Large-scale genome duplications and paralog divergence in fish

Based on fish genomic studies, we review mechanisms of divergence in duplicated genes (paralogs), resulted in small ("subfunctionalization") or large ("neofunctionalization") changes in paralogs. Gene divergence occurs due to several processes, such as non-synonymous substitutions, exon-intron structure rearrangement, and alterations in regulatory regions, which cause differential temporal or spatial expression of paralogous gene copies during ontogenesis.