Gene duplications in the prototypical cephalochordate amphioxus
Gene duplications in the prototypical cephalochordate amphioxus
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DOI：
10.1016/s0378-1119(01)00828-9
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发表时间：
2002-04-03
期刊：
影响因子：
3.5
通讯作者：
Garcia-Fernàndez, J
中科院分区：
文献类型：
--
作者：
Minguillón, C;Ferrier, DEK;Garcia-Fernàndez, J
进化发育生物学（Evo-Devo）这一新兴学科正面临着一个令人着迷的悖论，即用保守的片段或基因来解释形态进化，以构建不同的动物。头脊索文文鱼是现存的与脊椎动物最接近的近亲，具有简单的脊索动物身体计划，并且基因组直接来自于接近脊椎动物起源的全基因组复制之前的祖先。文昌鱼的形态可能保持相对不变，因为从脊椎动物谱系分化，但文昌鱼基因组并没有逃脱进化。我们报道了在文昌鱼基因组中分离出的第二个Emx基因（AmphiEmxB）。我们还认为，在文昌鱼的Hox群的后部可能发生了串联复制，从而产生了AmphiHox14，并讨论了脊索动物和脊椎动物祖先群的结构。此外，文文鱼谱系中Evx的串联复制产生了一个原型Evx基因（AmphiEvxA）和一个不再参与典型Evx功能的分化基因（AmphiEvxB）。文文鱼的这些特定基因复制的例子，以及这里总结的其他先前报道的复制，强调了文文鱼不是脊椎动物的祖先，而“只是”与祖先最接近的现存亲属，其基因组中混合了原型和文文鱼特有的特征。(C) 2002 Elsevier Science B.V.版权所有
The new discipline of Evolutionary Developmental Biology (Evo-Devo) is facing the fascinating paradox of explaining morphological evolution using conserved pieces or genes to build divergent animals. The cephalochordate amphioxus is the closest living relative to the vertebrates, with a simple, chordate body plan, and a genome directly descended from the ancestor prior to the genome-wide duplications that occurred close to the origin of vertebrates. Amphioxus morphology may have remained relatively invariant since the divergence from the vertebrate lineage, but the amphioxus genome has not escaped evolution. We report the isolation of a second Emx gene (AmphiEmxB) arising from an independent duplication in the amphioxus genome. We also argue that a tandem duplication probably occurred in the Posterior part of the Hox cluster in amphioxus, giving rise to AmphiHox14, and discuss the structure of the chordate and vertebrate ancestral clusters. Also, a tandem duplication of Evx in the amphioxus lineage produced a prototypical Evx gene (AmphiEvxA) and a divergent gene (AmphiEvxB), no longer involved in typical Evx functions. These examples of specific gene duplications in amphioxus, and other previously reported duplications summarized here, emphasize the fact that amphioxus is not the ancestor of the vertebrates but 'only' the closest living relative to the ancestor, with a mix of prototypical and amphioxus-specific features in its genome. (C) 2002 Elsevier Science B.V. All rights reserved.