Differential paralog divergence modulates genome evolution across yeast species
A) Schematic of strains used in the competition assay to measure the relative fitness of the null alleles in the S. cerevisiae and S. uvarum backgrounds. B) The relative fitness of two strains containing either a sul1Δ or sul2Δ allele in S. cerevisiae (red) and S. uvarum (blue) respectively was determined in a pairwise manner within each species. The fitness was measured in the chemostat under sulfate-limited conditions against a strain containing sul2Δ or sul1Δ allele in S. cerevisiae (red) and S. uvarum (blue) respectively. The x-axis indicates which strains were competed and the bolded strain represents the more fit strain. The proportion of each strain was determined by monitoring canavanine resistance, which differentially marked the competing strains and has previously been shown to be neutral [25,39]. Each bar corresponds to the mean of 6 or more replicates ±SD. In S. cerevisiae, sul2Δ outcompetes sul1Δ and in S. uvarum sul1Δ outcompetes sul2Δ.