RELATIONSHIP OF ACTIN ORGANIZATION TO GROWTH IN THE 2 FORMS OF THE DIMORPHIC YEAST CANDIDA-TROPICALIS
RELATIONSHIP OF ACTIN ORGANIZATION TO GROWTH IN THE 2 FORMS OF THE DIMORPHIC YEAST CANDIDA-TROPICALIS
复制标题
DOI：
10.1007/bf01403383
复制
发表时间：
1992-01-01
期刊：
影响因子：
2.9
通讯作者：
OSUMI, M
中科院分区：
文献类型：
--
作者：
KOBORI, H;SATO, M;OSUMI, M
热带假丝酵母是一种二型酵母，根据培养基中使用的碳源，它既能作为芽殖酵母生长，也能作为丝状菌丝生长。通过使用常规荧光显微镜以及激光扫描共聚焦荧光显微镜，通过罗丹明缀合的鬼笔环肽可视化酵母形式（Y-形式）和菌丝形式（H-形式）生长期间的F-肌动蛋白的组织。在没有芽或不生长的菌丝的单细胞中，肌动蛋白点均匀地分布在整个细胞质中。在芽或菌丝生长之前，肌动蛋白点集中在一个位置。在芽的生长过程中，肌动蛋白点仅位于芽中。它们充满了小芽，然后充满了中等大小芽的顶端三分之二的细胞质。在大芽的生长过程中，充满细胞质顶半部分的肌动蛋白点逐渐向芽尖移动。在隔膜形成过程中，肌动蛋白点在芽与母细胞连接处呈两行排列。菌丝生长过程中，肌动蛋白点主要集中在菌丝顶端。只有在新隔即将形成的部位才能观察到一条成簇的斑点线或一条肌动蛋白带。这两类细胞中肌动蛋白的空间和时间组织被证明是密切相关的新的细胞壁材料的生长和局部沉积通过监测与Calcofluor染色的生长模式。用细胞松弛素A（CA）处理两种形式的细胞证实了肌动蛋白和新细胞壁沉积之间的密切关系。CA处理揭示了轻度染色的未定位的肌动蛋白，这与异常的细胞壁沉积以及形态学变化有关。这些结果表明，肌动蛋白是必要的适当的生长和适当的沉积细胞壁材料，也为维持形态的两种形式的细胞。
Candida tropically is a dimorphic yeast capable of growing both as a budding yeast and as filamentous hyphae depending upon the source of the carbon used in the culture medium. The organization of F-actin during growth of the yeast form (Y-form) and the hyphal form (H-form) was visualized by rhodamine-conjugated phalloidin by using a conventional fluorescence microscope as well as a laser scanning confocal fluorescence microscope. In single cells without a bud or non-growing hyphae, actin dots were evenly distributed throughout the cytoplasm. Before the growth of the bud or hypha, the actin dots were concentrated at one site. During bud growth, actin dots were located solely in the bud. They filled the small bud and then filled the apical two-thirds of the cytoplasm of the middle-sized bud. During growth of the large bud, actin dots which had filled the apical half of the cytoplasm gradually moved to the tip of the bud. In the formation of the septum, actin dots were arranged in two lines at the conjunction of the bud and the mother cell. During hyphal growth, the majority of actin dots were concentrated at the hyphal apex. A line of clustered spots or a band of actin was observed only at the site where the formation of a new septum was imminent. This spatial and temporal organization of actin in both categories of cells was demonstrated to be closely related to the growth and local deposition of new cell wall material by monitoring the mode of growth with Calcofluor staining. Treatment of both forms of cells with cytochalasin A (CA) confirmed the close relationship between actin and new cell wall deposition. CA treatment revealed lightly stained unlocalized actin which was associated with abnormal cell wall deposition as well as changes in morphology. These results suggest that actin is required for proper growth and proper deposition of cell wall material and also for maintaining the morphology of both forms of cells.