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Biophysical Characterization of Flagellar Motor Functions
Published on: January 18, 2017
Nonlinear instability in flagellar dynamics: a novel modulation mechanism in sperm migration?
H Gadêlha1, E A Gaffney, D J Smith
1Centre for Mathematical Biology, Mathematical Institute, University of Oxford, UK. gadelha@maths.ox.ac.uk
Journal of the Royal Society, Interface
|May 14, 2010
Summary
Nonlinear mechanics reveal that internal forces in sperm flagella cause buckling, leading to complex waveforms and curved swimming. This nonlinear model is crucial for understanding sperm motility and other biological systems.
Area of Science:
- Biophysics
- Cell Biology
- Fluid Dynamics
Background:
- Cells and organisms utilize flagella and cilia for propulsion and motility, essential for various biological processes.
- Existing mathematical models of flagellum-fluid interaction are limited to linear or weakly nonlinear regimes, failing to capture physiological high curvatures.
Purpose of the Study:
- To investigate the impact of geometrical nonlinearity on flagellar mechanics, specifically focusing on the spermatozoon flagellum.
- To determine if nonlinear effects can explain complex flagellar waveforms and swimming behaviors observed in biological systems.
Main Methods:
- Development and analysis of a nonlinear mathematical model for flagellar mechanics.
- Simulation of flagellar behavior under physiologically relevant parameters.
Main Results:
- The nonlinear model predicts that internal forces induce flagellar compression, leading to buckling and symmetry-breaking bifurcations.
- This buckling results in complex changes to the flagellar waveform and swimming trajectory, invalidating linear theories.
- The emergent waveform causes curved swimming, even in symmetric systems, and is sensitive to head shape.
Conclusions:
- Nonlinear models are essential for accurately understanding the flagellar waveform in human sperm motility.
- These nonlinear models will be valuable for studying motile flagella and cilia across diverse biological systems.
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