The Role of the Allantoin Pathway in Plastic Adherence in Saccharomyces cerevisiae

The allantoin pathway is crucial for nitrogen degradation in Saccharomyces yeast. It has been discovered to be a fast-evolving pathway and has many applications for natural yeast strains. Allantoin is key for growth of yeast on different media, specifically natural substrate (Treu et al, 2014).  Allantoin utilization is encoded by a cluster (similar to an operon) of genes called the DAL genes. Previous research in the lab has indicated that the DAL genes are involved in plastic adherence in S. cerevisiae. Plastic adherence is a social phenotype in yeast, suggesting that it is evolutionary advantageous for yeast cells to form mats, floccs, and biofilms in order to fight against harsh environments and competitors (Deschaine et al, 2017). This connection implies that the the allantoin pathway, a typically biochemical degradation pathway, also has a role in social phenotypes. Globally available genomic data will be used to identify variation in the DAL cluster and its regulators. Gene-knockout analysis will be employed to determine the specific connection between allantoin, the DAL genes, and plastic adherence.

Yeast cells that exhibit plastic adherence as well as other social phenotypes can form biofilms on plastic materials, including catheters, as well as other medical equipment. This is especially harmful to immuno-compromised persons as well as the maintenance of sterile medical environments. As S. cerevisiae forms plastic-adhering biofilms, the possibility for evolving pathogenicity and virulence poses a greater threat to medical treatment. Identifying the genetic architecture of this gene as well as its patterns of selection is crucial to understanding how yeast cells form aggregates on different types of media, specifically those with plastic components. The connection between the allantoin pathway and plastic adherence may provide further information on how these yeast cells form such biofilms and become virulent.