辐鳍鱼类是脊椎动物中种类最多、分布最广的类群,其基因组大小不等。过去的观点认为,在脊椎动物进化历程中曾发生了两次基因组复制。近期的系统基凶组学研究资料进一步提出,在大约350百万年,辐鳍鱼还发生了第二次基因组复制,即鱼类特异的基因组复制(fish-specific genome duplication,FSGD),且发生的时间正处在“物种极度丰富”的硬骨鱼谱系(真骨总目)和“物种贫乏”的谱系(辐鳍鱼纲基部的类群)出现分歧的时间点,表明FSGD与硬骨伍物种和生物多样性的增加有关。进一步开展鱼类比较基因组学和功能基因组学研究将进一步验证FSGD这一假说。
The ray-finned fishes are the most diverse and successful within the vertebrates anti their genomes vary widely in size. Previous studies suggested that two rounds of genome duplications have been involved in vertebrate evolution.The recent studies on comparative genomics have further suggested that a third round of fish-specific genome duplication (FSGD) in ray-finned (aetinopterygian) fishes might have occurred at about 350 million years ago, during the divergence between teleost fish and basal actinopterygian lineages. Therefore, FSGD might be related to the increase in species number anti biological diversity during this time. Further studies on comparative genomics and functional genomies will be needed to confirm the hypothesis.