PDF(Pubmed)
Abstract：
Oocyte cryopreservation is offered to women of various age groups for both health and social reasons. Oocytes derived from either controlled ovarian stimulation or in vitro maturation (IVM) are cryopreserved via vitrification. As maternal age is a significant determinant of oocyte quality, there is limited data on the age-related susceptibility of oocytes to the vitrification-warming procedure alone or in conjunction with IVM. In the present study, metaphase II oocytes obtained from 2, 6, 9, and 12 month old Swiss albino mice either by superovulation or IVM were used. To understand the association between maternal age and oocyte cryotolerance, oocytes were subjected to vitrification-warming and compared to non vitrified sibling oocytes. Survived oocytes were evaluated for mitochondrial potential, spindle integrity, relative expression of spindle checkpoint protein transcripts, and DNA double-strand breaks. Maturation potential and vitrification-warming survival were significantly affected (p < 0.001 and p < 0.05, respectively) in ovulated oocytes from the advanced age group but not in IVM oocytes. Although vitrification-warming significantly increased spindle abnormalities in ovulated oocytes from advanced maternal age (p < 0.01), no significant changes were observed in IVM oocytes. Furthermore, Bub1 and Mad2 transcript levels were significantly higher in vitrified-warmed IVM oocytes (p < 0.05). In conclusion, advanced maternal age can have a negative impact on the cryosusceptibility of ovulated oocytes but not IVM oocytes in mice.
摘要：
出于健康和社会原因，为不同年龄段的妇女提供卵母细胞冷冻保存。通过玻璃化冷冻保存来自受控卵巢刺激或体外成熟（IVM）的卵母细胞。由于母亲年龄是卵母细胞质量的重要决定因素，关于年龄相关的卵母细胞单独或联合使用玻璃化升温程序的易感性的数据有限。在本研究中,使用通过超排卵或IVM从2、6、9和12个月大的瑞士白化病小鼠获得的中期II卵母细胞。为了了解母亲年龄与卵母细胞冷冻耐受性之间的关系，对卵母细胞进行玻璃化加热，并与非玻璃化的同胞卵母细胞进行比较。评估存活的卵母细胞的线粒体电位，主轴完整性,纺锤体检查点蛋白转录本的相对表达，和DNA双链断裂。成熟潜能和玻璃化升温存活率在高龄组的排卵卵母细胞中受到显著影响(分别为p<0.001和p<0.05),而在IVM卵母细胞中没有影响。虽然玻璃化加温显著增加了高龄产妇排卵卵母细胞的纺锤体异常(p<0.01),在IVM卵母细胞中没有观察到显著的变化。此外，在玻璃化加温的IVM卵母细胞中,Bub1和Mad2转录物水平显著较高(p<0.05)。总之,高龄孕妇对小鼠排卵卵母细胞的冷冻敏感性有负面影响，但对小鼠IVM卵母细胞无影响。
