Jackson SL, Hardham AR
Research School of Biological Sciences, The Australian National University, Canberra, ACT, 2601, Australia.
Fungal Genet Biol. 1998 Jun;24(1-2):24-33. doi: 10.1006/fgbi.1998.1071.
The organization of filamentous actin (F-actin) in living cells of the oomycete Phytophthora cinnamomi was determined during zoosporogenesis and zoospore encystment by microinjecting sporangia with fluorescently labeled phalloidin and observing resultant fluorescence by confocal microscopy. In multinucleate sporangia prior to the induction of cleavage, phalloidin labeling took the form of plaques which occurred mainly in the periphery of the sporangia. After induction of cleavage, phalloidin labeling showed that the plaques disappeared and that F-actin began to accumulate along the developing cleavage planes and around nuclei and water expulsion vacuoles. F-actin labeling was also observed near the plasma membrane in zoospores and young cysts but reverted to the plaque form in older cysts. Localization of F-actin close to the developing cleavage planes is consistent with the idea that actin microfilaments function in the positioning and expansion of the cleavage membranes. Observations of plaques of actin in living sporangia provide evidence that plaques are not aldehyde-induced fixation artifacts. Copyright 1998 Academic Press.
通过向孢子囊显微注射荧光标记的鬼笔环肽并利用共聚焦显微镜观察产生的荧光，确定了樟疫霉卵菌活细胞中丝状肌动蛋白（F-肌动蛋白）在游动孢子形成和游动孢子包囊化过程中的组织情况。在诱导分裂之前的多核孢子囊中，鬼笔环肽标记呈斑块状，主要出现在孢子囊的周边。诱导分裂后，鬼笔环肽标记显示斑块消失，F-肌动蛋白开始沿着发育中的分裂平面以及细胞核和排水液泡周围积累。在游动孢子和幼龄包囊中，也在质膜附近观察到F-肌动蛋白标记，但在老龄包囊中又恢复为斑块状。F-肌动蛋白靠近发育中的分裂平面的定位与肌动蛋白微丝在分裂膜的定位和扩展中起作用的观点一致。在活孢子囊中观察到的肌动蛋白斑块提供了证据，表明这些斑块不是醛诱导的固定假象。版权所有1998年学术出版社。
