中文摘要：

为了解水牛卵母细胞和体外受精（IVF）胚胎早期发育过程中端粒酶的活性变化,本研究利用端粒重复序列扩增法（TRAP）进行了水牛未成熟卵母细胞,成熟卵母细胞和2～4细胞,8～16细胞,桑椹胚以及囊胚各阶段的早期胚胎端粒酶活性的测定。依据电泳条带在成像系统下的光密度值,计算端粒酶的相对活性（RTA）。结果发现,未成熟卵母细胞端粒酶活性比成熟卵母细胞高（P〈0.05）,受精后2～4和8～16细胞胚胎端粒酶活性相对较低,桑椹胚端粒酶活性明显升高（P〈0.05）,囊胚阶段达到最高水平。通过对水牛不同发育阶段胚胎细胞数计数及单细胞相对端粒酶活性的分析比较结果显示,卵母细胞的单细胞端粒酶活性最高,囊胚阶段的最低。单细胞端粒酶活性从未成熟卵母细胞到IVF囊胚阶段呈逐渐降低的趋势。这些结果表明,水牛卵母细胞及早期胚胎的端粒酶活性变化与其成熟、发育阻断及全能性的逐步降低有关。

英文摘要：

The objective of this study was to examine the telomerase activity in swamp buffalo oocytes and early embryos derived from in vitro fertilization（IVF）.The telomerase activity of immature and matured oocytes,IVF embryos at the 2-4,8-16 cell,morula and blastocyst stages was assayed using a telomere repeat amplification protocol（TRAP）.The telomerase activity was higher in the immature oocytes than that in the matured oocytes（P〈 0.05）.After in vitro fertilization,the telomerase activity decreased as the zygotes cleaved to the 2-4 cell and 8-16 cell stages,increased again when the embryos developed to the morula stage（P〈 0.05）,and reached the highest level at the blastocyst stage.When the telomerase activity was calculated on the individual cell,telomerase activity declined gradually as the immature oocytes matured to Metaphase II and developed to the blastocyst stage after in vitro fertilization.These results indicate that the changes of telomerase activity in the buffalo oocytes and early embryos are related to their maturation,embryonic developmental block and totipotency decline during the embryogenesis.