Caffeine-tolerant mutations selected through an at-home yeast experimental evolution teaching lab

Area of Science:

• Evolutionary Biology
• Microbiology
• Genetics

Background:

• yEvo is a high school curriculum utilizing evolution experiments with *Saccharomyces cerevisiae* (yeast).
• Adapting hands-on science curricula for remote learning presents unique challenges.
• Understanding yeast adaptation to environmental stressors like caffeine is crucial.

Purpose of the Study:

• To develop and validate a remote-accessible protocol for studying yeast evolution.
• To investigate the genetic basis of caffeine tolerance in *S. cerevisiae* using an at-home experimental setup.
• To demonstrate the utility of accessible, at-home evolution experiments for generating novel biological insights.

Main Methods:

• Developed a novel protocol for evolving non-engineered *S. cerevisiae* in the presence of caffeine for remote instruction.
• Characterized evolved yeast strains for caffeine tolerance and colony morphology.
• Performed genetic analyses, including whole-genome sequencing, to identify mutations and variations in evolved strains.

Main Results:

• Evolved yeast strains exhibited significantly increased tolerance to caffeine.
• Distinct colony morphologies were observed in evolved strains compared to ancestral strains.
• Genetic analysis revealed copy number variations, transposon insertions, and mutations in genes related to caffeine metabolism, TOR signaling, and other novel pathways.

Conclusions:

• The accessible, at-home yeast evolution protocol is effective for remote science education.
• The protocol enables the discovery of novel genetic mechanisms underlying adaptation to caffeine.
• This study highlights the potential of citizen science and remote experimentation in advancing biological research.