中文摘要：

目的考察小鼠孤雌胚胎H3K27乙酰化模式与体内胚胎的差异,探究表观遗传模式对孤雌胚发育的影响。方法利用SrCl2激活卵母细胞,获得植入前各时期孤雌胚胎,并统计胚胎发育率;小鼠注射孕马血清激素（Pregnant Mare Serum Gonadotrophin,PMSG）和人绒毛膜促性腺激素（Human Chorionic Gonadotropin,hCG）超排后合笼,在不同发育时间采用体内冲胚的方法获得体内各时期胚胎;将获得的各期各类胚胎用H3K27乙酰化抗体与特异性位点结合,与连接有FITC荧光基团的二抗共同孵育,利用激光共聚焦显微镜检测荧光强度,获得小鼠植入前各时期孤雌胚和体内胚组蛋白H3K27乙酰化模式。结果用SrCl2激活成熟卵母细胞得到的孤雌胚的激活率和囊胚率分别为96.39%和69.54%,处于正常发育水平;孤雌胚H3K27乙酰化荧光强度从原核期相对较高的水平逐渐降低,2-细胞、4-细胞和8-细胞时期荧光强度都处于较低水平,到桑葚胚时期又突然升高,总体变化趋势和体内组先降低后升高的整体趋势一样,且原核期至8-细胞时期的荧光值孤雌胚高于体内胚,桑囊胚时期则相反;两组的H3K27乙酰化荧光强度值在原核期和桑葚胚时期差异不显著（P〉0.05）,在2-细胞、4-细胞、8-细胞和囊胚期差异显著（P〈0.01）。结论本研究表明小鼠孤雌胚H3K27乙酰化模式与体内胚的模式存在差异,可能是影响孤雌胚发育能力的重要原因之一。进一步的深入研究将对纠正小鼠孤雌胚乙酰化模式和提高孤雌胚发育能力具有重要意义。

英文摘要：

Objective To investigate the difference of the patterns of H3K27 acetylation between parthenogenetic embryos and in vivo mouse embryos,and explore the effect of epigenetic mode on parthenogenetic embryos development.Method Different period of parthenogenetic embryos were obtained by using strontium chloride activated mouse oocytes,and the developmental rates of these embryos were counted.After superovulation by injecting pregnant mare serum gonadotrophin and human chorionic gonadotropin,different period of embryos were collected by washing of uterus in vivo.These embryos were labeled by H3K27 acetylated antibody and then incubated with FITC fluorescent secondary antibody.The relative fluorescence intensities of these reprocessed parthenogenetic embryos and in vivo mouse embryos were detected by laser scanning confocal microscope.Result The activation rate and blastocyst rate of parthenogenetic embryos were 96.385 ± 0.385 and 69.54 ± 2.87,respectively.The fluorescence intensity of H3K27 acetylated parthenogenetic embryos performed a relatively high level at first and then significantly reduced during the periods of 2-cell,4-cell and 8-cell.The level of the fluorescence intensity increased rapidly in morula.The overall trend of the fluorescence intensity in parthenogenetic embryos was similar with in vivo.The relative fluorescence intensity of H3K27 acetylated parthenogenetic embryos was higher than in vivo from prokaryotic period to 8-cells,whereas the others were opposite.Additionally,significant differences were observed between parthenogenetic embryos and in vivo embryos in all periods（P 0.01） except in prokaryotic period and morula period（P 0.05）.Conclusion This study shows that the patterns of H3K27 acetylation in parthenogenetic embryos are different with in vivo mouse embryos,and this might be an important reason affecting the developmental ability of parthenogenetic embryos.Further study will be important for correcting the acetylation patterns and improving the viability of parthenogenetic embry