Quantitative analysis of changes in spatial distribution and plus-end geometry of microtubules involved in plant-cell cytokinesis
Quantitative analysis of changes in spatial distribution and plus-end geometry of microtubules involved in plant-cell cytokinesis
复制标题
DOI：
10.1242/jcs.02512
复制
发表时间：
2005-09-01
影响因子：
4
通讯作者：
Staehelin, LA
中科院分区：
文献类型：
--
作者：
Austin, JR;Seguí-Simarro, JM;Staehelin, LA
高等植物的细胞板形成在排除核糖体的细胞板组装基质内。成膜体微管通过形成支架将高尔基体衍生的囊泡引导至形成中的细胞板来促进细胞板的形成。在这里，我们分析了细胞板组装矩阵上成膜体微管加端几何形状的影响，通过电子断层扫描低温固定的拟南芥分生组织细胞。观察到五种不同的微管加端几何形状-钝的、延伸的、有角的、喇叭形的和混合延伸/有角的。我们已经量化和映射这些类型的加端形态在细胞板形成的不同阶段，并分析了微管加端形态的细胞板组装矩阵协会的影响。我们的研究结果表明，体细胞型成膜体微管不交错在细胞板中线。细胞-板组装基质显示出稳定微管加末端，如以下事实所证明的：在这些不在这种基质中终止的微管中，40-80%是喇叭形的（收缩），而在这种基质中终止的那些微管中，50-70%是钝的（亚稳的）。此外，细胞板组装基质内的三分之一的钝端微管在距离细胞板近似30 nm处终止。
The cell plate of higher plants is formed within a ribosome-excluding cell plate assembly matrix. Phragmoplast microtubules facilitate cell-plate formation by forming a scaffold that directs Golgi-derived vesicles to the forming cell plate. Here, we analyse the effects of the cell-plate assembly matrix on phragmoplast microtubule plus-end geometry by electron tomography of cryogenically fixed Arabidopsis meristem cells. Five distinct microtubules plus-end geometries are seen - blunt, extended, horned, flared and hybrid extended/horned. We have quantified and mapped these types of plus-end morphology during the different stages of cell-plate formation and analysed the effects of cell-plate assembly matrix association on microtubule plus-end morphologies. Our results show that somatic-type phragmoplast microtubules do not interdigitate at the cell plate mid-line. The cell-plate assembly matrix is shown to stabilize microtubule plus ends, as evidenced by the fact that of these microtubules that do not terminate in such a matrix, 40-80% are horn-shaped (shrinking), whereas of those that end in such a matrix, 50-70% are blunt (metastable). Also, a third of the blunt-ended microtubules within the cell-plate assembly matrix end at a distance of similar to 30 nm from the cell plate.