Raha Favaedi - Department of Genetics, Reproductive Biomedicine Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran
Maryam Shahhoseini - Department of Genetics, Reproductive Biomedicine Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran
Marjan Sabbaghian - Department of Andrology, Reproductive Biomedicine Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran
Mohammad Ali Sadighi Gilani - Department of Andrology, Reproductive Biomedicine Research Center, Royan Institute for Reproductive Biomedicine, ACECR, Tehran, Iran

Background: Through spermatogenesis sperm chromatin undergoes drastic changes can be remodeled and condensed. Various testis-specific or highly expressed histone variants exist during spermatogenesis and some of them have been reported to play a key role in chromatin remodeling. H1T and H1T2 (variants of linker histone H1), as well as TSH2B (an H2B variant) are contributed in chromatin condensation. Incorporation of these variants on chromatin facilitates the replacement of histones with transition proteins and protamins.Methods: The aim of this study was to investigate the incorporation of mentioned histone variants on chromatin of testes tissue of azoospermic infertile men referred to Royan Institute. For this respect, consent was obtained from patients according to local ethical approval then, samples were collected through ART procedure. Based on pathological features, tissue samples divided into following three groups: complete maturation arrest, sertoli cell only syndrome, and hypospermatogenesis as positive control (at least 30 samples in each group). Relative expression of H1T, H1T2 and TSH2B genes were measured by real time PCR. Also total levels of incorporated H1T, H1T2 and TSH2B were evaluated by chromatin ELISA.Result: Results showed significant decrease of mRNA expression of H1T, H1T2 and TSH2B in complete maturation arrest and sertoli cell only syndrome groups vs. hypospermatogenesis group (p< 0.05). Also, data of chromatin ELISA revealed all variants had decreased total levels on chromatin in both groups with spermatogenesis impairment vs. positive control (p < 0.05).Conclusion: These findings imply significant association between altered levels of testis specific histone variants with impairment of spermatogenesis and male infertility.

ELISA, Histone variants, Infertility, Spermatogenesis, Chromatine