Effects of cryopreservation on meiotic spindles of oocytes and its dynamics after thawing: clinical implications in oocyte freezing - a review article
Effects of cryopreservation on meiotic spindles of oocytes and its dynamics after thawing: clinical implications in oocyte freezing - a review article
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DOI：
10.1016/s0303-7207(03)00070-4
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发表时间：
2003-04-28
影响因子：
4.1
通讯作者：
Lee, TY
中科院分区：
文献类型：
--
作者：
Chen, SU;Lien, YR;Lee, TY
胚胎冷冻是一种成功的做法，但卵母细胞冷冻保存以前取得了较差的效果。这主要是由于存活率、受精率和发育率低。卵母细胞与胚胎的主要区别是质膜的特征，皮质颗粒的存在，在减数分裂II中期与纺锤体系统。此外，卵母细胞必须在适当的时间由精子受精。为了提高卵母细胞的存活率，采用改良的慢速冷冻法，增加蔗糖浓度，可以使卵母细胞更充分地冷冻。玻璃化是防止冰晶形成的另一种方法。胞浆内单精子注射用于克服皮质颗粒释放可能导致的精子硬化。减数分裂纺锤体的微管易受温度变化的影响而脱落。冻存卵母细胞解冻后立即表现出严重的微管紊乱。纺锤体结构紊乱的卵母细胞受精可导致染色体非整倍体、二雌体和卵裂停滞。孵育后，微管以时间依赖的方式恢复。在适当的孵育和授精时间后，冷冻保存的卵母细胞的正常受精和发育得到改善，与纺锤体的恢复相容。随着卵母细胞存活率、受精率和卵裂率的提高，卵母细胞冷冻保存将发挥重要作用。(C)2003爱思唯尔科学爱尔兰有限公司保留所有权利。
Embryo freezing has been a successful practice, but oocyte cryopreservation formerly achieved poorer results. This was mainly due to low rates of survival, fertilization, and development. The major dissimilarities for oocytes to embryos are the character of the plasma membrane, the presence of cortical granules, at the metaphase of meiosis II with the spindle system. In addition, the oocytes must be fertilized by sperm at the appropriate time. To improve the survival rate, a refined slow freezing method with increased sucrose concentration would dehydrate oocytes more sufficiently. Vitrification is another approach to prevent ice crystal formation. Intracytoplasmic sperm injection is used to overcome possible zona hardening from the release of cortical granules. The microtubules of meiotic spindles are vulnerable to the thermal changes and would depolymerize. Cryopreserved oocytes exhibited serious disturbances of the microtubules immediately after thawing. Fertilization of oocytes with disorganized spindles could lead to chromosomal aneuploidy, digyny, and arrest of cleavage. After incubation, the microtubules would repolymerize in a time-dependent way. Normal fertilization and development of cryopreserved oocytes improved after appropriate incubation and timing of insemination, compatible with recovery of the spindles. With the improvement of survival, fertilization, and cleavage, oocyte cryopreservation would gain an imperative role. (C) 2003 Elsevier Science Ireland Ltd. All rights reserved.