| 要旨 |
Gene duplication and subsequent divergence have long been believed to be of importance for function novelty and complexity of organism. Neofunctionalization model describing duplicated gene evolution predicts that two copies have equal chance to accelerate in evolutionary rate because of neutral evolution mainly due to function redundancy, whereas subfunctionalization model predicts that there is no acceleration of evolutionary rate for comparison of two copies. Here, we present evidence from genes on human sex chromosomes and duplicated genes in yeast genome for asymmetry in evolutionary rate of duplicated genes, that is, the acceleration of evolutionary rate in one copy depends on the local recombination rate. These results are consistent with prediction of population genetics theory if two copies are not non-redundant from the start due to selection for increased dosage and under purifying selection after gene duplication. Therefore, besides neofunctionalization and subfunctionalization models, recombination should be taken into account in research on evolution of duplicated genes.
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