Effect of vitrification at the germinal vesicle stage on the global methylation status in

Effect of vitrification at the germinal vesicle stage on the global methylation status in mouse oocytes

subsequently matured in vitro

Yan Jie;Zhang Lu;Wang Tianren;Li Rong;Liu Ping;Yan Liying;Qiao Jie

【期刊名称】《中华医学杂志（英文版）》 【年(卷),期】2014(000)023

【摘要】Background It is still unclear whether the vitrification procedure itself is associated with the incidence of abnormal DNA methylation during oocytes vitrification.The purpose of this study was to evaluate the epigenetic profile of mouse oocytes,which went through vitrification either at a mature stage or at an immature stage following in vitro maturation (IVM) by analyzing the global DNA methylation.Methods Metaphase Ⅱ (M Ⅱ) stage and germinal vesicle (GV) stage oocytes were collected from adult female mice and were vitrified respectively.The M Ⅱ oocytes were assessed for cryo-survival and global DNA methylation.The GV oocytes were assessed for cryo-survival and only the surviving GV oocytes were cultured in vitro for subsequent assessment of global DNA methylation in mature oocytes.In vivo matured fresh M Ⅱ oocytes without undergoing vitrification were used as control.The level of global DNA methylation in the M Ⅱ oocytes was then examined by immunofluorescence using an anti-5-methylcytosine (anti-5-MeC) monoclonal antibody and fluorescein isothiocyanate