Late changes in spliceosomal introns define clades in vertebrate evolution
Late changes in spliceosomal introns define clades in vertebrate evolution
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DOI：
10.1073/pnas.96.18.10267
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发表时间：
1999-08-31
影响因子：
11.1
通讯作者：
Brenner, S
中科院分区：
文献类型：
--
作者：
Venkatesh, B;Ning, Y;Brenner, S
剪接体内含子的进化起源一直是备受争议的话题。内含子被认为在进化过程中既丢失又获得。如果内含子的获得或丢失是进化中的独特事件，则它们可以作为系统发育分析的标记。我们已经做了一个广泛的调查7剪接体内含子的系统发育分布，是存在于河豚基因，但不是在他们的哺乳动物同源物，我们表明，这些内含子被收购的actinopterygian（射线鳍）鱼类在不同的进化阶段。我们还研究了鱼类视紫红质基因的内含子模式，并表明，在祖先脊索动物视紫红质基因中发现的四个内含子同时丢失在一个共同的祖先鳍鱼。内含子中的这些变化作为系统发育分析的极好标记，因为它们可靠地定义了进化枝。我们的内含子为基础的分支图建立了一些射线鳍鱼类难以确定的系统发育关系。例如，它表明，bichirs（Polypterus）是所有其他现存的鳍鱼的姐妹群。
The evolutionary origin of spliceosomal introns has been the subject of much controversy. Introns are proposed to have been both lost and gained during evolution. If the gain or loss of introns are unique events in evolution, they can serve as markers for phylogenetic analysis. We have made an extensive survey of the phylogenetic distribution of seven spliceosomal introns that are present in Fugu genes, but not in their mammalian homologues; we show that these introns were acquired by actinopterygian (ray-finned) fishes at various stages of evolution. We have also investigated the intron pattern of the rhodopsin gene in fishes, and show that the four introns found in the ancestral chordate rhodopsin gene were simultaneously lost in a common ancestor of ray-finned fishes. These changes in introns serve as excellent markers for phylogenetic analysis because they reliably define clades. Our intron-based cladogram establishes the difficult-to-ascertain phylogenetic relationships of some ray-finned fishes. For example, it shows that bichirs (Polypterus) are the sister group of all other extant ray-finned fishes.