en زیست شناسی مولکولی Molecular biology پژوهشي Research <p><strong>Background</strong>: Vitrification of oocytes is a fast-freezing technique, which may affect the quality of the human oocyte, and consequently affects the embryo development, pregnancy and birth. The aim of the current study was to investigate the consequence of <em>in-vitro</em> vitrification on maturation status of immature human oocytes, additionally, expression levels of stress, and apoptosis related genes.</p> <p><strong>Materials and Methods</strong>: The total of 213 human immature oocytes which routinely discarded from assisted reproduction clinics were collected and divided into two groups including: (I) fresh germinal vesicle (GV) oocytes (n=106) (matured <em>in-vitro </em>&nbsp;(fIVM) , and&nbsp; (II) GV oocytes (n=107) that initially vitrified, then matured in&nbsp; <em>in-vitro</em> (vIVM). After 36 hours of incubation, the oocytes were evaluated for nuclear maturation and expression level of DNA methyltransferase (DNMT1), stress related genes (Sod1 and Hsp70), and apoptotic related genes (Bax and Bcl-2) by quantitative Real-Time PCR.</p> <p><strong>Results</strong>: Oocyte maturation rates were reduced in vIVM compared to fIVM oocytes (<em>P=</em>0.001). The expression of stress (Sod1 and Hsp70), and apoptotic-related genes (Bax and Bcl-2) in vIVM were significantly higher compared to the fIVM group. Additionally, pro-apoptotic gene up-regulated 4.3 times more than anti-apoptotic gene in vIVM oocyte. However, <em>DNMT1</em> gene expression was reduced in vIVM oocyte (<em>P = </em>0.047).</p> <p><strong>Conclusions</strong>: The low survival rate of vitrified <em>In-vitro</em> matured GV oocytes could definitely be explained by the alterations of their gene expression profile.&nbsp;</p> Apoptosis, Oocytes, Vitrification 27 33 http://rmm.mazums.ac.ir/browse.php?a_code=A-10-617-2&slc_lang=en&sid=1 Abbas Shahedi عباس شاهدی abas_shahedi2006@yahoo.com 10031947532846006600 10031947532846006600 No Department of Biology and Anatomical Sciences, Shahid Sadoughi University of Medical Sciences , Yazd, Iran Ahmad Hosseini احمد حسینی Prof_Hosseini@yahoo.com 10031947532846006601 10031947532846006601 No Cellular and Molecular Biology Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran Mohammad Ali Khalili محمد علی خلیلی khalili@ssu.ac.ir 10031947532846006602 10031947532846006602 No Research and Clinical Center for Infertility, Shahid Sadoughi University of Medical Sciences, Yazd, Iran Farshid Yeganeh فرشید یگانه fyeganeh@sbmu.ac.ir 10031947532846006603 10031947532846006603 Yes Department of Immunology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran. گروه ایمونولوژی