Changes in the centrin and microtubule cytoskeletons after metaphase arrest of the Chlamydomonas reinhardtii met1 mutant.
Changes in the centrin and microtubule cytoskeletons after metaphase arrest of the Chlamydomonas reinhardtii met1 mutant.
复制标题
莱茵衣藻 met1 突变体中期停滞后中心蛋白和微管细胞骨架的变化。
DOI：
10.1007/s00709-004-0069-z
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发表时间：
2004
期刊：
影响因子：
--
通讯作者：
Koutoulis,A
中科院分区：
文献类型：
--
作者：
Harper,JDI;Salisbury,JL;John,PCL;Koutoulis,A
温度敏感型条件衣藻在限制性温度(33 °C)条件下可在中期发生突变停滞，具有完整的纺锤体和较高的细胞分裂蛋白水平。在这项研究中，研究了MET1在33 °C停滞后微管和基于中心素的细胞骨架的变化。免疫荧光显微镜显示，在停滞初期，微管纺锤体和基于中心素的细胞骨架出现，与先前报道的野生型中期细胞相同；在细胞表面的基体区，新月形的纺锤体在每个纺锤体极处都有两个标记明亮的中心素焦点。在限制性温度下对Met1的观察表明，纺锤体可以从一个纺锤体极分离出来，染色体最终从纺锤体上分离出来。此外，在没有染色体分离的情况下，会发生纺锤体和细胞核伸长的假后期事件。电子显微镜证实，胞质分裂开始，细胞核保持新月形，但扩张，并检测到多个果核，表明叶绿体分裂也在继续。有趣的是，通常出现在暗生长植物黄体中的前板层样小体出现在核膜上。这些结果与莱茵衣藻分裂事件的协调和该突变株停滞细胞的活力丧失有关。
The temperature-sensitive conditionalmet1Chlamydomonas reinhardtiimutant arrests in metaphase at the restrictive temperature (33 °C) with an intact spindle and high cell division kinase levels. In this study,met1 was investigated with respect to changes in the microtubule and centrin-based cytoskeletons after arrest at 33 °C. Immunofluorescence microscopy revealed that, initially on arrest, the microtubule spindle and centrin-based cytoskeleton appeared as previously reported for wild-type metaphase cells; crescent-shaped spindles were seen with two brightly labelled centrin foci at each spindle pole in the basal body region at the cell surface. Observation ofmet1 held at the restrictive temperature reveals spindles can detach from one spindle pole and chromosomes eventually detach from the spindles. Moreover, a pseudo-anaphase event of spindle and nucleus elongation occurs in the absence of chromosome separation. Electron microscopy confirms that cytokinesis is initiated, the nuclei maintain a crescent shape but are distended and multiple pyrenoids are detected, suggesting chloroplast division also continues. Interestingly, prolamellar-like bodies usually present in etioplasts of dark-grown plants appear at the nuclear envelope. These results are discussed in relation to the coordination of division events inChlamydomonas reinhardtiiand the loss of viability in arrested cells of this mutant.