猪第一极体核物质参与卵母细胞受精及其胚胎发育的研究

Study on the Nucleus Materials of Porcine First Polar Body Participating in Fertilization of Oocyte and Embryonic Development

旨在探索猪卵母细胞第一极体核物质能否参与体外受精及其进一步的胚胎正常发育。第一极体(FPB)获自猪卵巢卵泡中卵丘卵母细胞复合体(COCs)体外成熟培养的MⅡ期卵母细胞。存活极体从成熟卵母细胞内分离后采用显微操作术注入去核卵母细胞胞质中。第一极体重组卵母细胞分别采用常规体外受精和单精子胞浆注射法进行受精,来自极体核重组的受精卵进行体外培养,观察和分析其进一步体外卵裂发育的能力。结果显示:极体显微操作重组的成功率约为80%,20%左右的重组卵母细胞于重组后的受精和发育培养过程中退化、崩解;常规体外受精和单精子注射后2-细胞卵裂率分别达到12.9%和29.8%。结论:猪第一极体核物质具有参与卵母细胞受精和进一步胚胎发育的能力。据此推测利用第一极体将有可能繁殖正常仔猪后代。

The aim of the present study was to explore whether the nuclei materials of first polar body （FPB）in porcine oocyte could participate in fertilization and further developed into normal porcine embryo in vitro. The FPBs in M Ⅱ oocytes were obtained by in vitro maturation of the Cumulus oocyte complexes （COCs） from ovary follicles. Live FPB was injected into an enucleated oocyte recipient by micromanipulation after it was isolated from mature oocyte. The oocytes reconstructed by FPB were fertilized by routine in vitro fertilization （IVF） or intracytoplasm sperm injection （ICSI）, the recombinant zygotes derived from FPBs were cultured in vitro to observe their ability of further developing in vitro. The results showed that successful rate of recombinant oocytes was as high as about 80%, only about 20% recombined oocytes were degenerated or disaggregated during the process of short culture and fertilization in vitro. Some of recombinant oocytes were successfully developed into two-cell, four-cell and eight-cell stage embryos, the cleavage rates of two-cell stage embryos were 12.9% and 29.8% after routine fertilization and ICSI, respectively. The conclusion was that the nuclei materials of porcine FPB could be able to participate in fertilization and further embryonic development. This might imply the possibility of reproducing normal porcine offspring by using FPBs in future.