Methylation level of MEG3 and semen quality

Objective To study the relationship between semen quality and the methylation level of maternally expressed gene 3 (MEG3) in sperm. Methods We collected the general demographic data, semen samples and results of clinical semen analysis from 403 married men undergoing pre-conception examinations in March and April 2015 and March and April 2016. Using pyrosequencing, we quantitatively detected the methylation level at 8 CpG sites in the differentially methylated region of MEG3, and subjected the data obtained to variance analysis, Pearson correlation analysis, two-sample t-test and multivariate linear regression analysis. Results Both the individual and mean methylation levels at CpG sites 1－8 of MEG3 were correlated highly negatively with sperm concentration (P 0.05). The men with an abnormal sperm concentration exhibited significantly higher individual and mean methylation levels at the 8 CpG sites than those with a normal one (P Conclusions The imprinting gene MEG3 is involved in spermatogenesis and its methylation level may influence sperm concentration.