Open and closed evolutionary paths for drastic morphological changes, involving serial gene duplication, sub-functionalization, and selection.
Open and closed evolutionary paths for drastic morphological changes, involving serial gene duplication, sub-functionalization, and selection.
复制标题
DOI：
10.1038/srep26838
复制
发表时间：
2016-05-25
影响因子：
4.6
通讯作者：
Ota KG
中科院分区：
文献类型：
--
作者：
Abe G;Lee SH;Li IJ;Chang CJ;Tamura K;Ota KG
双尾金鱼品系是在驯化过程中出现的剧烈形态变化的例子。虽然这种突变已知是由两个重复的脊索蛋白基因中的一个缺乏引起的，但尚不清楚为什么在其他驯化鱼类中没有观察到相同的突变。在这里，我们比较了单尾金鱼和普通鲤鱼（近亲，都经历了声带蛋白基因复制和驯化）的声带蛋白基因突变表型。morpholino诱导的敲低降低了两种物种的chordin基因表达；然而，敲除可使单尾金鱼产生双尾形态，但对普通鲤鱼形态无影响。这种差异可以通过观察到在普通鲤鱼中重复的chordin基因的表达模式完全重叠来解释，而在金鱼中则是亚功能化的。我们的发现表明，金鱼的剧烈形态变化可能是由随后发生的三种不同类型的进化事件（复制、亚功能化和选择）以一定的顺序加强的。
Twin-tail goldfish strains are examples of drastic morphological alterations that emerged through domestication. Although this mutation is known to be caused by deficiency of one of two duplicated chordin genes, it is unknown why equivalent mutations have not been observed in other domesticated fish species. Here, we compared the chordin gene morphant phenotypes of single-tail goldfish and common carp (close relatives, both of which underwent chordin gene duplication and domestication). Morpholino-induced knockdown depleted chordin gene expression in both species; however, while knockdown reproduced twin-tail morphology in single-tail goldfish, it had no effect on common carp morphology. This difference can be explained by the observation that expression patterns of the duplicated chordin genes overlap completely in common carp, but are sub-functionalized in goldfish. Our finding implies that goldfish drastic morphological changes might be enhanced by the subsequent occurrence of three different types of evolutionary event (duplication, sub-functionalization, and selection) in a certain order.