The first stage of mitosis, during which the chromosomes condense and become visible, the nuclear membrane breaks down, and the spindle apparatus forms at opposite poles of the cell.

前期阶细胞减数分裂的第一个阶段，其间染色体浓缩且能被看见，核细胞膜衰弱。

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Under electron microscope, it was found that in some cells the nuclear membrane disappeared partly, chromatin became broadly granular and two centrioles were jointed by spindle fibers.

在透射电镜下观察到有细胞核膜消失，染色质变成粗颗粒状．中心粒一分为二，两中心粒之间还有纺锤丝牵引；

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