Kuthan Martin, Devaux Frédéric, Janderová Blanka, Slaninová Iva, Jacq Claude, Palková Zdena
Department of Genetics and Microbiology, Charles University, Vinicná 5, 12844 Prague 2, Czech Republic.
Mol Microbiol. 2003 Feb;47(3):745-54. doi: 10.1046/j.1365-2958.2003.03332.x.
Although colonies from Saccharomyces cerevisiae laboratory strains are smooth, those isolated from nature exhibit a structured fluffy pattern. Environmental scanning electron microscopy shows that the cells within wild fluffy colonies are connected by extracellular matrix (ECM) material. This material contains a protein of about 200 kDa unrelated to the flocculins, proteins involved in cell-cell adhesion in liquid media. The matrix material binds to concanavalin A. Within a few passages on rich agar medium, the wild strains switch from the fluffy to the smooth colony morphology. This domestication is accompanied by loss of the ECM and by extensive changes in gene expression as detected by DNA microarrays. The expression of about 320 genes was changed in smooth colonies. The major changes comprise carbohydrate metabolism, cell wall, water channels, Ty-transposons and subtelomeric genes, iron homeostasis, vitamin metabolism and cell cycle and polarity. The growth in fluffy colonies may represent a metabolic strategy for survival of yeast under unfavourable conditions that is switched off under felicitous laboratory conditions.
虽然酿酒酵母实验室菌株形成的菌落是光滑的，但从自然界分离出的菌株表现出一种有结构的蓬松形态。环境扫描电子显微镜显示，野生蓬松菌落中的细胞通过细胞外基质（ECM）物质相连。这种物质含有一种约200 kDa的蛋白质，与絮凝蛋白无关，絮凝蛋白是参与液体培养基中细胞间粘附的蛋白质。基质物质与伴刀豆球蛋白A结合。在富含琼脂的培养基上传代几次后，野生菌株从蓬松菌落形态转变为光滑菌落形态。这种驯化伴随着ECM的丧失以及DNA微阵列检测到的基因表达的广泛变化。在光滑菌落中约320个基因的表达发生了变化。主要变化包括碳水化合物代谢、细胞壁、水通道、Ty转座子和亚端粒基因、铁稳态、维生素代谢以及细胞周期和极性。在蓬松菌落中的生长可能代表了酵母在不利条件下生存的一种代谢策略，而在适宜的实验室条件下这种策略会关闭。
