title: Mat formation in Saccharomyces cerevisiae requires nutrient and pH gradients.
abstract: 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 semisolid surface. As the mat grows, it 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 semisolid agar surface creates concentric glucose and pH gradients in the medium that are required for the differentiation of the hub and rim. Disruption of the 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.
authors.affiliation: Department of Microbiology, University of Tennessee, F321 Walters Life Sciences Bldg., Knoxville, TN 37996, USA. treynol6@utk.edu
authors.forename: Todd B
authors.initials: TB
authors.lastname: Reynolds
authors.forename: An
authors.initials: A
authors.lastname: Jansen
authors.forename: Xin
authors.initials: X
authors.lastname: Peng
authors.forename: Gerald R
authors.initials: GR
authors.lastname: Fink
mesh_terms: D015152:Blotting, Northern; D002448:Cell Adhesion; D005455:Fluorescent Antibody Technique; D015966:Gene Expression Regulation, Fungal; D005947:Glucose / Q000378:metabolism*; D008025:Ligases / Q000235:genetics / Q000378:metabolism; D008562:Membrane Glycoproteins; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D018892:Proton-Motive Force; D012331:RNA, Fungal / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012441:Saccharomyces cerevisiae / Q000254:growth & development* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*
chemical_list: C110690:FLO11 protein, S cerevisiae; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D012331:RNA, Fungal; D029701:Saccharomyces cerevisiae Proteins; D008025:Ligases; C452202:HUB1 protein, S cerevisiae; D005947:Glucose