At the origin of spliceosomal introns: Is multiplication of introner-like elements the main mechanism of intron gain in fungi?
At the origin of spliceosomal introns: Is multiplication of introner-like elements the main mechanism of intron gain in fungi?
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DOI：
10.4161/cib.23147
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发表时间：
2013-03-01
影响因子：
--
通讯作者：
de Wit PJ
中科院分区：
文献类型：
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作者：
Collemare J;van der Burgt A;de Wit PJ
最近在六种真菌物种中发现的内含子样元件（ILEs）为研究规则剪接体内含子（RSIs）的起源和内含子获得的机制提供了新的思路。这些新的剪接体内含子在数百个拷贝中被发现，比rsi长，并且具有稳定的预测二级结构。然而，它们在序列和长度上容易退化，无法与rsi区分，这表明ILEs是大多数rsi的前身。在大多数真菌中，发现其他几乎相同的内含子在同一基因或不相关基因中复制的数量较少，表明内含子复制是一种普遍现象。然而，ILEs与大多数内含子增益有关，这表明其他类型的复制对内含子的总体增益不太重要。我们的数据支持了真菌中ILEs的增殖与内含子获得的主要机制相对应的假设。
The recent discovery of introner-like elements (ILEs) in six fungal species shed new light on the origin of regular spliceosomal introns (RSIs) and the mechanism of intron gains. These novel spliceosomal introns are found in hundreds of copies, are longer than RSIs and harbor stable predicted secondary structures. Yet, they are prone to degeneration in sequence and length to become undistinguishable from RSIs, suggesting that ILEs are predecessors of most RSIs. In most fungi, other near-identical introns were found duplicated in lower numbers in the same gene or in unrelated genes, indicating that intron duplication is a widespread phenomenon. However, ILEs are associated with the majority of intron gains, suggesting that the other types of duplication are of minor importance to the overall gains of introns. Our data support the hypothesis that ILEs’ multiplication corresponds to the main mechanism of intron gain in fungi.