甘蔗茎尖细胞有丝分裂过程中微管骨架的变化

目的]研究单子叶植物茎尖有丝分裂细胞的微管动态变化情况。方法]采用冰冻切片法结合间接免疫荧光技术及DAPI染色,利用荧光显微镜观察甘蔗茎尖细胞有丝分裂时微管列阵的排列、转换及与染色体运动的关系。结果]当周质微管形成时,细胞核保持完整;有丝分裂前期,周质微管转变为早前期微管带;当纺锤体微管形成时,细胞核膜破裂,染色体排列在细胞板位置;之后纺锤体微管向成膜体微管转换,纺锤体微管逐渐缩短而细胞板两侧微管逐渐增加,在这个过程中姊妹染色体被微管从细胞板处分离并牵引至两极,从而形成成膜体微管;之后两个子细胞的细胞核形成,并最终分裂,细胞数量增加。结论]从细胞微管各时期的排列就可以判断出细胞分裂方向,了解其生长情况,为甘蔗增粗机理的研究提供例证。

The Change of Microtubule Cytoskeleton in The Stem-Tip Cellsof Sugarcane during Mitosis

Objective]The microtubules dynamic change of stem tip of monocotyledon during mitosis was studied in the experiment.Method]In order to understand the microtubule change of monocotyls stem-tip and the arrangement,transformation of microtubule array and its relation with chromosome movement during mitosis were studied through freezing microtome method,indirect immunofluorescence,DAPI staining and fluorescence microscopy.Result]The nucleolus was intact when the cortical microtubules formed;cortical microbubules were changed into phramoplast microtubule bands at mitosis prophase.When phramoplast microtubule came into being,nuclear membrane was ruptured and chromosome was arranged at the position of cell plate;subsequently,phramoplast microtubules were changed into phragmoplast microtubules,phramoplast microtubules were shortening and microtubules on two sides of cell plate were increased gradually.During this course,sister chromatid was separated in the end with the increase of cells number.Conclusion]Therefore,cell division orientation could be judged from the arrangement of cell microtubules in different periods in order to understand its growth status.