We studied population development of wild Saccharomyces cerevisiae strains. The strains exhibit considerable phenotypic variability comprising differently structured fluffy, semi-fluffy and smooth colonies differing in gene expression and extracellular matrix production.
Despite heterogeneous origin of the strains, we discovered interesting common features. The colony morphology is generally influenced by carbon source and by the presence of extracellular matrix.
Expression level of some genes influencing cell morphogenesis and cell surface properties (e.g. FLO11 and AQY1) correlates with colony morphology, being strongest in fluffy colonies.
Using newly constructed wild strains containing FLO11 gene fused with GFP, we explored the role of Flo11p adhesin in colony development. Our results show that Flo11p plays an important role not only in cell morphogenesis but also in early steps of aerial fluffy colony development and is essential for proper formation of three-dimensional colony architecture.