Intron-exon structures of eukaryotic model organisms
Intron-exon structures of eukaryotic model organisms
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DOI：
10.1093/nar/27.15.3219
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发表时间：
1999-08-01
影响因子：
14.9
通讯作者：
Long, M
中科院分区：
文献类型：
--
作者：
Deutsch, M;Long, M
为了研究真核生物基因内含子-外显子结构的分布，我们构建了一个通用的外显子数据库，该数据库包含了10种真核模式生物的所有含内含子的基因和外显子数据库：智人、小家鼠、原鸡、褐家鼠、拟南芥、玉米、粟酒裂殖酵母、曲霉、秀丽隐杆线虫和果蝇。我们清除了冗余基因，以避免数据库中冗余可能带来的偏倚。剔除不含正确剪接位点的可疑内含子后，最终数据库包含17102个内含子、21019个外显子和2903个独立或准独立基因，平均每个真核基因每kb编码区包含3.7个内含子。外显子分布在30-40个残基左右达到峰值，大多数内含子长40-125 nt。10个模式生物的可变内含子-外显子结构揭示了两个有趣的统计现象，这对以前的一些猜测投光。(i)基因组大小似乎与每个基因的总内含子长度相关。例如，无脊椎动物的内含子比人类基因的内含子小，而酵母内含子比无脊椎动物的内含子短，然而，这种相关性很弱，这表明除了基因组大小之外的其他因素也可能影响内含子大小。(ii)小于50 nt的内含子比更长的内含子明显更不常见，这可能是由于内含子剪接的最小内含子大小要求。
To investigate the distribution of intron-exon structures of eukaryotic genes, we have constructed a general exon database comprising ail available intron-containing genes and exon databases from 10 eukaryotic model organisms: Homo sapiens, Mus musculus, Gallus gallus, Rattus norvegicus, Arabidopsis thaliana, Zea mays, Schirosaccharomyces pombe, Aspergillus, Caenorhabditis elegans and Drosophila. We purged redundant genes to avoid the possible bias brought about by redundancy in the databases. After discarding those questionable introns that do not contain correct splice sites, the final database contained 17 102 introns, 21 019 exons and 2903 independent or quasi-independent genes, On average, a eukaryotic gene contains 3.7 introns per kb protein coding region. The exon distribution peaks around 30-40 residues and most introns are 40-125 nt long. The variable intron-exon structures of the 10 model organisms reveal two interesting statistical phenomena, which cast light on some previous speculations. (i) Genome size seems to be correlated with total intron length per gene. For example, invertebrate introns are smaller than those of human genes, while yeast introns are shorter than invertebrate introns, However, this correlation is weak, suggesting that other factors besides genome size may also affect intron size. (ii) Introns smaller than 50 nt are significantly less frequent than longer introns, possibly resulting from a minimum intron size requirement for intron splicing.