Aneuploidy confers quantitative proteome changes and phenotypic variation in budding yeast

Aneuploidy, the presence of an abnormal number of chromosomes, has been associated with developmental defects and cancer, but also with adaptive evolution in experimental organisms. Recent studies raised doubts over whether aneuploidy affects gene expression at the proteome level or whether it can bring phenotypic variation and improved fitness over euploid counterparts. A profiling study of a large set of aneuploid yeast strains grown under a variety of conditions demonstrates that aneuploidy can affect both the transcriptome and the proteome, and generate significant phenotypic variation that can lead to fitness gains.