Point mutations of homologs as an adaptive solution to the gene loss

Gene loss is common and influences genome evolution trajectories.Multiple adaptive strategies to compensate for gene loss have been observed,including copy number gain of paralogous genes and mutations in genes of the same pathway.By using the Ubl-specific protease 2(ULP2)eviction model,we identify compensatory mutations in the homologous gene ULP1 by laboratory evolution and find that these mutations are capable of rescuing defects caused by the loss of ULP2.Furthermore,bioinformatics analysis of genomes of yeast gene knockout library and natural yeast isolate datasets suggests that point mutations of a homologous gene might be an additional mechanism to compensate for gene loss.