This study aims to evaluate the expression of genes associated with the fertilisation potential and embryo development, sperm DNA fragmentation (SDF), and acrosome reaction in male partners of infertile couples with different sperm parameters compared to fertile men. First, male partners of infertile couples with abnormal (N = 25) and normal sperm parameters (N = 25), and fertile men (N = 10) were included in experimental groups I, II, and controls respectively. The mRNA levels of the Annexin A2 (ANXA2), Sperm protein 17 (SP17), Plasma serine protease inhibitor (SERPINA5), and Peroxiredoxin‐2 (PRDX2) genes and SDF were evaluated. To evaluate the maturity of the sperm and oxidative stress, the acrosome reaction, the lipid peroxidation, and total antioxidant were measured. As result, SP17 showed a significantly lower expression in both experimental groups. SERPINA5 was significantly down‐regulated in experimental group I that was aligned with the low rate of acrosome reaction. Significant overexpression of PRDX2 was found between experimental group II and controls. Significant higher rates of SDF were seen in both experimental groups compared to the controls. Finally, our data suggest that differentially gene expression of SP17 is a potential diagnostic biomarker in infertile men either with normal or abnormal sperm parameters. SDF is one of the causes of male infertility, independent of the sperm parameters.

Objective The purpose of this study was to investigate the cellular and molecular levels of apoptosis induction in three groups of male partners of infertile couples, one featuring subjects with normal sperm parameters and unexplained male infertility (UMI), one including men with abnormal sperm parameters, and one with fertile men as controls. Methods Twenty-five infertile men with abnormal sperm parameters and 25 men with UMI and normal sperm parameters were recruited as experimental group I and experimental group II; 25 fertile men were included as controls. The mRNA levels of Fas, Fas ligand, Caspase 8, Bax , and Bcl2 were measured in the three groups. The cellular rates of early and late apoptosis were assessed using annexin V and propidium iodide staining. Results The expression of Bax, Bcl2 , and the Bax/Bcl2 ratio in experimental group I was significantly higher than that in experimental group II and controls. However, the Bax/Bcl2 ratio was less than 1 among all groups. No significant difference was found among study groups regarding the gene expression of Fas, Fas ligand , and Caspase 8 . No significant difference was seen in early apoptotic rates of sperm among study groups. The highest number of necrotic sperm cells was detected in experimental group I. Conclusions The findings showed that the external pathways of apoptosis were not activated in the absence of external stimuli of sperm apoptosis in ejaculated sperm. Regardless of fertility status, apoptosis gene induction in the internal pathway was associated with abnormalities in sperm motility and/or morphology in men with abnormal parameters.

Semen parameters have been found to predict reproductive success poorly and are the most prevalent diagnostic tool for male infertility. There are few conflicting reports regarding the correlation of DNMT genes expression, mitochondrial DNA copy number (mtDNAcn) and deletion (mtDNAdel) with different sperm parameters. To investigate DNMT mRNA level, mtDNAcn and deletion in infertile men, with different sperm parameters, compared with fertile men, semen samples from 30 men with unknown male infertility and normal sperm parameters (experimental group I), 30 infertile patients with at least two abnormal sperm parameters (experimental group II) and 30 fertile normozoospermic men (control group) were collected. After semen analysis, total RNA and DNA were extracted. The isolated DNA was used for assessing the respective mtDNAcn and the presence of common 4977 bp deletion in mtDNA by applying real‐time quantitative PCR and multiplex PCR, respectively. Synthesized cDNA from total RNAs was used to quantify DNMT1, DNMT3A and DNMT3B transcripts in study groups by using real‐time quantitative reverse‐transcription PCR. Significantly higher proportions of mtDNAcn were found in experimental group II. DNMT1 was significantly downregulated in both experimental groups and 4977 bp deletion was not detected. Progressive motility and normal morphology were significantly and negatively correlated with mtDNAcn. A significant positive correlation was detected between sperm parameters and DNMT1 mRNA levels. In conclusion, infertile men with different sperm parameter qualities showed elevated mtDNA content. Abnormal sperm parameters associated with DNMT1 gene expression indicate the possibility of changes in some epigenetic aspects of spermatogenesis in subfertile men with different sperm parameters.