Presentation Title

Saccharomyces cerevisiae Evolve Resistance to an Antifungal Compound Through Mutations in PDR1, PDR3, Chromosome VIII Duplication, and Mitochondrial Genome Loss

Faculty Mentor

Ryan Skophammer

Start Date

17-11-2018 8:30 AM

End Date

17-11-2018 10:30 AM

Location

CREVELING 90

Session

POSTER 1

Type of Presentation

Poster

Subject Area

biological_agricultural_sciences

Abstract

Although many experimental evolution studies have been done with antibiotics, far fewer experiments have explored the evolution of resistance to antifungal treatments. In this yearlong project, our AP Biology class used experimental evolution to engineer yeast strains to resist the over-the-counter antifungal treatment FungiCure. After receiving sequencing results for our evolved Saccharomyces cerevisiae strains from the University of Washington Dunham Lab and identifying causal mutations in the resistant groups, we conducted a literature investigation to examine possible mechanisms of resistance. The sequencing revealed missense mutations in the PDR1 and PDR3 genes as well as mitochondrial loss and chromosome VIII duplications. Mutations in PDR1 and PDR3 cause the upregulation of genes involved in azole resistance.

This year-long experiment on the development of antifungal resistance in Saccharomyces cerevisiae served primarily to guide and enhance our learning throughout the AP Biology course. These investigations helped to broaden our understanding of key biological processes, including evolution, gene expression, gene regulation, and cellular communication. Implementing a series of connected labs concerning yeast in place of conventional, unrelated experiments created a more integrated AP Biology curriculum, allowing us to learn the basics of experimental design, hypothesis testing, and data analysis throughout the year while we conducted an original investigation.

Summary of research results to be presented

We found nine mutations in the PDR1 gene, six of which were in the regulatory domain 200-900. It has been found this domain can be stimulated by azoles binding to PDR1, making the gene active in upregulating genes involved in azole resistance. We found three strains of yeast with a mutation in the PDR3 gene. The PDR3 gene makes the zinc finger protein PDR3 which regulates ABC transporters such as PDR5 and SNQ2. A mutation in this gene might cause increased upregulation of genes involved in azole resistance. Three strains of yeast had a duplication in chromosome VIII, which includes the ERG11 gene. The ERG11 gene helps form ergosterol in fungi, and overexpression of ERG11 leads to antifungal drug resistance through affecting the permeability of cell membranes. Ten of the fourteen yeast strains lost their mitochondrial genome. The loss of mitochondrial genome leads to hypoxic conditions and anaerobic respiration, which could increase activity in a gene that regulates azole resistance, as the loss of mitochondria may upregulate PDR1 gene activity.

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Nov 17th, 8:30 AM Nov 17th, 10:30 AM

Saccharomyces cerevisiae Evolve Resistance to an Antifungal Compound Through Mutations in PDR1, PDR3, Chromosome VIII Duplication, and Mitochondrial Genome Loss

CREVELING 90

Although many experimental evolution studies have been done with antibiotics, far fewer experiments have explored the evolution of resistance to antifungal treatments. In this yearlong project, our AP Biology class used experimental evolution to engineer yeast strains to resist the over-the-counter antifungal treatment FungiCure. After receiving sequencing results for our evolved Saccharomyces cerevisiae strains from the University of Washington Dunham Lab and identifying causal mutations in the resistant groups, we conducted a literature investigation to examine possible mechanisms of resistance. The sequencing revealed missense mutations in the PDR1 and PDR3 genes as well as mitochondrial loss and chromosome VIII duplications. Mutations in PDR1 and PDR3 cause the upregulation of genes involved in azole resistance.

This year-long experiment on the development of antifungal resistance in Saccharomyces cerevisiae served primarily to guide and enhance our learning throughout the AP Biology course. These investigations helped to broaden our understanding of key biological processes, including evolution, gene expression, gene regulation, and cellular communication. Implementing a series of connected labs concerning yeast in place of conventional, unrelated experiments created a more integrated AP Biology curriculum, allowing us to learn the basics of experimental design, hypothesis testing, and data analysis throughout the year while we conducted an original investigation.