CASA-Mot in mammals: an update

Abstract

Sperm motility is one of the most widely used parameters of sperm quality. Computer-aided sperm motility analysis (CASA-Mot) systems were developed to reduce the subjectivity of sperm motility assessment, and have had broad scientific and practical acceptance. In this review, the sources of variation and current applications of this technology and its relationships with other sperm quality tests are described in detail. Despite remarkable advances in the technique, there is still great need for standardisation in many species, and the numerous factors that affect the results make it difficult to provide universally accepted criteria for classifying semen samples based on sperm motility characteristics. The main fields for CASA-Mot include the study of male fertility and pathologies, evaluation of the effects of physical and chemical agents, improvement of epidemiological survey studies, more precise calculation of seminal doses for farm animals, realisation of basic studies about sperm function, improvement of sperm technologies such as cryopreservation and quality control analysis. Numerous relationships have been established between CASA-Mot and other sperm quality tests, although most of these parameters are complementary. Future CASA-Mot systems will probably be able to integrate several sperm quality parameters with motility.

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

“…We have demonstrated that such analysis, performed here automatically on large sample sizes totalling hundreds of swimmers, and incorporating information from 90% of the length of the flagellum, is realisable with readily-available imaging and computational techniques, and thus represents a viable framework for a new generation of detailed flagellar CASA, and more generally the advent of computer-assisted beat-pattern analysis (CABA). The introduction of traditional CASA has had a substantial impact in theriogenology, for example enabling systematic quality control and assurance in the livestock breeding industry [9], as well as fundamental cell science, with extensive fundamental studies of sperm function [11][12][13]. Further, the expansion into near-complete planar flagellar waveform capture offers the prospect of novel directions for the exploration of male gamete motility, and flagellated or ciliated organisms more generally.…”

“…However, the extensive user intervention still required for such packages as well as basic thresholding based techniques, for example by Smith et al [4] who reported on the beats of 36 swimmers, has to date largely restricted population-level computer-assisted sperm analysis (CASA) to head-based investigations [5][6][7][8] and assessments of flagellar morphology [9], with flagellar waveforms neglected. Despite such limitations, and its only partial acceptance in clinical diagnostics [10], CASA has also found extensive application in reproductive toxicology, quality assurance for semen marketing in livestock breeding, improvements in sperm technologies such as cryopreservation, and studies of basic sperm function [11][12][13].…”

Implementation of novel statistical procedures and other advanced approaches to improve analysis of CASA data

“…Researchers must be aware of some caveats, some of which have been explained in more depth in other articles in this special volume (Bompart et al 2018;Yániz et al 2018aYániz et al , 2018b AQ1 ; Yeste et al 2018). Adequate equipment and standardised protocols for sample preparation and image acquisition are compulsory, but details are frequently overlooked (e.g.…”

Optimization of CASA-Mot Analysis of Donkey Sperm: Optimum Frame Rate and Values of Kinematic Variables for Different Counting Chamber and Fields

“…Then, the sperm sequences are automatically analysed by the computer in a concise time [11]. Moreover, CASA-Mot systems provide a battery of kinematic quantitative parameters that define the sperm cell motility rather than the progressivity [12].…”