Aman R R, Parks J E
Department of Animal Science, Cornell University, Ithaca, New York 14853-4801.
Biol Reprod. 1994 Jan;50(1):103-10. doi: 10.1095/biolreprod50.1.103.
The purpose of this study was to evaluate effects of cooling and rewarming on the meiotic spindle apparatus of bovine oocytes. In experiment 1, in vitro-matured bovine oocytes were either maintained at 39 degrees C or cooled abruptly to 4 degrees C or approximately 25 degrees C. Immunohistochemical and DNA staining for visualization of microtubules and chromosomes, respectively, revealed an anastral, barrel-shaped spindle in bovine oocytes. Exposure to 4 degrees C for 10-20 min caused complete disappearance of the spindle. Some chromosome dispersion occurred after 60 min at 4 degrees C. After exposure to approximately 25 degrees C for 30 min, 90% of oocytes appeared abnormal, having either an abnormal spindle or no spindle. In experiment 2, oocytes cooled to either approximately 25 degrees C or 4 degrees C for 30 min were rewarmed directly or in steps for 15 or 60 min. Spindles did not return to normal in most oocytes regardless of cooling temperature or rewarming scheme. Step-wise rewarming was no more beneficial than direct rewarming. More of the oocytes rewarmed directly contained dispersed chromosomes as time at 39 degrees C increased.
本研究的目的是评估冷却和复温对牛卵母细胞减数分裂纺锤体装置的影响。在实验1中，体外成熟的牛卵母细胞要么维持在39℃，要么突然冷却至4℃或约25℃。分别用于微管和染色体可视化的免疫组织化学和DNA染色显示，牛卵母细胞中有一个无星、桶状纺锤体。暴露于4℃10 - 20分钟会导致纺锤体完全消失。在4℃60分钟后会出现一些染色体分散现象。暴露于约25℃30分钟后，90%的卵母细胞出现异常，要么有异常纺锤体，要么没有纺锤体。在实验2中，冷却至约25℃或4℃30分钟的卵母细胞直接复温或分步复温15或60分钟。无论冷却温度或复温方案如何，大多数卵母细胞的纺锤体都没有恢复正常。分步复温并不比直接复温更有益。随着在39℃的时间增加，直接复温的卵母细胞中更多含有分散的染色体。
