Genome and gene duplications and gene expression divergence: a view from plants.

With many plant genomes sequenced, it is now clear that one distinguishing feature of angiosperm (flowering plant) genomes is their high frequency of whole-genome duplication. Single-gene duplication is also widespread in angiosperm genomes. Following various mechanisms of gene duplication, genes are often retained or lost in a biased manner, which has suggested recent models for gene family evolution, such as functional buffering and the gene balance hypothesis in addition to now-classical models, including neofunctionalization and subfunctionalization. Evolutionary consequences of gene duplication, often studied through analyzing gene expression divergence, have enhanced understanding of the biological significance of different mechanisms of gene duplication.