Intron phase correlations and the evolution of the intron exon structure of genes
Intron phase correlations and the evolution of the intron exon structure of genes
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DOI：
10.1073/pnas.92.26.12495
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发表时间：
1995-12-19
影响因子：
11.1
通讯作者：
Gilbert, W
中科院分区：
文献类型：
--
作者：
Long, MY;Rosenberg, C;Gilbert, W
基因内含子/外显子结构进化中的两个问题是外显子改组的作用和内含子的起源。使用一个大的真核生物含内含子基因的数据库，我们已经发现，有内含子相位之间的相关性，导致过量的对称外显子和对称外显子集。我们解释这些过剩的表现外显子改组，并作出保守估计，至少有19%的外显子在数据库中参与外显子改组，这表明外显子改组在进化中的重要作用。此外，这些对称外显子的过剩也出现在真核基因中与原核基因同源的那些区域：古老的保守区域。这最后一个事实不能用内含子插入理论来解释，而是支持一些内含子是古老的概念，即基因的外显子理论。
Two issues in the evolution of the intron/ exon structure of genes are the role of exon shuffling and the origin of introns. Using a large data base of eukaryotic intron-containing genes, we have found that there are correlations between intron phases leading to an excess of symmetric exons and symmetric exon sets. We interpret these excesses as manifestations of exon shuffling and make a conservative estimate that at least 19% of the exons in the data base were involved in exon shuffling, suggesting an important role for exon shuffling in evolution. Furthermore, these excesses of symmetric exons appear also in those regions of eukaryotic genes that are homologous to prokaryotic genes: the ancient conserved regions. This last fact cannot be explained in terms of the insertional theory of introns but rather supports the concept that some of the introns were ancient, the exon theory of genes.