Computer-assisted beat-pattern analysis and the flagellar waveforms of bovine spermatozoa

Abstract

Plagued by hurdles in information extraction, handling, and processing, computer-assisted sperm analysis (CASA) systems have typically neglected the complex flagellar waveforms of spermatozoa, despite their defining role in cell motility. Recent developments in imaging techniques and data processing have produced significantly-improved methods of waveform digitisation. Here, we utilise these improvements to demonstrate that near-complete flagellar capture is realisable on the scale of hundreds of cells, and, further, that meaningful statistical comparisons of flagellar waveforms may be readily performed with widely-available tools. Representing the advent of high-fidelity computer-assisted beat-pattern analysis (CABA), we show how such a statistical approach can distinguish between samples using complex flagellar beating patterns rather than crude summary statistics. Dimensionality-reduction techniques applied to entire samples also reveal qualitatively-distinct components of the beat, and a novel data-driven methodology for the generation of representative synthetic waveform data is proposed.

Biological benefits of collective swimming of sperm in a viscoelastic fluid

“…A possible explanation derives from the observations is as follows. Sperm in highly viscoelastic fluid propel themselves via planar flagellar beating (Tung et al, 2017;Walker et al, 2020), while, sperm in low-viscosity fluid commonly rotate along the long axis while swimming. Sperm are also known to swim much closer to a solid surface in a highly viscoelastic fluid than in low viscosity fluid (Nosrati et al, 2015).…”

CiliaQ: a simple, open-source software for automated quantification of ciliary morphology and fluorescence in 2D, 3D, and 4D images

“…Our group has released an open-source software for automated, comprehensive characterization of motile cilia and flagella based on 2D light and fluorescence microscopy imaging [24]. Similar software solutions have been released by other groups [25,26]. However, such analysis approaches are not applicable for cilia in tissues and tissue culture.…”