猪不同直径卵泡中卵母细胞体外培养的成熟潜力

Maturation Competence of the Pig Oocytes from Different Diameters of Follicles

比较研究了猪卵巢表面直径 0 .5～ 1 mm、1～ 2 mm、2～ 6mm、>6mm卵泡中卵母细胞所处的生发泡阶段。结果表明 ,0 .5～ 1 mm卵泡中卵母细胞主要处于 GV- 期和 GV- 期 2个阶段 ,比例分别为 67.2 %和2 0 .6%;而 1～ 2 mm和 2～ 6mm直径卵泡中 ,卵母细胞大部分则处于 GV- 期 ,比例分别为 91 .9%和89.6%;>6mm直径卵泡中 ,卵母细胞逐渐发生老化 ,GV- 期比例仅为 53 .2 %,一部分处于 GV- 期和GVBD期。体外培养试验表明 ,1～ 2 mm卵泡中卵母细胞的体外成熟率比较低 ,其中一部分卵母细胞不能发生 GVBD( 2 5.1 %) ,另有一部分卵母细胞 ( 3 9.8%)达到第 1次减数分裂中期后 ,不能继续向前发育。培养 0～ 2 0 h时 ,添加 1 mmol/ L dbc AMP,能够显著抑制 1～ 2 mm和 2～ 6mm直径卵泡中卵母细胞发生 GVBD。培养 2 0 h后 ,去除 dbc AMP,显著增加了培养到 4 4h阶段的 M- 期比率。 dbc AMP主要是降低了培养 4 4h阶段 GV期阻滞的比率 ,而对 M- 期阻滞的比例没有影响。因此 ,dbc

The stages of oocytes germinal vesicles from follicles in diameters of 0.5 1 mm, 1 2 mm, 2 6 mm and bigger than 6 mm were compared in this experiment. Oocytes from 0.5 1 mm follicles were mainly at GV Ⅰ and GV Ⅱ, with proportions of 67.2% and 20.6% respectively. Whereas most of the oocytes from 1 2 mm(91.9%) and 2 6 mm(89.6%) were at GV Ⅱ. 53.2% of the oocytes from follicles bigger than 6 mm were at GV Ⅱ, the others were at GV Ⅳ and GVBD, indicative of their aging. In vitro maturation indicated that oocytes from 1 2 mm follicles had a lower maturation rate than that from 2 6 mm follicles. Among them, 25.1% couldn′t go to GVBD, 39.8% stopped at M Ⅰ. Addition of 1 mmol/L dbcAMP from 0 20 h of culture could effectively inhibit GVBD. Removal of dbcAMP in the following stages increased the maturation rate from both follicles and decreased the percentage of oocytes arrested at GV stage, but didn′t affect those arrested at M Ⅰ. So, the effect of dbcAMP may mainly act for synchronization of GVBD.