Genome evolution in S. cerevisiae

The dynamics of genome evolution in five unstressed lines of Saccharomyces cerevisiae evolving neutrally for approximately 2,200 generations was examined. Sequencing and analysis of 27 S. cerevisiae genomes at different time points of their evolutionary history unravelled a striking and complex distribution of mutations. We found that non-synonymous mutations accumulated linearly with time, in agreement with the neutral theory, but their effects presented evidence of selection. Our results shed light on the interplay dynamics of drift and selection, unearth complex patterns of genetic and protein interactions and contribute to the understanding of functional complementation and divergence between duplicated genes in S. cerevisiae.