cysteine-rich secretory proteins (CRISPs) controls energy flows powering the axoneme.
Source data files for all results figures have been provided.Videos of the WT and KO mice sperm samples are available for public access and download from the Monash University Research Repository (Ref. 64: DOI: 10.26180/5f50562bb322b)MATLAB Codes used to analyze the data to produce the results in the manuscript are available for public access and download from the Monash University Research Repository (Ref. 64: DOI: 10.26180/14045816}
- Reza Nosrati
- Ranganathan Prabhakar
- Moira K O'Bryan
- Sameer Jadhav
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Animal experimentation: This study was peformed in strict accordance with the Australian Code of Practice for the Care and Use of Animals for Scientific Purposes. All of the animals were handled according to institutional animal care and use protocols approved by the Monash Animal Ethics committee (Approval # MARP/2014/084).
- Raymond E Goldstein, University of Cambridge, United Kingdom
- Received: August 27, 2020
- Accepted: April 29, 2021
- Accepted Manuscript published: April 30, 2021 (version 1)
© 2021, Nandagiri 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.