title: H3K27me3 may be associated with Oct4 and Sox2 in mouse preimplantation embryos.
abstract: As a core member of polycomb repressive complex 2, the transcription and enzyme activity of enhancer of zeste homolog 2 (Ezh2) is directly involved in the trimethylation of lysine 27 on histone H3. In this study, the fluorescence intensity of H3K27me3 in mouse in vivo morulae and blastocysts was compared by indirect immunofluorescence staining. We found that demethylation of H3K27me3 occurred during the blastocyst stage. Real-time polymerase chain reaction was performed to investigate Ezh2 expression in oocytes and in preimplantation embryos. Ezh2 expression peaked during the zygote stage and gradually decreased from the 2-cell stage, exhibiting an inverse pattern when compared with Oct4 and Sox2 mRNA in mouse preimplantation embryos. To understand the role of development-related genes on the transcription of mouse Ezh2, a promoter assay was performed in NIH/3T3 cells. Ezh2 expression was markedly suppressed by Oct4 and Sox2 alone in a dose-dependent manner, while Ezh2 promoter activity in co-transfection with Nanog, Klf-4, and c-Myc groups showed no significant change as compared with the control. Our data suggest that the demethylation of H3K27me3 is caused by the degressive expression and activity of Ezh2 in blastocysts, leading to increased expression of developmentally important transcription factors. We also observed negative effects of Oct4 and Sox2 on the transcription of Ezh2 and identified Oct4 and Sox2 as novel negative regulators of Ezh2 at the post-translation level in a mouse preimplantation embryo.
authors.affiliation: School of Biological Science and Food Engineering, Fuyang Teachers College, Key Laboratory of Embryo Development and Reproductive Regulation, Anhui Province, Fuyang, China.
authors.forename: F-R
authors.initials: FR
authors.lastname: Wu
authors.affiliation: School of Biological Science and Food Engineering, Fuyang Teachers College, Key Laboratory of Embryo Development and Reproductive Regulation, Anhui Province, Fuyang, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: School of Biological Science and Food Engineering, Fuyang Teachers College, Key Laboratory of Embryo Development and Reproductive Regulation, Anhui Province, Fuyang, China.
authors.forename: B
authors.initials: B
authors.lastname: Ding
authors.affiliation: School of Biological Science and Food Engineering, Fuyang Teachers College, Key Laboratory of Embryo Development and Reproductive Regulation, Anhui Province, Fuyang, China.
authors.forename: X-H
authors.initials: XH
authors.lastname: Lei
authors.affiliation: School of Biological Science and Food Engineering, Fuyang Teachers College, Key Laboratory of Embryo Development and Reproductive Regulation, Anhui Province, Fuyang, China.
authors.forename: J-C
authors.initials: JC
authors.lastname: Huang
authors.affiliation: School of Biological Science and Food Engineering, Fuyang Teachers College, Key Laboratory of Embryo Development and Reproductive Regulation, Anhui Province, Fuyang, China.
authors.forename: C-H
authors.initials: CH
authors.lastname: Wang
authors.affiliation: School of Biological Science and Food Engineering, Fuyang Teachers College, Key Laboratory of Embryo Development and Reproductive Regulation, Anhui Province, Fuyang, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Liu
authors.affiliation: School of Biological Science and Food Engineering, Fuyang Teachers College, Key Laboratory of Embryo Development and Reproductive Regulation, Anhui Province, Fuyang, China.
authors.forename: R
authors.initials: R
authors.lastname: Wang
authors.affiliation: School of Biological Science and Food Engineering, Fuyang Teachers College, Key Laboratory of Embryo Development and Reproductive Regulation, Anhui Province, Fuyang, China liwenyong@aliyun.com.
authors.forename: W-Y
authors.initials: WY
authors.lastname: Li
mesh_terms: D000818:Animals; D001755:Blastocyst / Q000378:metabolism*; D002454:Cell Differentiation; D000071221:Enhancer of Zeste Homolog 2 Protein; D044127:Epigenesis, Genetic; D018507:Gene Expression Regulation, Developmental; D006657:Histones / Q000378:metabolism*; D008745:Methylation; D051379:Mice; D009028:Morula / Q000378:metabolism*; D041681:NIH 3T3 Cells; D050814:Octamer Transcription Factor-3 / Q000235:genetics*; D009865:Oocytes / Q000378:metabolism; D063151:Polycomb Repressive Complex 2 / Q000235:genetics*; D011401:Promoter Regions, Genetic; D055748:SOXB1 Transcription Factors / Q000235:genetics*
chemical_list: D006657:Histones; D050814:Octamer Transcription Factor-3; C494174:Pou5f1 protein, mouse; D055748:SOXB1 Transcription Factors; C527783:Sox2 protein, mouse; D000071221:Enhancer of Zeste Homolog 2 Protein; C498410:Ezh2 protein, mouse; D063151:Polycomb Repressive Complex 2