Comparative study of Sperm Motility Analysis System and conventional microscopic semen analysis

FBXO24 modulates mRNA alternative splicing and MIWI degradation and is required for normal sperm formation and male fertility

Spermiogenesis is a critical, post-meiotic phase of male gametogenesis, in which the proper gene expression is essential for sperm maturation. However, the underFlying molecular mechanism that controls mRNA expression in the round spermatids remains elusive. Here, we identify that FBXO24, an orphan F-box protein, is highly expressed in the testis of humans and mice and interacts with the splicing factors (SRSF2, SRSF3, and SRSF9) to modulate the gene alternative splicing in the round spermatids. Genetic mutation of FBXO24 in mice causes many abnormal splicing events in round spermatids, thus affecting a large number of critical genes related to sperm formation that were dysregulated. Further molecular and phenotypical analyses revealed that FBXO24 deficiency results in aberrant histone retention, incomplete axonemes, oversized chromatoid body, and abnormal mitochondrial coiling along sperm flagella, ultimately leading to male sterility. In addition, we discovered that FBXO24 interacts with MIWI and SCF subunits and mediates the degradation of MIWI via K48-linked polyubiquitination. Furthermore, we show that FBXO24 depletion could lead to aberrant piRNA production in testes, which suggests FBXO24 is required for normal piRNA counts. Collectively, these data demonstrate that FBXO24 is essential for sperm formation by regulating mRNA alternative splicing and MIWI degradation during spermiogenesis.

Analysis of selected sperm samples by a computer-assisted system with high frame rate: A prospective study

Background and Aims

Due to the rapid motility of the selected sperm, sperm parameters cannot be accurately determined by the manual method. So, the application of a computer-assisted sperm analysis system with a high frame rate (HFR-CASA, 85 Hz) in sperm selection is investigated.

Methods

A total of 177 semen samples were collected for sperm selection with density gradient centrifugation. Then, the manual method and HFR-CASA method will be used to observe and analyze the sperm concentration, motility, and percentage of progressively motile sperm (PR) of the selected sperm samples. The quality control of sperm concentration was performed with microballoons. Two selected sperm samples were analyzed 10 times repeatedly to evaluate the accuracy of the HFR-CASA.

Results

The results of microballoons analyzed with the HFR-CASA were in control. The coefficients of variation of sperm concentration, motility, and PR from two selected sperm samples were all below 10%. The results of 177 selected sperm samples analyzed by the manual method and HFR-CASA showed that although there were significant positive correlations in sperm concentration, motility, and PR between them (p < 0.001), the manual method significantly underestimated sperm concentration (p = 0.002) but overestimated sperm motility and PR (p < 0.001). When sperm concentration was below 50 × 10⁶/mL, the manual method significantly overestimated sperm concentration (p < 0.05). However, when sperm concentration was more than 100 × 10⁶/mL, the manual method significantly underestimated sperm concentration (p < 0.001). Regardless of sperm concentration, the manual method consistently overestimated sperm motility and PR (p < 0.001). When sperm concentration was more than 20 × 10⁶/mL, there was no correlation in sperm PR between them (p > 0.05). When sperm concentration was below 50 × 10⁶/mL, the correct rate of captured sperm by the HFR-CASA was more than 98%.

Conclusion

The HFR-CASA method is more accurate than the manual method in analyzing the selected sperm samples.

The validity and reliability of computer-aided semen analyzers in performing semen analysis: a systematic review

Background

Computer-aided sperm analyzers (CASA) are currently used worldwide for semen analysis. However, there are doubts about their reliability to fully substitute the human operator. Therefore, this study aimed to systematically review the current literature comparing results from semen evaluation by both CASA-based and manual approaches.

Methods

A systematic screening of the literature was performed based on the PRISMA guidelines and by searching on PubMed, Scopus, and Embase databases.

Results

A total of 14 studies were included. Our results showed a high degree of correlation for sperm concentration and motility when analysis was performed either manually or by using a CASA system. However, CASA results showed increased variability in low (<15 million/mL) and high (>60 million/mL) concentration specimens, while sperm motility assessment was inaccurate in samples with higher concentration or in the presence of non-sperm cells and debris. Morphology results showed the highest level of difference, due to the high amount of heterogeneity seen between the shapes of the spermatozoa either in one sample or across multiple samples from the same subject.

Conclusions

Overall, our study suggests CASA systems as a valid alternative for the evaluation of semen parameters in clinical practice, especially for sperm concentration and motility. However, further technological improvements are required before these devices can one day completely replace the human operator. Artificial intelligence-based CASA devices promise to offer higher efficiency of the analysis and improve the reliability of results.

Effect of Lepidium meyenii on in vitro fertilization via improvement in acrosome reaction and motility of mouse and human sperm

PURPOSE

The direct effects of Lepidium meyenii (Maca) on sperm remain unclear. Herein, we examined the direct effect of Maca on in vitro fertilization.

METHODS

We examined the fertilization rate in a mouse model and the rate of acrosome reaction in sperm from transgenic mice expressing enhanced green fluorescent protein (EGFP) in a Maca extract-containing human tubal fluid (HTF) medium. Using human sperm, we assessed acrosome status via fluorescein isothiocyanate-conjugated peanut agglutinin (FITC-PNA) staining and performed detailed analysis using a sperm motility analysis system (SMAS).

RESULTS

In the mouse model, the fertilization rate in the Maca extract-containing HTF was significantly higher than that in the control medium. The acrosome reaction rate in sperm from transgenic mice expressing EGFP was also significantly higher in the Maca extract-containing HTF than that in the control medium. Similarly, a high acrosome reaction rate, identified via FITC-PNA staining of human sperm samples, was found in the Maca extract-containing HTF compared with that in the control medium. Human sperm motility in the Maca extract-containing HTF was also increased compared with that in the control medium as measured using an SMAS.

CONCLUSIONS

Maca improved in vitro fertilization rates by inducing an acrosome reaction and increasing sperm motility.

Inverse correlation between reactive oxygen species in unwashed semen and sperm motion parameters as measured by a computer-assisted semen analyzer

This study investigated the correlation between sperm motion parameters obtained by a computer-assisted semen analyzer and levels of reactive oxygen species in unwashed semen. In total, 847 patients, except for azoospermic patients were investigated. At the time of each patient's first consultation, semen parameters were measured using SMAS™ or CellSoft 3000™, and production of reactive oxygen species was measured using a computer-driven LKB Wallac Luminometer 1251 Analyzer. The patients were divided into two groups: reactive oxygen species - positive and negative. The semen parameters within each group were measured using one of the two computer-assisted semen analyzer systems and then compared. Correlations between reactive oxygen species levels and sperm motion parameters in semen from the reactive oxygen species - positive group were also investigated. Reactive oxygen species were detected in semen samples of 282 cases (33.3%). Sperm concentration (P < 0.01; P < 0.01), motility (P < 0.01; P < 0.05), and progressive motility (P < 0.01; P < 0.01) were markedly lower in the reactive oxygen species - positive group than in the reactive oxygen species - negative group. Among the sperm motion parameters in the reactive oxygen species - positive group, sperm concentration (P < 0.01; P < 0.01), motility (P < 0.05; P < 0.01), mALH (P < 0.05; P < 0.01), and progressive motility (P < 0.05; P < 0.01) also showed inverse correlations with the logarithmic transformed reactive oxygen species levels. Therefore, this study demonstrated that excessive reactive oxygen species in semen damage sperm concentration, motility, and other sperm motion parameters.

Evaluation of the sperm motility analyzer system (SMAS) for the assessment of sperm quality in infertile men

Eighty-one fresh semen samples were analyzed to compare the sperm parameters obtained using the new Sperm Motility Analysis System (SMAS; version 1.0, Kaga Electronics, Tokyo, Japan) with the CellSoft(TM) Series 3000 (CRYO Resources, New York, USA) computer-assisted semen analysis (CASA) system and conventional manual semen analysis, based on WHO guidelines.. Significant correlations of sperm concentration (p<0.0001) and sperm motility (p<0.0001) were observed between SMAS and manual semen analysis estimates. There were also significant correlations of sperm concentration (p=0.0003) and sperm motility (p<0.0001) between SMAS and CellSoft estimates. Significant correlations for motility-related parameters were demonstrated in sperm velocity (p<0.0001), and linearity (linear velocity (VSL) divided by curvilinear velocity (VCL)×100) (p<0.0001), amplitude of lateral head displacement (ALH) (p<0.0001), and beat/cross frequency (BCF) (p=0.0127), between SMAS and CellSoft estimates. In this study, we showed the usefulness of the new SMAS, which has high reliability in estimating sperm concentration, sperm motility, velocity and linearity compared with CellSoft. SMAS can be a promising alternative, providing cost-effective semen analysis with the utility of the CASA system.

Ablation of the scaffold protein JLP causes reduced fertility in male mice

The specific and efficient activation of mitogen-activated protein kinase (MAPK) signaling modules is mediated, at least in part, by scaffold proteins. c-Jun NH(2)-terminal kinase (JNK)-associated leucine zipper protein (JLP) was identified as a scaffold protein for JNK and p38 MAPK signaling modules. JLP is expressed nearly ubiquitously and is involved in intracellular signaling pathways, such as the G(alpha13) and Cdo-mediated pathway, in vitro. To date, however, JLP expression has not been analyzed in detail, nor are its physiological functions well understood. Here we investigated the expression of JLP in the mouse testis during development. Of the tissues examined, JLP was strongest in the testis, with the most intense staining in the elongated spermatids. Since the anti-JLP antibody used in this study can recognize both JLP and sperm-associated antigen 9 (SPAG9), a splice variant of JLP that has been studied extensively in primates, we also examined its expression in macaque testis samples. Our results indicated that in mouse and primate testis, the isoform expressed at the highest level was JLP, not SPAG9. We also investigated the function of JLP by disrupting the Jlp gene in mice, and found that the male homozygotes were subfertile. Taken together, these observations may suggest that JLP plays an important role in testis during development, especially in the production of functionally normal spermatozoa.