A computational scan for U12-dependent introns in the human genome sequence
A computational scan for U12-dependent introns in the human genome sequence
复制标题
DOI：
10.1093/nar/29.19.4006
复制
发表时间：
2001-10-01
影响因子：
14.9
通讯作者：
Durbin, R
中科院分区：
文献类型：
--
作者：
Levine, A;Durbin, R
依赖于U12的内含子在大多数真核生物基因组中只有少量存在，但它们的稀缺性使得对其性质的准确表征具有挑战性。使用人类基因组序列的草案版本进行了对U12依赖内含子的计算搜索。人类表达序列证实了人类基因组中404个U12依赖内含子，比之前在所有基因组中发现的非冗余U12依赖内含子的总数增加了6倍。虽然大多数内含子都有AT-AC或GT-AG末端二核苷酸，但也发现了少量末端具有惊人多样性的内含子，这表明在人类基因组中发现的许多非正则内含子可能是U12依赖内含子的变体，因此被微小剪接体剪接。与U2依赖内含子的比较表明，U12依赖内含子集缺乏U2依赖内含子的‘短内含子’峰特征。对这个依赖于U12的内含子集的分析证实了基因组中依赖于U12的内含子的偏向分布的报道，并使我们能够识别出几个替代剪接事件以及数量惊人的明显剪接错误。这一新的更大的U12依赖内含子的参考集将为未来研究U12剪接体的性质和进化提供资源。
U12-dependent introns are found in small numbers in most eukaryotic genomes, but their scarcity makes accurate characterisation of their properties challenging. A computational search for U12-dependent introns was performed using the draft version of the human genome sequence. Human expressed sequences confirmed 404 U12-dependent introns within the human genome, a 6-fold increase over the total number of non-redundant U12-dependent introns previously identified in all genomes. Although most of these introns had AT-AC or GT-AG terminal dinucleotides, small numbers of introns with a surprising diversity of termini were found, suggesting that many of the non-canonical introns found in the human genome may be variants of U12-dependent introns and, thus, spliced by the minor spliceosome. Comparisons with U2-dependent introns revealed that the U12-dependent intron set lacks the 'short intron' peak characteristic of U2-dependent introns. Analysis of this U12-dependent intron set confirmed reports of a biased distribution of U12-dependent introns in the genome and allowed the identification of several alternative splicing events as well as a surprising number of apparent splicing errors. This new larger reference set of U12-dependent introns will serve as a resource for future studies of both the properties and evolution of the U12 spliceosome.