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Updated: Apr 16, 2026

Flow Cytometric Analysis of Biomarkers for Detecting Human Sperm Functional Defects
Published on: April 21, 2022
DNA hypomethylation predisposes sperm to DNA damage in individuals with varicocele
Mahsa Bahreinian1, Marziyeh Tavalaee, Homayon Abbasi
1Department of Reproductive Biotechnology at Reproductive Biomedicine Research Center, Royan Institute for Biotechnology, ACECR , Isfahan , Iran .
Abstract:
This study aimed to assess and compare global DNA methylation (GDM) between fertile men and infertile men with varicocele. In addition, we evaluated the correlations between DNA methylation with reactive oxygen species (ROS), protamine deficiency, and DNA integrity. Semen samples were collected from 44 men with grades II and III varicocele, and 15 fertile men for assessment of semen parameters, DNA methylation, DNA fragmentation, oxidative stress, and protamine deficiency. Samples were evaluated by the World Health Organization (WHO) criteria, immunostaining, the TUNEL assay, 2', 7'-dichlorodihydrofluorescein diacetate (DCFH-DA) staining, and chromomycin A3 (CMA3) staining. Semen parameters were significantly lower in individuals with varicocele compared to fertile men. The percentage of GDM and intensity of DCFH were reduced and the percentages of DCFH, TUNEL, and CMA3 positive sperm significantly increased in individuals with varicocele compared to fertile men. Correlation analysis revealed a negative significant relation between DNA methylation and DNA fragmentation, but not with the degree of protamine deficiency and ROS production. The results have shown that individuals with varicocele show increased DNA susceptibility to damage when DNA is hypomethylated. This phenomenon appears to be independent of ROS production.
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