Actin has multiple roles in the formation and architecture of zoospores of the oomycetes, Saprolegnia ferax and Achlya bisexualis
Actin has multiple roles in the formation and architecture of zoospores of the oomycetes, Saprolegnia ferax and Achlya bisexualis
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肌动蛋白在卵菌、水霉和双性蠹的游动孢子的形成和结构中具有多种作用
DOI：
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发表时间：
1992
期刊：
影响因子：
--
通讯作者：
R. Harold
中科院分区：
文献类型：
--
作者：
I. Heath;R. Harold
罗丹明-鬼笔藻素标记的肌动蛋白在卵菌群游动孢子生命周期中的变化模式非常相似。通过将这些变化与先前描述的超微结构和功能变化进行比较，我们表明肌动蛋白在许多以前未被认识的过程中发挥作用。最引人注目的是，细胞动力系统的定向囊泡扩张涉及新形成的肌动蛋白，它勾勒出正在发育的游动孢子。这种肌动蛋白被细胞松弛素破坏会导致异常的卵裂，表现为大而不规则的囊泡的形成。在胞质分裂之前，合成了两种新类型的细胞器，其中一种被称为K小体，聚集在细胞核周围。这些细胞器在发育和聚集过程中肌动蛋白含量丰富，与其定位的肌动蛋白功能一致。在游动孢子中，肌动蛋白集中在排水液泡周围，表明它们是收缩的，并渗透到细胞质中，可能具有骨骼作用。首次证实了肌动蛋白与次生游动孢子中的微管状根相关。包被后，染色的肌动蛋白以与新合成的细胞壁相关的周边斑块的形式急剧增加。当包囊萌发时，在芽管顶端形成纤维状肌动蛋白帽，这与之前在菌丝顶端所描述的相似，但只有在细胞壁软化后才能允许胚管伸出。这一序列与先前对菌丝所讨论的肌动蛋白帽调节膨大驱动的尖端扩张是一致的。除了破坏裂解相关的肌动蛋白外，细胞松弛素还显示出发育阶段、剂量和药物(CE≥CD≥CB)对与动物孢子形成相关的肌动蛋白的特定影响，这表明，与先前的建议相反，罗丹明-菲洛定染色是肌动蛋白响应细胞松弛素行为的有用指标。这些反应包括对相邻肌动蛋白阵列的不同影响，其中一些在药物持续存在时是短暂的，表明药物适应的机制。
Very similar changing patterns of actin are described with rhodamine-phalloidin labelling during the zoosporic life cycle of the oomycetes, Saprolegnia ferax and Achlya bisexualis. By comparing the changes with previously described ultrastructural and functional changes, we show that actin functions in numerous previously unrecognized processes. Most spectacularly, the directed vesicle expansions of the cytokinetic system involve newly formed actin which outlines the developing zoospores. Disruption of this actin with cytochalasins leads to abnormal cleavage as witnessed by the formation of enlarged and irregular cysts. Prior to cytokinesis, two new types of organelle are synthesized and one, known as K bodies, clusters around the nuclei. These organdies are actin-rich during development and clustering, consistent with actin functioning in their positioning. In the zoospores, actin is concentrated around the water expulsion vacuoles, indicating that they are contractile, and permeates the cytoplasm, probably with a skeletal role. This concept is supported by the first demonstration of actin specifically associated with a microtubular root in the secondary zoospore. Upon encystment there is a dramatic increase in stained actin in the form of peripheral plaques associated with the newly synthesized cell wall. When the cysts germinate, a fibrillar actin cap, comparable to that previously described in hyphal tips, forms in the germ tube apex, but only after cell wall softening to permit germ tube protrusion. This sequence is consistent with the actin cap modulating turgor-driven expansion of the tip as previously discussed for hyphae. In addition to disrupting cleavage-associated actin, cytochalasins show developmental stage, dose and drug (CE≥CD≥CB) specific effects on zoosporulation-related actin, which indicates that, contrary to previous suggestions, rhodamine-phalloidin staining is a useful indicator of actin behaviour in response to cytochalasins. These responses include differential effects on adjoining actin arrays, some of which are transient in the continued presence of the drugs, indicating a mechanism of drug adaptation.
趋化性和分支是双性蠹对氨基酸的替代反应。
DOI：
10.1099/00221287-135-9-2519
发表时间：
1989
期刊：
Journal of general microbiology
影响因子：
--
作者：
Schreurs,WJ;Harold,RL;Harold,FM
通讯作者：
Harold,FM
影响因子：
--
作者：
Xiaojing Tang;S. Lancelle;P. K. Hepler
通讯作者：
Xiaojing Tang;S. Lancelle;P. K. Hepler