Microsatellites in different eukaryotic genomes:: Survey and analysis
Microsatellites in different eukaryotic genomes:: Survey and analysis
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DOI：
10.1101/gr.10.7.967
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发表时间：
2000-07-01
期刊：
影响因子：
7
通讯作者：
Jurka, J
中科院分区：
文献类型：
--
作者：
Tóth, G;Gáspári, Z;Jurka, J
我们在几个真核生物分类类群中检测了具有重复单位长度为1-6个碱基对的微卫星的丰度：灵长类动物、啮齿动物、其他哺乳动物、非哺乳动物脊椎动物、节肢动物、秀丽隐杆线虫、植物、酵母和其他真菌。比较了外显子、内含子和基因间区简单序列重复序列的分布。三核苷酸和六核苷酸重复在所有分类群的蛋白质编码外显子中普遍存在，而重复丰度对重复单元长度的依赖表现出非常不同的模式，并且在基因间区域和内含子中表现出分类群特异性差异。虽然已知编码区和非编码区在微卫星分布上存在显著差异，但我们还可以证明基因间区和内含子之间存在特征差异。我们观察到惊人的（CCG）相对丰度(n)。（CGG）(n)三核苷酸在所有脊椎动物的基因间区域重复，而在内含子中几乎完全缺乏该基序。在简单序列基序的频率分布中也可以检测到分类群的特异性差异。我们的研究结果表明，单凭链滑移理论不足以解释微卫星在整个基因组中的分布。讨论了引起观测到的散度的其他可能因素。
We examined the abundance of microsatellites with repeated unit lengths of 1-6 base pairs in several eukaryotic taxonomic groups: primates, rodents, other mammals, nonmammalian vertebrates, arthropods, Caenorhabditis elegans, plants, yeast, and other fungi. Distribution of simple sequence repeats was compared between exons, introns, and intergenic regions. Tri- and hexanucleotide repeats prevail in protein-coding exons of all taxa, whereas the dependence of repeat abundance on the length of the repeated unit shows a very different pattenl as well as taxon-specific variation in intergenic regions and introns. Although it is known that coding and noncoding regions differ significantly in their microsatellite distribution, in addition we could demonstrate characteristic differences between intergenic regions and introns. We observed striking relative abundance of (CCG)(n) . (CGG)(n) trinucleotide repeats in intergenic regions of all vertebrates, in contrast to the almost complete lack of this motif from introns. Taxon-specific variation could also be detected in the frequency distributions of simple sequence motifs. Our results suggest that strand-slippage theories alone are insufficient to explain microsatellite distribution in the genome as a whole. Other possible factors contributing to the observed divergence are discussed.