【作者】 王刚；

【导师】 谭景和；

【作者基本信息】 山东农业大学 ， 动物遗传育种与繁殖， 2009， 硕士

【摘要】 小鼠卵母细胞排卵后停留在MⅡ期,只有正常受精或有适当刺激孤雌激活后才恢复减数分裂。若MⅡ卵母细胞不受精或激活,就会发生老化。老化卵母细胞的主要特征是MPF活性下降,孤刺激活敏感性增加,发育能力下降。与输卵管内滞留一样,体外成熟卵母细胞也发生老化。然而,包括显微操作和体外受精在内的很多研究在操作前都往往需要对成熟卵母细胞进行一段培养,有可能会导致卵母细胞老化而降低发育能力。所以,我们必须找到合适的方法来抑制卵母细胞老化。本实验室已证明丙酮酸在抑制卵母细胞老化中起着重要作用。低温能够降低细胞代谢水平,因此我们认为低温对卵母细胞的老化可能具有抑制作用。我们研究了温度和丙酮酸相互作用对小鼠卵母细胞老化的抑制作用。结果表明:1、在相同温度下,高浓度丙酮酸(10.27mM或5.27mM)能明显抑制卵母细胞孤雌激活敏感性的增加。2、在相同丙酮酸浓度下,温度越低卵母细胞孤雌激活敏感性增加得越慢(5℃＜15℃＜25℃＜37℃)。3、在各温度下高浓度丙酮酸都能显著提高老化卵母细胞的胚胎发育能力(10.27mM＞5.27mM＞0.27mM)。25℃和15℃,卵母细胞在高浓度(10.27mM)丙酮酸中老化24h,胚胎发育能力与37℃、低浓度(0.27mM)丙酮酸中老化6h差异不显著。4、在高浓度丙酮酸中老化24h,25℃受精率比15℃受精率显著降低。5、5℃低温下老化24h卵母细胞微管解聚,并且不能恢复。6、高丙酮酸25℃老化24h,透明带发生硬化,并且皮质颗粒排布异常,造成受精率显著降低。总之,添加丙酮酸和适当低温相结合能够有效抑制小鼠卵母细胞老化。经过进一步研究此方法有可能用于其它动物及人医临床。更多还原

【Abstract】 In most mammals,matured oocytes are arrested at metaphase-Ⅱafter ovulation,and will not resume meiosis until they are activated by penetrating spermatozoa or other stimulations.If the MⅡoocytes are not fertilized or activated timely,they will occurs aging,the main features of the aging oocyte are the activity of MPF decline,sensitivity of activated increased,ability of development decreased.Like detention in the oviduct,in vitro culture of matured oocytes also led to oocyte aging.Many experimental designs in research involve culture of matured oocytes prior to micromanipulation or insemination.So the oocytes may occur the aging to reduce the subsequent capacity of the development.Therefore,it is necessary that we find a suitable way to inhibit the aging of oocytes.Our labortary has proved that Pyruvate plays an important role in inhibiting the aging of oocytes,the level of cell metabolism will decreased in Low temperature,so we believe that the low temperature may have inhibitory effects on the aging of oocytes.We studied the interaction between temperature and pyruvate on the aging of mouse oocytes.The results showed that:1 at the same temperature,the high concentration of pyruvate (10.27mM,5,27mM) compared to low concentrations of pyruvate(0.27mM), high concentrations can inhibit Oocytes sensitivity of activated to increase.2 in the same concentration of pyruvate,oocyte sensitivity of activated increased more slowly with the more lower temperature (5℃＜15℃＜25℃＜37℃).3 at various temperatures,high concentrations pyruvate can significantly improve the capacity of embryos developmental (10.27mM＞5.27mM＞0.27mM) after oocytes aging,oocytes age for 24h supplemented with high concentrations(10.27mM)of pyruvate at 25℃and 15℃,the capacity of embryonic development have no significant difference between supplemented with low concentration of pyruvate at 37℃for aging 6h.4、25℃compared to 15℃can cause the ability of fertilization of the aging oocytes to decline both supplemented with the high concentration(10.27mM) of pyruvate.5、5℃low temperature would cause the oocytes microtubule depolymerization,and can not be restored for aging 24h.6、after aging for 24 hours supplemented with high pyruvate at 25℃, zona occur hardening,and distribution of the cortical granules are abnormal, we thinked this cause the low rate of the fertilization.In short,in appropriate temperature supplemented with high concentration of pyruvate can effectively inhibit the aging of mouse oocytes, this method may be used for other animal and human clinical medicine with further study.更多还原