Regulation of Sliding Motility During Biofilm Formation in Fungi

University Of Tennessee Knoxville, Knoxville TN

Investigators

Abstract

Intellectual Merit This project will elucidate how proteins and polymers that compose the yeast cell wall control the formation of biofilms, which are multicellular, surface-adherent microbial communities. Yeast are often thought of as single-celled fungi in which individual cells act independently of one another. However, many yeast species can generate biofilms. This project is a study of how the yeast, Saccharomyces cerevisiae, uses sliding motility as a mechanism for biofilm formation. Sliding motility is a form of passive translocation in which microbes spread over a wet surface as they grow due to altered surface properties. The yeast biofilm consists of a collection of adherent cells that are surrounded by a loose vanguard of cells at the outer edge. The edge cells continue to divide, spread, and slide over the surface due to their altered cell wall properties. The goal of this project is to identify genes required for sliding, and determine how they foster sliding motility. The project seeks to fit two established cellular pathways into biofilm regulation, the cell wall integrity pathway and the multivesicular body trafficking pathway, which controls trafficking, recycling, and degradation of primarily ubiquitinated cell-surface proteins. The project also seeks to identify new genes, particularly cell wall genes, which control biofilm sliding behaviors. The primary tools used are genetic and biological approaches, with some reliance on genomic data. The study is important because it will promote understanding of how fungi form biofilms which are associated with fungal distribution and growth that impacts industry and ecosystems. The project will also help to explain a mechanism of motility that is more dependent on growth than on the activity of surface appendages. Broader Impacts The project will support outreach activities to promote instruction at the secondary school level through a collaboration with a local high school for using the yeast model as a dynamic teaching tool. The teaching project includes training high school teachers during a summer internship and then using undergraduate students, who are interested in science education as a career, in conjunction with graduate students to assist teachers in the classroom while teaching the modules. The project also will support the integration of research in education at the home institution through a plan to incorporate classical yeast genetic analysis into an existing undergraduate Microbial Genetics course. In addition the project will support a plan to incorporate whole genome deletion library screening into the class in the Fall of 2009 based on original research.