[Molecular evolution of the ribonuclease A superfamily]

Ribonuclease A (RNASE A) superfamily is one of the model systems for studying new gene origin and functional innovations in evolutionary biology. Remarkably, gene duplications have been found in many members of RNASE A superfamily, and the functional differentiations of the duplicated genes have been demonstrated to be driven by the adaptive (positive) selection. In this review, we summarize the researches on the evolutionary patterns of RNASE A genes in differ-ent species, especially the recent researches at the genomic levels, suggesting a far more complex and intriguing evolution-ary diversity of RNASE A than previously thought. In the future, along with the increasing numbers of animal genomes available, the studies of RNASE A from more species are expected to reveal new evolutionary patterns and functional di-versifications, which will lay a foundation for the systematic studies on the molecular basis of adaptive evolution.