Evolutionary dynamics of U12-type spliceosomal introns.
Evolutionary dynamics of U12-type spliceosomal introns.
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DOI：
10.1186/1471-2148-10-47
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发表时间：
2010-02-17
影响因子：
3.4
通讯作者：
Makałowski W
中科院分区：
文献类型：
--
作者：
Lin CF;Mount SM;Jarmołowski A;Makałowski W
许多多细胞真核生物具有两种类型的剪接体，用于从信使RNA前体中去除内含子。主要（U2）剪接体处理绝大多数内含子，称为U2型内含子，而次要（U12）剪接体去除一小部分（小于0.5%）内含子，称为U12型内含子。U12型内含子具有不同的序列元件，通常与U2型内含子一起出现在基因中。U12型内含子的系统发育分布表明，小剪接途径在真核生物进化中很早就出现了，并多次丢失。通过对U12型内含子簇的分析，研究了18种后生动物基因组中U12型内含子的进化。对获得、丢失和类型转换的研究表明，内含子类型在脊椎动物中是非常保守的。在180个内含子簇中，只有8个在任何脊椎动物物种中显示内含子丢失，只有5个显示U12和U2型之间的转换。虽然只有十九U12型内含子在果蝇，我们发现了一个U2到U12型转换的情况下，显然介导的隐蔽U12剪接位点的激活早期双翅目谱系。总体而言，U12型内含子的丢失比转化为U2型更常见，并且U12到U2的转化在GT-AG亚型的内含子中比在AT-AC亚型的内含子中更频繁地发生。我们还发现了支持天然U12型内含子与非典型的末端二核苷酸（CT-AC，GG-AG和GA-AG），以前没有报道。虽然完全丢失的U12型剪接体反复发生，U12内含子是非常稳定的一些类群，包括真兽目。U12内含子或含有它们的基因的丢失比转化为U2型更常见。天然U12型内含子中U12型末端二核苷酸的简并性比以前认为的要高。
Many multicellular eukaryotes have two types of spliceosomes for the removal of introns from messenger RNA precursors. The major (U2) spliceosome processes the vast majority of introns, referred to as U2-type introns, while the minor (U12) spliceosome removes a small fraction (less than 0.5%) of introns, referred to as U12-type introns. U12-type introns have distinct sequence elements and usually occur together in genes with U2-type introns. A phylogenetic distribution of U12-type introns shows that the minor splicing pathway appeared very early in eukaryotic evolution and has been lost repeatedly. We have investigated the evolution of U12-type introns among eighteen metazoan genomes by analyzing orthologous U12-type intron clusters. Examination of gain, loss, and type switching shows that intron type is remarkably conserved among vertebrates. Among 180 intron clusters, only eight show intron loss in any vertebrate species and only five show conversion between the U12 and the U2-type. Although there are only nineteen U12-type introns in Drosophila melanogaster, we found one case of U2 to U12-type conversion, apparently mediated by the activation of cryptic U12 splice sites early in the dipteran lineage. Overall, loss of U12-type introns is more common than conversion to U2-type and the U12 to U2 conversion occurs more frequently among introns of the GT-AG subtype than among introns of the AT-AC subtype. We also found support for natural U12-type introns with non-canonical terminal dinucleotides (CT-AC, GG-AG, and GA-AG) that have not been previously reported. Although complete loss of the U12-type spliceosome has occurred repeatedly, U12 introns are extremely stable in some taxa, including eutheria. Loss of U12 introns or the genes containing them is more common than conversion to the U2-type. The degeneracy of U12-type terminal dinucleotides among natural U12-type introns is higher than previously thought.
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影响因子：
11.4
作者：
Basu, Malay Kumar;Rogozin, Igor B.;Koonin, Eugene V.
通讯作者：
Koonin, Eugene V.
与U2内含子位置相比，在动物和植物之间，U12内含子位置更为强烈。
影响因子：
5.5
作者：
Basu, Malay Kumar;Makalowski, Wojciech;Rogozin, Igor B.;Koonin, Eugene V.
通讯作者：
Koonin, Eugene V.
影响因子：
4.3
作者：
Nguyen, Hung D.;Yoshihama, Maki;Kenmochi, Naoya
通讯作者：
Kenmochi, Naoya
影响因子：
30.8
作者：
McLysaght, A;Hokamp, K;Wolfe, KH
通讯作者：
Wolfe, KH
影响因子：
14.9
作者：
Maglott D;Ostell J;Pruitt KD;Tatusova T
通讯作者：
Tatusova T