Understanding the evolution of regulatory networks is critical to understanding how cells work and adapt to changing environments. Stephany and her mentors sought to determine the differential expression patterns of metabolism genes in two species of yeast, K. waltii and K. polysporus, grown in different environmental conditions.
Stephany used microarrays to analyze differences in gene expression between samples of these two yeast species grown in rich media with glucose and then shifted into minimal media with glycerol. She compared gene expression between K. waltii cultures grown under various conditions, and found clusters of genes that were repressed or induced in low glucose environments. She then compared gene expression between K. waltii and K. polysporus, and discovered some clusters of genes that showed convergent expression in the two species, and other clusters that showed divergent expression. Stephany’s data will be combined with those from 15 species in multiple growth conditions, to help discern the evolution of regulatory networks in yeast.