猪卵巢卵母细胞体外成熟及体外受精过程中皮质颗粒变化的研究

目的　研究猪皮质颗粒在体外成熟及体外受精过程中的变化 ,以及皮质颗粒与多精受精的关系。　方法　用异硫氰荧光素联接的花生四烯酸 (FITC- PNA)标记体外成熟不同时间及体外受精不同时间皮质颗粒。　结果　皮质颗粒在猪卵母细胞体外成熟过程中逐渐由皮质部向卵质膜下迁移 ,并在质膜下排布成单层。体外成熟过程中所排出的第 1极体也被 FITC- PNA所标记 ,说明第 1极体中含有皮质颗粒。在对不同体外成熟时间的卵母细胞进行授精时发现 ,皮质颗粒的释放速度与体外成熟时间呈正比例关系。为进一步证实皮质颗粒的排放速度与多精受精之间的关系 ,还进行了精子穿透实验。结果显示 ,体外成熟 48h的卵母细胞其多精受精率为 73% ,比体外成熟36 h(83% )、2 4h(80 % )的卵母细胞要低。并且进入卵子的精子数目 (1.7)比后两者 (分别为 3.1和 2 .9)的少。　结论　多精受精率与皮质颗粒释放的速度和数量的大小有关

STUDY ON CORTICAL GRANULES CHANGE OF PIG OOCYTES DURING IVM AND IVF

Objective To investigate the behavior of cortical granules(CGs) during IVM and IVF, and the relationship between CGs and polyspermy. Methods We used the FITC|PNA as a probe to label the different period of IVM and IVF pig oocytes. Results CGs migrate towards the cell membrane during IVM, and finally form a monolayer under the membrane. The first polar body can be labeled by FITC|PNA indicating that it contains CGs. After fertilization oocytes maured in vitro, the speed of CGs release is in proportion with maturation time. To confirm the relationship of CGs exocytosis speed with polyspermy, we tested the sperm penetration on the oocytes matured in vitro for different period of time. In oocytes matured in vitro for 48h, polyspermy ratio is 73%, and lower than that in 36h(83%)and 24h(80%). Number of penetrating sperm(1^7)in 48h matured oocytes is also lower than that in 36h(3^1)and 24h(2^9). Conclusion The polyspermy incidence has a direct relation with the speed of CGs exocytosis and its quantity.;