Diagrammatic description of epigenetic events during oocyte maturation. Non growing oocyte (NGO) has unmethylated DNA and histone in bovine oocyte. Histone lysines H3 and H4 are acetylated at this stage. DNA methylation is initiated in bovine growing oocytes while histone changes include deacetylation until the MII stage. At germinal vesicle stage (GV), DNA methylation reaches peak. In addition, histone is methylated at the GV stage in bovine oocyte. At metaphase 2 (MII), oocyte shows decline in DNA methylation while histones proteins are acetylated. This developed and modified according to (Sendžikaite and Kelsey, 2019; Wang et al., 2006).