Whether nonessential genes evolve faster than essential genes has been a controversial issue. To resolve this issue, we use the data from a nearly complete set of single-gene deletions in the yeast Saccharomyces cerevisiae to assess protein dispensability. Also, instead of the nematode, which was used previously but is only distantly related to S. cerevisiae, we use another yeast, Candida albicans, as a second species to estimate the evolutionary distances between orthologous genes in two species. Our analysis reveals only a weak correlation between protein dispensability and evolutionary rate. More important, the correlation disappears when duplicate genes are removed from the analysis. And surprisingly, the average rate of nonsynonymous substitution is considerably lower than that for single-copy genes in the yeast genome. This observation suggests that structural constraints are more important in determining the rate of evolution of a protein than dispensability because duplicate genes are on average more dispensable than single-copy genes. For duplicate genes, those with only a weak effect or no effect of deletion on fitness evolve on average faster than those with a moderate or strong effect of deletion on fitness, which in turn evolve on average faster than those with a lethal effect of deletion.
|Evidence ID||Analyze ID||Interactor||Interactor Systematic Name||Interactor||Interactor Systematic Name||Type||Assay||Annotation||Action||Modification||Phenotype||Source||Reference||Note|
|Evidence ID||Analyze ID||Gene||Gene Systematic Name||Gene Ontology Term||Gene Ontology Term ID||Qualifier||Aspect||Method||Evidence||Source||Assigned On||Reference||Annotation Extension|
|Evidence ID||Analyze ID||Gene||Gene Systematic Name||Phenotype||Experiment Type||Experiment Type Category||Mutant Information||Strain Background||Chemical||Details||Reference|
|Evidence ID||Analyze ID||Regulator||Regulator Systematic Name||Target||Target Systematic Name||Experiment||Conditions||Strain||Source||Reference|