Identification of a Methylation Pattern in the SNRPN Gene Promoter and its Association with Semen Abnormality Among Iraqi Males

Abstract

Infertility considered as a multifactorial condition; the small nuclear ribonucleoprotein polypeptide N (SNRPN) gene is an imprinted gene. However, abnormal imprinting of this gene due to the methylation may result in abnormal function or silencing of the gene. Main aim of this study is to investigate the methylation present at the promoter of (SNRPN) gene and its role as a risk factor for male infertility. Sixty- three infertile males with age mean (32.28 ± 6.88 years) and 13 fertile males as a control age mean (34.07 ± 6.52 years) were investigated. Whole genomic DNA was extracted, DNA integrity was checked using β-globin gene as an internal control. The targeted region was amplified by polymerase chain reaction (PCR) technique. In addition, the SNRPN gene's promoter methylation was qualitatively detected using Real time polymerase chain reaction (qPCR) utilizing two sets of primers: methylated and un-methylated. Results reveled that all of the 63 infertile males were experiencing decrease in sperm concentration 9.42 ± 8.70 million/ml, reduced progressive motility 2.89 ± 5.45% as well as strange sperm morphology 27.06 ± 16.50%, while the values in the control group are normal. The results of the current investigation showed that the promoter of SNRPN was hypermethylated in some samples 22.7%, somewhat methylated in others 20.4%, and unmethylated in other samples 56.8% from infertile samples, while none of the 13 control samples had any methylation. These findings suggest that SNRPN gene may be associated with the negative changes in semen parameters, which could lead to male infertility.

Keywords

• Methylation
• SNRPN gene
• semen abnormality
• male infertility