中文摘要：

供体细胞的同步化处理可能改变其表观遗传特性,进而影响胚胎的克隆效率。研究同步化处理对小鼠胎儿成纤维细胞（mouse embryonicf ibroblasts,MEFs）组蛋白H3K9甲基化、乙酰化及组蛋白H3K4单甲基化、三甲基化表达的影响。分离培养MEFs,增殖稳定的第3代MEFs分别用5mL/L血清饥饿处理4d或15mL/LDM-SO处理2d使细胞处于增殖抑制期,通过免疫组化染色和Image-J图像处理软件,相对定量比较不同处理情况下组蛋白H3K9甲基化、乙酰化和组蛋白H3K4单甲基化、三甲基化变化情况。Ki-67染色检测结果表明,两种同步化处理可使细胞处于G0期或G1期。DMSO处理使MEFs组蛋白H3K9乙酰化表达水平升高,而5mL/L血清饥饿处理则使其表达水平下降;此外,两种同步化处理均导致组蛋白H3K9甲基化和H3K4单甲基化表达下降,但不影响组蛋白H3K4三甲基化的表达水平。研究结论表明：同步化处理可改变MEFs组蛋白乙酰化和甲基化表达水平,进而有可能影响胚胎克隆效率。

英文摘要：

Synchronizion of donor cell cycle might affect epigenetic pattern of donor cells,which might have a further impact on the efficiency of embryo cloning.In this study,the effect of serum starvation or DMSO on histone H3K9 methylation,acetylation and H3K4 single-methylation,triple-methylation in mouse embryo fibroblasts （MEFs） was studied.MEFs at the third passages were synchronized by treating with 5 mL/L serum for 4 days or 15 mL/L DMSO for 2 days.Histone H3K9 methylation,acetylation and H3K4 single-methylation,triple-methylation were detected by fluorescence microscope and analyzed by Image-J image processing software.Ki-67 staining showed that both serum starvation and DMSO were efficient in synchronizing cell into G0 or G1 stage of cell cycle.Compared with the control groups,the H3K9 acetylation in the serum starvation groups was significantly reduced,while H3K9 acetylation in the DMSO groups was remarkably increased.In addition,both serum starvation and DMSO treatment reduced the histone H3K4 single-methylation and H3K9 methylation,but H3K4 triple-methylation was not changed.Thus,the results clearly proved that synchronization treatment obviously changed histone methylation and acetylation in MEFs,which might further affect the cloning efficiency of embryos.