U12 type introns were lost at multiple occasions during evolution.
U12 type introns were lost at multiple occasions during evolution.
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DOI：
10.1186/1471-2164-11-106
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发表时间：
2010-02-11
期刊：
影响因子：
4.4
通讯作者：
Samuelsson T
中科院分区：
文献类型：
--
作者：
Bartschat S;Samuelsson T
已知有两类内含子，常见的U2型和罕见的U12型。这两种类型的内含子被不同的剪接体去除。剪接体RNA的系统发育分布是U12剪接体的特征，即U11，U12，U4atac和U6atac RNA，表明U12剪接体在许多系统发育组中丢失。我们现在已经研究了U2和U12内含子在这些组中的分布。利用EST和基因组序列预测了U2和U12内含子。结果表明，在U12剪接体成分缺失的物种或分支中，也缺乏U12型内含子。例子是领鞭毛虫Monosiga brevicollis、溶组织内阿米巴、绿色藻类、硅藻和真菌谱系担子菌门。此外，而U12剪接不发生在秀丽隐杆线虫，U12内含子以及U12 snRNA存在于旋毛虫，这是深分支的线虫树。比较了T. spiralis和C. elegans揭示了U12内含子丢失的不同机制。U12内含子和剪接体RNA的系统发育分布进一步支持了U12依赖性剪接的早期起源。此外，这种分布确定了大量的情况下，在真核生物进化过程中，这种剪接丢失。
Two categories of introns are known, a common U2 type and a rare U12 type. These two types of introns are removed by distinct spliceosomes. The phylogenetic distribution of spliceosomal RNAs that are characteristic of the U12 spliceosome, i.e. the U11, U12, U4atac and U6atac RNAs, suggest that U12 spliceosomes were lost in many phylogenetic groups. We have now examined the distribution of U2 and U12 introns in many of these groups. U2 and U12 introns were predicted by making use of available EST and genomic sequences. The results show that in species or branches where U12 spliceosomal components are missing, also U12 type of introns are lacking. Examples are the choanoflagellate Monosiga brevicollis, Entamoeba histolytica, green algae, diatoms, and the fungal lineage Basidiomycota. Furthermore, whereas U12 splicing does not occur in Caenorhabditis elegans, U12 introns as well as U12 snRNAs are present in Trichinella spiralis, which is deeply branching in the nematode tree. A comparison of homologous genes in T. spiralis and C. elegans revealed different mechanisms whereby U12 introns were lost. The phylogenetic distribution of U12 introns and spliceosomal RNAs give further support to an early origin of U12 dependent splicing. In addition, this distribution identifies a large number of instances during eukaryotic evolution where such splicing was lost.
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DOI：
10.1093/bfgp/elp002
发表时间：
2009-01-01
期刊：
Briefings in Functional Genomics & Proteomics
影响因子：
--
作者：
Meyer, Markus;Vilardell, Josep
通讯作者：
Vilardell, Josep
影响因子：
10.5
作者：
PIERANDREIAMALDI, P;BOZZONI, I;CARDINALI, B
通讯作者：
CARDINALI, B
影响因子：
3.4
作者：
Russell AG;Shutt TE;Watkins RF;Gray MW
通讯作者：
Gray MW
影响因子：
64.8
作者：
Russell, Anthony G.;Charette, J. Michael;Gray, Michael W.
通讯作者：
Gray, Michael W.
影响因子：
14.9
作者：
Zhu, W;Brendel, V
通讯作者：
Brendel, V