【摘要】 应用间接免疫荧光标记技术和激光共聚焦扫描显微镜成像技术观察了烟草小孢子母细胞减数分裂过程中微管的分布变化。在减数分裂前期,小孢子母细胞中的微管较短,随机分散在细胞质中。在减数分裂中期,细胞质中微管形成纺锤体,控制染色体的分布。进入减数分裂I后期,部分纺锤体微管将两组染色体拉向两级。在减数分裂Ⅱ中期,细胞中的微管又形成两个纺锤体。在减数分裂Ⅱ后期,纺锤体微管解聚为微管蛋白分散在细胞质中。胞质分裂发生在四个细胞核形成之后,通过细胞核之间的质膜向内缢缩分隔四个细胞核,产生四个小孢子。更多还原

【Abstract】 The organization of microtubule cytoskeleton during tobacco microsporogenesis was observed. At the prophase of meiosis I of microspore mother cell(MMC),the microtubules in the cell are short and dispersive in cytoplasm.At the metaphase of meiosis I,the microtubules in the cell set up a spindle which makes chromosomes move at equatorial plate.When MMCs enter the anaphase of meiosisⅠ,the spindle microtubules break.At the metaphase of meiosisⅡ,the microtubules form two spindles in the same cytoplasm.In the telophase of meiosisⅡ, spindle microtubules depolymerize and change from short segment to tubulin.Then the MMC begins to cytokinesis by cytoplasmic constriction to form contractile furrows,which separate four nuclei into four microspores.There was not evidence to show that microtubules participate in the cytokinesis directly.更多还原