Quantification and identification of sperm subpopulations using computer-aided sperm analysis and species-specific cut-off values for swimming speed

Abstract

Motility is an essential characteristic of all flagellated spermatozoa and assessment of this parameter is one criterion for most semen or sperm evaluations. Computer-aided sperm analysis (CASA) can be used to measure sperm motility more objectively and accurately than manual methods, provided that analysis techniques are standardized. Previous studies have shown that evaluation of sperm subpopulations is more important than analyzing the total motile sperm population alone. We developed a quantitative method to determine cut-off values for swimming speed to identify three sperm subpopulations. We used the Sperm Class Analyzer ® (SCA) CASA system to assess the total percentage of motile spermatozoa in a sperm preparation as well as the percentages of rapid, medium and slow swimming spermatozoa for six mammalian species. Curvilinear velocity (VCL) cut-off values were adjusted manually for each species to include 80% rapid, 15% medium and 5% slow swimming spermatozoa. Our results indicate that the same VCL intervals cannot be used for all species to classify spermatozoa according to swimming speed. After VCL intervals were adjusted for each species, three unique sperm subpopulations could be identified. The effects of medical treatments on sperm motility become apparent in changes in the distribution of spermatozoa among the three swimming speed classes.Motility is an important characteristic of spermatozoa, especially flagellated spermatozoa. Because the ultimate goal of a spermatozoon is to fertilize an ovum, it must be motile and travel relatively long distances in internal fertilizers (Holt and van Look 2004). This type of motility is characteristic of freshly ejaculated mammalian spermatozoa, where the flagellum generates a symmetrical and low amplitude waveform that propels the spermatozoon in a relatively straight line (Turner 2003).The importance of sperm motility is highlighted further by the fact that measurement of this parameter is an essential criterion of most semen or sperm evaluations (Mocé and Graham 2008). One frequently encountered problem in subfertile or infertile males is a low population of motile spermatozoa (asthenozoospermia) (Mortimer 1994). Earlier studies have demonstrated a relationship between decreased sperm motility and decreased fertilization rates, which often requires resorting to assisted reproductive techniques to achieve fertilization (Turner 2003). Greater sperm motility also has been

Reproductive toxicity after levetiracetam administration in male rats: Evidence for role of hormonal status and oxidative stress

“…A 4× negative phase contrast objective combined with a phase contrast condenser was used to determine sperm motility and concentration via the Motility/Concentration module of the Sperm Class Analyzer ® version 5.4.0.1 software (Microptic S. L., Barcelona, Spain) at 25 frames/second. For motility analysis, 200 motile spermatozoa were analyzed as recommended [18, 19]. …”

Progesterone-induced Acrosome Exocytosis Requires Sequential Involvement of Calcium-independent Phospholipase A2β (iPLA2β) and Group X Secreted Phospholipase A2 (sPLA2)

“…Only a few studies presented kinetic data, mainly on a single cell basis, thus focusing on fast responding cells (54 -56). However, sperm population is very heterogeneous, and the presence of sperm subpopulations with different degrees of maturity after capacitation completion is well documented in human and mouse (57)(58)(59)(60)(61). At the population level, AR is a long lasting event occurring over 30 min (Fig.…”

A novel flush technique to simulate natural dispersal of spermatozoa in the female reproductive tract and expedite motility assessment of fresh ejaculated Merino (<i>Ovis aries</i>) sperm

“…Compared with the SUT, the FT resulted in higher values for the percentage non-progressive motile spermatozoa (44.41% ± 2.30% vs. 36.63% ± 2.29%, P = 0.019), and the percentage medium velocity motile spermatozoa (22.58% ± 1.20% vs. 15.90% ± 1.19%, P = 0.0002) ( Table 3). These differences were expected and could be attributed to the pre-selection of sperm subpopulations, because the SUT discriminates against slow-swimming and immotile spermatozoa (Marti et al, 2011;Maree & Van der Horst, 2013). In contrast, the FT allows for assessment of the entire sample, including all sperm motility subpopulations, thus presenting a more accurate profile of the raw semen.…”