Sugar fungus: mapping the genetic diversity of yeast

Genome Science and Technology PhD student Jackson Moore's (he/him) work is an interesting convergence of biotechnology, evolutionary biology, and functional genomics. While his work at Measday Lab focuses on the yeast Saccharomyces ceresiae in relation to wine fermentation, the lab also uses yeast as a model organism to study fundamental biology.

Local fermentors for local flavour

"In the wine world, wineries typically inoculate their grape juice with a commercially developed or domesticated strain," Jackson explains. "These strains have been domesticated because they enable rapid and robust fermentation, and have fermentation qualities that produce certain aromas or flavor compounds. However, the issue with using these commercial strains is that they're actually, at a genetic level, not very diverse. That translates into limited wine complexity at a phenotypic level."

These commercial strains originate from Europe. In contrast, Jackson's work focused on more local wild yeast which was isolated and sequenced in BC with the goal of creating a toolkit of yeast available to local wine producers. Partnering with wineries in the Okanagan Valley and in California, Jackson and team isolated yeast from those vineyards and identified a novel clade, Pacific West Coast Wine, which is more diverse than the mentioned commercial strains typically used in wine fermentation.

Where the intersection between biotechnology and fundamental biology comes to play is the fact that the clade is biotechnologically interesting due to its diversity, but it's also notable from a fundamental biology perspective because the clade is admixed, revealing the yeast's evolution.

Jackson explains, "This clade was generated by mating between two other populations of yeast. Historically, wine fermentation was developed in Europe, but as people moved and established wineries and vineyards in, for example, British Columbia, they brought those domesticated yeast with them. Those domestic yeast have become feral and spread out into the North American wine regions. As those domesticated yeast have spread, they've mated with wild yeast that have already been here for thousands of years. So the mating between wild yeast and domesticated yeast produced this Pacific West Coast Wine clade."

Better medicines from diverse testing

Another major component of Jackson's PhD included creating a library of diverse yeast strains screened across various pharmaceutical drugs and chemical stressors. The significance of this work is the evaluation of how drug response varies across genetic backgrounds.

As Jackson explains it, "This project focused on chemical genetics, including screening yeast across different pharmaceuticals, antifungals, or fungicides to understand how those chemical compounds interact with specific genes or specific genetic variants. For example, what are the mechanisms of resistance or sensitivity to some of these compounds? Using yeast as a model organism can inform not only how those compounds might interact with humans, but also in pathogenic fungi. As a model organism, most research has been focused on one specific strain, but the goal of this project was to expand our diversity and to incorporate the yeast that we isolated to develop a new library of yeast strains to be used for this chemical-genetic approach."

Considering the long history between people and yeast, such as various fermentation processes of bread, beer, wine, and more, Jackson's work is an important development in better understanding this relationship, as well as a curious exploration of natural variation and what it can teach us.

"You can learn a lot of things, from a fundamental perspective, by going out into nature and sequencing the genetics of the natural world—in this case, yeast," Jackson says. "The natural world has a lot to teach us still about evolution, genetics, and there are a lot of applications towards biotechnology and chemical genetics."

Life outside the lab

Outside of academics, Jackson enjoys being in the mountains and taking part in intramural sport teams at UBC. He is also passionate about music and partnered with another student in his program to start a band called Sugar Fungus based on Saccharomyces that they work with!