Analysis of the different colony morphotypes of the feral strains of Saccharomyces cerevisiae.
Martin Kuthan, Zdena Palkova
Dept. Genetics and Microbiol., Charles University, Vinicna 5, Prague, 12844, Czech Republic
Many wild strains of Saccharomyces cerevisiae create structured colonies with peculiar colony morphologies strikingly contrasting with the smooth colony morphology of the laboratory strains. Previously, we characterised the feral strain BR-97 which exhibits brain-like fluffy colony morphology. This strain effectively switches to smooth colony morphology during long time cultivation under laboratory conditions. This switch is accompanied by specific changes in gene expression and by the loss of extracellular matrix (Kuthan et al., Mol. Microbiol. 47(3):745-54, 2003). In this work we analysed colonies of three other feral strains of S. cerevisiae creating colonies of several different morphologies. We investigated the structure and ultrastructure of the different colony morphologies using light microscopy and environmental scanning microscopy. We followed the amount of the extracellular matrix material in the colonies. Additionally, we examined invasiveness and karyotypes of the strains. Our results show the common features and the differences among unrelated feral strains as well as among distinct colony morphotypes of the particular strains. This work was supported by grants GACR 204/03/H066, IAA500200506 and The DuPont Young Faculty to M.K.