Meiotic spindle dynamics in human oocytes following slow-cooling cryopreservation
Meiotic spindle dynamics in human oocytes following slow-cooling cryopreservation
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DOI：
10.1093/humrep/dep182
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发表时间：
2009-09-01
影响因子：
6.1
通讯作者：
Albertini, D. F.
中科院分区：
文献类型：
--
作者：
Bromfield, J. J.;Coticchio, G.;Albertini, D. F.
人类卵母细胞冷冻保存的需求在辅助生殖临床中不断增加，但仍然是一个实验性的程序。令人惊讶的是，很少有人知道冷冻保存对纺锤体-染色体相互作用和减数分裂纺锤体功能的恢复的影响。这些研究的目的是评估冷冻保存的人类中期II卵母细胞中减数分裂纺锤体重组和染色体排列的过程。将未冷冻的对照卵母细胞与解冻后0、1、2和3 h固定的冷冻卵母细胞进行比较。共聚焦显微镜分析卵母细胞，并进行三维图像分析，以评估纺锤体的完整性。冷冻导致纺锤体双极性和染色体排列的损失。解冻后1小时，大多数卵母细胞恢复纺锤体双极性和赤道染色体排列。然而，在2和3小时之间，观察到染色体排列的进行性丢失。进一步的分析表明，纺锤体长度和冷冻后移位的染色体数之间呈正相关。这种时间依赖性的染色体重新分配涉及从赤道板向外位移和保留在减数分裂spindle.Spindle解体引起的冷冻保存的表面迅速逆转，并在1小时内与染色体排列相协调，但不持续在以后的时间。
The demand for cryopreservation of human oocytes is increasing in assisted reproduction clinics and yet remains an experimental procedure. Surprisingly, little is known about the effects of cryopreservation on spindle-chromosome interactions and the recovery of meiotic spindle functionality. The goal of these studies was to evaluate the process of meiotic spindle reassembly and chromosome alignment in cryopreserved human metaphase II oocytes.Unfrozen control oocytes were compared with frozen oocytes fixed at 0, 1, 2 and 3 h after thawing. Oocytes were analysed by confocal microscopy and subjected to 3-dimensional image analysis to evaluate spindle integrity.Freezing resulted in a loss of spindle bipolarity and chromosome alignment. One hour following thawing, most oocytes recovered spindle bipolarity and equatorial chromosomal alignment. However, between 2 and 3 h, a progressive loss of chromosome alignment was observed. Further analysis revealed a positive correlation between spindle length and number of displaced chromosomes following freezing. This time-dependent redistribution of chromosomes involved outward displacement from the equatorial plate and retention at the surface of the meiotic spindle.Spindle disassembly incurred by cryopreservation is rapidly reversed and is coordinated with chromosome alignment within 1 h but is not sustained at later times.