培养过程中温度对猪卵母细胞发育的影响(脂滴部分)

猪成熟的卵母细胞在体外20℃和37℃的条件下,以M—199为培养基,以未培养的卵母细胞做对照,分别培养24和48小时,观察和分析不同温度下猪卵母细胞的发育以及超微结构的变化。结果表明,不同温度对细胞内脂滴的数量没有影响,对脂滴内容物的致密度无显著影响,但对脂滴大小有影响。与对照组比较,实验组的脂滴明显增大。在37℃培养时,脂滴的大小与时间呈正比,20℃时,则先增大后缩小。形态上的差别:20℃培养时一些细胞的部分脂滴出现相变现象,未见脂滴的外排;37℃时脂滴的变化不同。猪卵母细胞不耐低温,可能由于猪卵母细胞含有大量脂类,低温时由液晶态的脂类变成晶态,使细胞失去正常功能,甚至死亡。

THE EFFECTS OF TEMPERATURE ON THE DEVELOPMENT OF THE PORCINE OOCYTES CULTURED IN VITRO

Matured pig oocytes were cultured in vitro in TCM-199 media at 37℃ for 24 hr and 48 hr respectively. The control was the oocytes uncultured. The development and ultrastructure of oocytes were observed and analysed, the main purpose of the experiment was to know why the pig oocytes could not endure lowtemperatures. The results were as follows: The number and content density of lipid vesicles in cytoplasm were not effected obviously by low temperatures. Compared with the control, the size of lipid vesicles in oocytes cultured became larger. When oocytes were cultured at 37℃, the size of lipid vesicles increased with the time however, when cultured at 20℃, the size of lipid vesicles increased at first and then decreased. Phase transition of lipid appeared in lipid vesicles in oocytes cultured at 20℃, and the discharge of lipid vesicles was not seen as compared with oocytes cultured at 37℃