Wolfson Centre for Mathematical Biology, Mathematical Institute, University of Oxford, Oxford OX2 6GG, UK.
Published: June 2020
AI Article Synopsis
Article Abstract
Obstructed by hurdles in information extraction, handling and processing, computer-assisted sperm analysis systems have typically not considered in detail 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 digitization. Here, we use these improvements to demonstrate that near-complete flagellar capture is realizable 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, 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.
Unlabelled: Motile flagella (also called "motile cilia") play a variety of important roles in lower and higher eukaryotes, including cellular motility and fertility. Flagellar motility is driven by several species of the gigantic motor-protein complexes, flagellar dyneins, that reside within these organelles. Among the flagellar-dynein species, a hetero-dimeric dynein called "IDA f/I1" has been shown to be particularly important in controlling the flagellar waveform, and defects in this dynein species in humans cause ciliopathies such as multiple morphological abnormalities of the flagella and asthenoteratozoospermia.
The sperm mitochondrial sheath has proposed functions in structural support and energy production for motility. Here we define coiled coil domain containing protein 112, CCDC112, as crucial for male fertility, specifically in the assembly and function of the mitochondrial sheath. We unveiled a previously unrecognised process of epididymal mitochondrial sheath maturation.
Mutimo cylindricus gametes have two flagella with different structures : an anterior and a posterior flagellum. Their flagellar waveforms are regulated by calcium ions through various mechanisms, however the factors involved in this regulation remain largely unknown To elucidate the molecular basis underlying the difference between the two flagella, we performed a flagellar proteomic analysis of male M. cylindricus gametes.
Sperm capture techniques that immobilize sperm are crucial for analyzing individual sperm in assisted reproductive technologies like ICSI, but traditional methods often limit natural sperm movement.
This text introduces a new microfluidic device that captures sperm while allowing flagellar motion, utilizing their natural behavior to guide them into a capture zone.
By enabling free movement of the flagellum, this device enhances research accuracy on sperm dynamics and simplifies analysis, addressing past inconsistencies in sperm behavior studies.
Eukaryotic flagella collectively form metachronal waves that facilitate the ability to cause flow or swim. Among such flagellated and planktonic swimmers, large volvocine genera such as Eudorina, Pleodorina and Volvox form bundles of small male gametes (sperm) called "sperm packets" for sexual reproduction. Although these sperm packets reportedly have flagella and the ability to swim, previous studies on volvocine motility have focused on asexual forms and the swimming characteristics of sperm packets remain unknown.
