Eukaryotic Cell doi:10.1128/EC.00310-06
Copyright (c) 2007, American Society for Microbiology and/or the Listed Authors/Institutions. All Rights Reserved.
Mat formation in Saccharomyces cerevisiae requires nutrient and pH gradients
Todd B. Reynolds,
An Jansen,
Xin Peng,
and
Gerald R. Fink
Department of Microbiology, University of Tennessee, Knoxville, TN 37996; Whitehead Institute for Biomedical Research, 9 Cambridge Center, Cambridge, MA 02142
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Abstract |
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The ability of Saccharomyces cerevisiae to form morphologically complex colony-like structures called mats requires expression of the cell surface glycoprotein Flo11p and growth on a semi-solid surface. As it grows, the mat forms two visually distinct populations called the rim (edge of the mat) and the hub (interior of the mat), which can be physically separated from one another based on their agar-adherence properties. Here we show that growth of the mat on a semi-solid agar surface creates concentric glucose and pH gradients in the medium that are required for the differentiation of the hub and rim. Disruption of pathways that respond to changing levels of glucose block mat formation by decreasing FLO11 expression. However, in wild-type cells Flo11p is expressed in both portions of the structure. The difference in adherence between the rim and hub appears to be a consequence of the reduced adherence of Flo11p at the elevated pH of the rim.
