Microtubule and F-actin dynamics at the division site in living Tradescantia stamen hair cells
Microtubule and F-actin dynamics at the division site in living Tradescantia stamen hair cells
复制标题
DOI：
--
复制
发表时间：
1992-12
影响因子：
4
通讯作者：
A. Cleary;B. Gunning;G. Wasteneys;P. K. Hepler
中科院分区：
文献类型：
--
作者：
A. Cleary;B. Gunning;G. Wasteneys;P. K. Hepler
在显微注射罗丹明-鬼臼蛋白或羧基荧光素标记的脑微管蛋白后，我们用激光共聚焦扫描显微镜在活的紫露草雄蕊毛细胞中观察到了F-肌动蛋白和微管。我们监测了细胞骨架的这些成分，因为细胞在前期准备分裂，并通过有丝分裂向胞质分裂发展。间期皮质细胞骨架的重组导致在细胞皮质中共存的F-肌动蛋白和微管的前期条带，集中在未来细胞板与亲本细胞壁融合的位置。微管的前期带是由在前期聚合和结合微管蛋白的微管形成的。肌动蛋白的前相前带可以通过重组已存在的细丝或通过从头聚合形成。这两个细胞骨架组件在核包膜破裂前大约五分钟从未来的分区地点消失。皮质微管在整个有丝分裂和胞质分裂过程中都检测不到，而皮质F-肌动蛋白仍然丰富，尽管它明显被排除在分裂部位之外。含有F-肌动蛋白和微管的成膜体，通过一个没有可检测到的微管或F-肌动蛋白的区域向皮质肌动蛋白隔离区扩张。成膜细胞停留在皮质中缺乏F-肌动蛋白的预定义区域。提示皮质F-肌动蛋白可以作为一个“负性”模板，正确定位成膜体和细胞板。这是在活的植物细胞中F-肌动蛋白在分裂部位的动力学的第一个活体文献。摘要
We have visualised F-actin and microtubules in living Tradescantia virginiana stamen hair cells by confocal laser scanning microscopy after microinjecting rhodamine-phalloidin or carboxyfluorescein-labelled brain tubulin. We monitored these components of the cytoskeleton as the cells prepared for division at preprophase and progressed through mitosis to cytokinesis. Reorganisation of the interphase cortical cytoskeleton results in preprophase bands of both F-actin and microtubules that coexist in the cell cortex, centred on the site at which the future cell plate will fuse with the parent cell wall. The preprophase band of microtubules is formed from microtubules that polymerise and incorporate tubulin during prophase. The preprophase band of actin may form either by reorganisation of pre-existing filaments or by de novo polymerisation. Both cytoskeletal components disappear from the future division site approximately five minutes prior to the breakdown of the nuclear envelope. Cortical microtubules are undetectable throughout mitosis and cytokinesis, whereas cortical F-actin remains abundant, although it is notably excluded from the division site. The phragmoplast, containing both F-actin and microtubules, expands towards the cortical actin exclusion-zone through a region that has no detectable microtubules or F-actin. The phragmoplast comes to rest in the predefined region of the cortex that is devoid of F-actin. It is proposed that cortical F-actin may act as a “negative” template which could position the phragmoplast and cell plate correctly. This is the first in vivo documentation of F-actin dynamics at the division site in living plant cells. Summary