Phylogenetic timing of the fish-specific genome duplication correlates with the diversification of teleost fish
Phylogenetic timing of the fish-specific genome duplication correlates with the diversification of teleost fish
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DOI：
10.1007/s00239-004-2613-z
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发表时间：
2004-08-01
影响因子：
3.9
通讯作者：
Meyer, A
中科院分区：
文献类型：
--
作者：
Hoegg, S;Brinkmann, H;Meyer, A
对于许多基因，辐鳍鱼有两个旁系同源的副本，其中只有一个直系同源物存在于四足动物中。在硬骨鱼类（斑马鱼、河豚、青鳉和慈鲷）中发现了一组几乎完整的Hox簇，但在基底的辐鳍类谱系（Polypterus）中没有发现，这导致了鱼类特异性基因组复制假说的形成。这种基因组复制的进化过程中的射线鳍鱼的系统发育时间是未知的，因为只有少数几个物种的基础鱼类谱系已被调查到目前为止。在这项研究中，三个核基因（fzd8，sox11，酪氨酸酶）的序列从鲟鱼（鲟形目），加尔斯（Semionotiformes），骨舌（骨舌），和一个tenpounder（Elopomorpha）。对于这三个基因，先前已经在硬骨鱼中描述了两个拷贝（例如，斑马鱼，河豚），但只有一个orthopathic副本中发现四足动物。这三个基因的个体基因树和一个串联的数据集支持这一假设，即鱼类特异性基因组重复事件发生在鲟形目和半形目从导致硬骨鱼的谱系分裂之后，但在骨舌形目分化之前。如果这三个基因在所提出的鱼类特异性基因组复制事件中被复制，那么这个事件将物种贫乏的早期分支谱系与物种丰富的硬骨鱼谱系分开。这一事件所产生的额外数量的基因可能促进了进化辐射和硬骨鱼的表型多样化。
For many genes, ray-finned fish (Actinopterygii) have two paralogous copies, where only one ortholog is present in tetrapods. The discovery of an additional, almost-complete set of Hox clusters in teleosts (zebrafish, pufferfish, medaka, and cichlid) but not in basal actinopterygian lineages (Polypterus) led to the formulation of the fish-specific genome duplication hypothesis. The phylogenetic timing of this genome duplication during the evolution of ray-finned fish is unknown, since only a few species of basal fish lineages have been investigated so far. In this study, three nuclear genes (fzd8, sox11, tyrosinase) were sequenced from sturgeons (Acipenseriformes), gars (Semionotiformes), bony tongues (Osteoglossomorpha), and a tenpounder (Elopomorpha). For these three genes, two copies have been described previously teleosts (e.g., zebrafish, pufferfish), but only one orthologous copy is found in tetrapods. Individual gene trees for these three genes and a concatenated dataset support the hypothesis that the fish-specific genome duplication event took place after the split of the Acipenseriformes and the Semionotiformes from the lineage leading to teleost fish but before the divergence of Osteoglossiformes. If these three genes were duplicated during the proposed fish-specific genome duplication event, then this event separates the species-poor early-branching lineages from the species-rich teleost lineage. The additional number of genes resulting from this event might have facilitated the evolutionary radiation and the phenotypic diversification of the teleost fish.