Siberian Branch, Russian Academy of Sciences, Institute of Cytology and Genetics, Novosibirsk, Russia.
Cell Biol Int. 2014 Apr;38(4):472-9. doi: 10.1002/cbin.10222. Epub 2014 Jan 6.
The bipolar spindle is a major cytoskeletal structure, which ensures an equal chromosome distribution between the daughter nuclei. The spindle formation in animal cells depends on centrosomes activity. In flowering plant cells the centrosomes have not been identified as definite structures. The absence of these structures suggests that plants assemble their spindle via novel mechanisms. Nonetheless, the cellular and molecular mechanisms controlling the cytoskeleton remodeling during the spindle development in plants are still insufficiently clear. This article describes the results of a comparative analysis of the microtubular cytoskeleton dynamics during assembly of the second division spindle in tobacco microsporocytes with the normal and deformed nuclei. According to our observations, the bipolar spindle fibres are formed from short arrays of the disintegrated perinuclear cytoskeleton system, the perinuclear microtubular band. The microsporocytes of polyploid tobacco plants with deformed nuclei entirely lack this cytoskeleton structure. In such type of cells the overall prometaphase events are blocked, and the assembly of second division spindles is completely arrested.
双极纺锤体是一种主要的细胞骨架结构，它确保了子核之间染色体的均等分配。动物细胞的纺锤体形成依赖于中心体的活性。在开花植物细胞中，中心体尚未被确定为明确的结构。这些结构的缺失表明植物通过新的机制组装它们的纺锤体。尽管如此，控制植物纺锤体发育过程中细胞骨架重塑的细胞和分子机制仍然不够清楚。本文描述了对烟草小孢子母细胞中正常和畸形核第二分裂纺锤体组装过程中微管细胞骨架动力学进行比较分析的结果。根据我们的观察，双极纺锤体纤维是由解体的核周细胞骨架系统，即核周微管带的短阵列形成的。具有畸形核的多倍体烟草小孢子母细胞完全缺乏这种细胞骨架结构。在这种类型的细胞中，整个前期事件被阻断，第二分裂纺锤体的组装完全被阻止。
