CNVs and gene essentiality

Copy number variants (CNVs) contribute to rapid evolutionary adaptation, but can also confer deleterious effects, and cause disease. Whereas the effects of amplifying individual genes or whole chromosomes (i.e., aneuploidy) have been studied extensively, much less is known about the genetic and functional effects of CNVs of varying sizes and structures. Here, we investigated seven Saccharomyces cerevisiae strains isolated from evolution experiments in glutamine-limited chemostats that have CNVs of variable structures all of which contain multiple copies of the gene GAP1 (described here:doi: 10.1128/mra.00729-22).We used transposon mutagenesis to investigate mutational tolerance and genetic interactions with CNVs. We profiled the transcriptome of each strain to identify signatures of CNV expression.