Rates of intron loss and gain: Implications for early eukaryotic evolution
Rates of intron loss and gain: Implications for early eukaryotic evolution
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DOI：
10.1073/pnas.0500383102
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发表时间：
2005-04-19
影响因子：
11.1
通讯作者：
Gilbert, W
中科院分区：
文献类型：
--
作者：
Roy, SW;Gilbert, W
我们研究了来自七个不同真核生物基因组的684组同源基因的内含子-外显子结构，并提供了各种谱系中这些相同基因中内含子丢失和获得的速率和数量的最大似然估计。内含子损失率从每年约2 × 10（-9）到2 × 10（-10）不等。每年每个可能的内含子插入位点的增益率从6 × 10（-13）到4 × 10（-12）不等。内含子的损失率和损失率之间呈负相关，导致两个过程的损失率之比在世系之间有20倍的差异。观察到的内含子获得率不足以解释植物-动物祖先中估计存在的大量内含子，这表明早期真核生物中存在的内含子可能是通过与最近获得的内含子完全不同的过程产生的。
We study the intron-exon structures of 684 groups of orthologs from seven diverse eukaryotic genomes and provide maximum likelihood estimates for rates and numbers of intron losses and gains in these same genes for a variety of lineages. Rates of intron loss vary from approximate to 2 x 10(-9) to 2 X 10(-10) per year. Rates of gain vary from 6 x 10(-13) to 4 x 10(-12) per possible intron insertion site per year. There is an inverse correspondence between rates of intron loss and gain, leading to a 20-fold variation among lineages in the ratio of the rates of the two processes. The observed rates of intron gain are insufficient to explain the large number of introns estimated to have been present in the plant-animal ancestor, suggesting that introns present in early eukaryotes may have been created by a fundamentally different process than more recently gained introns.