fa علوم مولکولی Molecular Sciences تحقیقی Original article Infertility is defind as the inability to conceive after one year of regular unprotected sexual intercourse by a couple. Female infertility can have different causes that all factors can in somehow be influenced by genetic factors. Studies have shown that epigenetic changes play an important role in fetal development, oogenesis and spermatogenesis. During the growth of oocyte, follicular cells make a multilayer coating of granulosa cells. Granulosa cells are affected by gonadotropin hormones. The CYP₁₁A₁gene is one of the genes involved in the production of steroid hormones in luteinized granulosa cells. The CYP₁₁A₁ enzyme in the progesterone prodaction path way leads to the conversion of cholesterol to pregnenolon. Progesterone is an important steroid hormone that plays an important role in fertility and pregnancy. Histone modifications help to express the CYP₁₁A₁ gene. Trimethylation of Lysine 4 on histone H₃ (H₃K₄me₃) works to active transcription in the CYP₁₁A₁ promoterIn the present study, the level of methylation H₃K₄me₃ in regulation area of CYP₁₁A₁ gene in granulosa cells collected from the women with infertility problem and also from fertile women giving oocyte was investigated in Tabriz Jihad Daneshgahi infertilization center. To do this, the Chromatin Immunoprecipitation and then Real-Time PCR were used to investigate the level of methylation.According to the results of the present study, the level of methylation H₃K₄me₃ in the regulating area of CYP₁₁A₁gene in the given infertile people doesn&rsquo;t show significant difference in comparision with control group and no significant relationship was observed between methylation of histone in CYP₁₁A₁ promoter and number of follicles and oocyte.It is suggested that epigenetic changes in regulating area of CYP₁₁A₁ gene are not involved in the number of follicle and oocytes.&nbsp;&nbsp;&nbsp;&nbsp; <span dir="RTL"></span><br> <br> &nbsp; Granulosa cells,Histone methylation,steroidogenesis,CYP11A1 gene. 11 20 http://goums.ac.ir/jorjanijournal/browse.php?a_code=A-10-496-2&slc_lang=fa&sid=1 Saad Ghaderi ghaderibiology@gmail.com 10031947532846004270 10031947532846004270 No Department of biology, Islamic Azad University, Tabriz Branch, Tabriz, Iran Masoud Maleki Maleki.masoud@gmail.com 10031947532846004271 10031947532846004271 Yes Department of biology, Islamic Azad University, Tabriz Branch, Tabriz, Iran