Department of Genetics and Microbiology, Faculty of Science, Charles University in Prague, Viničná 5, Prague 2, Czech Republic.
Fungal Genet Biol. 2010 Dec;47(12):1012-22. doi: 10.1016/j.fgb.2010.08.005. Epub 2010 Aug 20.
The lifestyle of wild and laboratory yeast strains significantly differs. In contrast to the smooth colonies of laboratory strains, wild Saccharomyces cerevisiae strains form biofilm-like, strikingly structured colonies possessing distinctive traits enabling them to better survive in hostile environments in the wild. Here, comparing three sets of strains forming differently structured colonies (fluffy, semi-fluffy and smooth), each derived from ancestors with distinct genetic backgrounds isolated from natural settings (BR-88, BR-99 and BR-103), we specified the factors essential for the formation of structured colonies, i.e. for the lifestyle most likely to be preferred in the wild. The ability to form an abundant extracellular matrix (ECM) is one of the features typical for structured colonies. ECM influences colony architecture and many other physiological properties, such as the capability to retain water in a 2-fold surplus to wet cell biomass. ECM composition, however, differs among distinct strains, depending on their particular genetic background. We further show that the expression of certain genes (AQY1, FLO11) is also strictly related to the particular colony morphology, being highest in the most structured colonies. Flo11p adhesin, important for cell-cell and cell-surface adhesion, is essential for the formation of fluffy colonies and thus significantly contributes to the phenotype variability of wild yeast strains. On the other hand, surprisingly, neither the cell shape nor budding pattern nor the ability to form pseudohyphae directly influences the formation of three-dimensional fluffy colony architecture.
野生酵母菌株和实验室酵母菌株的生活方式有很大的不同。与实验室菌株光滑的菌落相比，野生酿酒酵母菌株形成类似生物膜的、结构明显的菌落，具有独特的特征，使它们能够更好地在野外恶劣的环境中生存。在这里，我们比较了三套形成不同结构菌落（蓬松、半蓬松和光滑）的菌株，每一套菌株都源自具有不同遗传背景的祖先，这些菌株是从自然环境中分离出来的（BR-88、BR-99 和 BR-103），我们确定了形成结构化菌落的必要因素，即最有可能在野外选择的生活方式。形成丰富的细胞外基质（ECM）的能力是结构化菌落的特征之一。ECM 影响菌落结构和许多其他生理特性，例如保留比湿细胞生物量多出两倍的水的能力。然而，ECM 组成因菌株而异，取决于其特定的遗传背景。我们进一步表明，某些基因（AQY1、FLO11）的表达也与特定的菌落形态严格相关，在最结构化的菌落中表达最高。Flo11p 黏附素对细胞间和细胞表面的黏附很重要，是形成蓬松菌落所必需的，因此对野生酵母菌株表型的可变性有重要贡献。另一方面，令人惊讶的是，细胞形状、出芽模式或形成假菌丝的能力都不会直接影响三维蓬松菌落结构的形成。
