[Differentially expressed long non-coding RNAs in spermatozoa with different fertilizing abilities].

OBJECTIVE: To search for conception capacity-related long non-coding RNAs (lncRNA) and explore their possible roles in fertilization. METHODS: We obtained 10 semen samples, 5 of high and the other 5 of low fertilizing ability, extracted large RNAs, established a cDNA library, and performed RNA sequencing with the HiSeq 2000 sequencing system. Using the bioinformatics method, we assembled and predicted lncRNAs, screened differentially expressed genes between the two groups by NOIseq, analyzed the lncRNAs with the box plot and volcano plot, and determined their expression patterns by hierarchical cluster analysis. We examined the functional classification of differentially expressed lncRNAs by pathway and gene ontology (GO) enrichment and predicted those of some lncRNAs by lncRNA-mRNA interaction analysis and intersection analysis with up- and down-stream cis-acting elements. RESULTS: A total of 147 1615 lncRNAs were identified in all the semen samples, including 463 596 novel ones and 8 019 known ones, with 4 052 differentially expressed lncRNAs, 985 upregulated and the other 3 067 downregulated. Box plot and volcano plot filtering analyses showed statistically significant differences in the expressions of the lncRNAs between the two groups, and so did hierarchical cluster analysis. GO functional annotations manifested the involvement of the differentially expressed lncRNAs in the metabolic process, biological regulation, membrane and organelle formation, and protein-nucleotide binding. Pathway analysis showed that the differentially expressed lncRNAs were related to transport and catabolism, cell motility, signaling molecular interactions, signaling transduction, and signaling pathways in the development and immune systems. The functions of the 5 lncRNAs predicted were shown to be associated with sperm motility, acrosomal reaction and signal transduction during fertilization. CONCLUSIONS: Differentially expressed lncRNAs may play an important role in fertilization and become biomarkers for the assessment of sperm quality.

[Characteristics of sperm donors and the eligibility rate of screening for sperm donation].

OBJECTIVE: To investigate the relationship of the characteristics of sperm donors with the results of screening and provide some reference for the screening of sperm donors. METHODS: We statistically analyzed the screening data about 12 362 sperm donors at the Guangdong Human Sperm Bank from January 2003 to June 2017 and the relationship of the eligibility rate of screening with the donors' age, education, occupation, marriage, and fatherhood. RESULTS: Of the 12 362 sperm donors, 3 968 (32.1%) met the standards of semen quality and 3 127 (25.3%) filled all the requirements of sperm donation. The eligibility rate of screening was 27.7% in the donors aged 20－24 years, 24.3% in those aged 25－29 years, 23.8% in those aged 30－34 years, and 17.5% in those aged =≥35 years (P < 0.01); 23.5% in the senior high school students, 24% in the junior college students, 25.9% in the undergraduates, and 30.3% in the postgraduates (P < 0.01); 29.3% in the students versus 22.9% in the others (P < 0.01), 41.5% in the married versus 20.7% in the unmarried (P < 0.01), and 45.6% in the fathers versus 20.9% in the childless husbands (P < 0.01). CONCLUSIONS: A higher eligibility rate of screening was found among the sperm donors aged <35 years or with a bachelor's or higher degree, particularly among students.

Sperm DNA damage has a negative effect on early embryonic development following in vitro fertilization.

Sperm DNA damage is recognized as an important biomarker of male infertility. To investigate this, sperm DNA damage was assessed by the sperm chromatin dispersion (SCD) test in semen and motile spermatozoa harvested by combined density gradient centrifugation (DGC) and swim-up in 161 couples undergoing in vitro fertilization (IVF). Semen analysis and sperm DNA damage results were compared between couples who did or did not achieve pregnancy. The sperm DNA damage level was significantly different between the two groups (P < 0.05) and was negatively correlated with IVF outcomes. Logistic regression analysis confirmed that it was an independent predictor for achieving clinical pregnancy. The effects of different levels of sperm DNA damage on IVF outcomes were also compared. There were significant differences in day 3 embryo quality, blastocyst formation rate, and implantation and pregnancy rates (P < 0.05), but not in the basic fertilization rate between the two groups. Thus, sperm DNA damage as measured by the SCD appears useful for predicting the clinical pregnancy rate following IVF.

Chloride channels are involved in sperm motility and are downregulated in spermatozoa from patients with asthenozoospermia.

Human spermatozoa encounter an osmotic decrease from 330 to 290 mOsm l-1 when passing through the female reproductive tract. We aimed to evaluate the role of chloride channels in volume regulation and sperm motility from patients with asthenozoospermia. Spermatozoa were purified using Percoll density gradients. Sperm volume was measured as the forward scatter signal using flow cytometry. Sperm motility was analyzed using computer-aided sperm analysis (CASA). When transferred from an isotonic solution (330 mOsm l-1 ) to a hypotonic solution (290 mOsm l-1 ), cell volume was not changed in spermatozoa from normozoospermic men; but increased in those from asthenozoospermic samples. The addition of the chloride channel blockers, 4,4'-diisothiocyanatostilbene-2,2'- isulfonic acid (DIDS) or 5-nitro-2-(3-phenylpropylamino) benzoic acid (NPPB) to the hypotonic solution caused the normal spermatozoa to swell but did not increase the volume of those from the asthenozoospermic semen. DIDS and NPPB decreased sperm motility in both sets of semen samples. The inhibitory effect of NPPB on normal sperm motility was much stronger than on spermatozoa from the asthenozoospermic samples. Both sperm types expressed ClC-3 chloride channels, but the expression levels in the asthenozoospermic samples were much lower, especially in the neck and mid-piece areas. Spermatozoa from men with asthenozoospermia demonstrated lower volume regulating capacity, mobility, and ClC-3 expression levels (especially in the neck) than did normal spermatozoa. Thus, chloride channels play important roles in the regulation of sperm volume and motility and are downregulated in cases of asthenozoospermia.

The reference values for semen parameters of 1213 fertile men in Guangdong Province in China.

Semen samples were collected from 1213 fertile men whose partners had a time-to-pregnancy (TTP) ≤12 months in Guangdong Province in Southern China, and semen parameters including semen volume, sperm concentration, total counts, motility, and morphology were evaluated according to the World Health Organization (WHO) 2010 guideline. All semen parameters analyzed were normal in ~62.2% of the total samples, whereas ~37.8% showed at least one of the semen parameters below normal threshold values. The fifth centiles (with 95% confidence intervals) were 1.3 (1.2-1.5) ml for semen volume, 20 × 10 6 (18×10 6 -20×10 6 ) ml-1 for sperm concentration, 40 × 10 6 (38×10 6 -44×10 6 ) per ejaculate for total sperm counts, 48% (47%-53%) for vitality, 39% (36%-43%) for total motility, 25% (23%-27%) for sperm progressive motility, 5.0% (4%-5%) for normal morphology. The pH values ranged from 7.2 to 8.0 with the mean ± standard deviation at 7.32 ± 0.17. No effects of age and body mass index were found on semen parameters. Occupation, smoking and alcohol abuse, varicocele appeared to decrease semen quality. Sperm concentration, but not sperm morphology, is positively correlated with TTP, whereas vitality is negatively correlated with TTP. Our study provides the latest reference values for the semen parameters of Chinese fertile men in Guangdong Province, which are close to those described in the new WHO guidelines (5 th Edition).

[Correlation between biological characteristics of volunteer donors and sperm parameters].

OBJECTIVE: To explore the correlation between the biological characteristics of volunteer donors and sperm parameters. METHODS: Sperm parameters were analyzed for 778 primary volunteer donors by CASA system with standard methods recommended by WHO including sperm concentration, motility rate, VCL, VSL, ALH, LIN, STR and BCF, and their biological characteristics were recorded. RESULTS: Of all the volunteer donors, students accounted for more than a third, 89.2 percent were under the age of 35 years, 71.6 percent between 166 and 175 cm in height, 91.7 percent of normal weight and 77.1 percent with college education. The median sperm concentration and motility rate were 107.00 x 10(6)/ml and 75 percent respectively. Age was weakly correlated with such semen indexes as concentration (r = 0.210, P = 0.000) , motility rate (r = 0.213, P = 0.000), volume (r = 0.165, P = 0.002), VAP (r = 0.259, P = 0.000), VSL (r = 0.281, P = 0.000), VCL (r = 0.190, P = 0.000), BCF (r = 0.243, P = 0.000) and LIN (r = 0.192, P = 0.000). The semen indexes of the 26-35 age group were a little better than those of the 20-25. Height showed no correlation to semen indexes. Education and occupation were somewhat related with other sperm parameters (P < 0.01) than ALH (P = 0.695/0.886). CONCLUSION: Age, occupation and education bear some correlation with sperm parameters except ALH, while height has none with any of them.