Intragenic tandem repeats generate functional variability
Intragenic tandem repeats generate functional variability
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DOI：
10.1038/ng1618
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发表时间：
2005-09-01
期刊：
影响因子：
30.8
通讯作者：
Fink, GR
中科院分区：
文献类型：
--
作者：
Verstrepen, KJ;Jansen, A;Fink, GR
串联重复的DNA序列是基因组的高度动态组成部分（1）。大多数重复序列位于基因间区域，但也有一些位于编码序列或假基因中（2）。在人类中，基因内三联体重复序列的扩增与各种疾病相关，包括亨廷顿舞蹈病和脆性X综合征（3，4）。基因组中基因内重复序列的持续存在表明存在补偿性益处。在这里，我们表明，在酿酒酵母的基因组中，大多数含有基因内重复序列的基因编码细胞壁蛋白。重复序列触发基因中或基因与假基因之间的频繁重组事件，导致基因大小的扩增和收缩。这种大小变化造成表型的数量变化（例如，例如，在一个实施例中，粘附、絮凝或生物膜形成）。我们认为，基因内重复序列数的变化提供了细胞表面抗原的功能多样性，在真菌和其他病原体中，允许快速适应环境和增强宿主免疫系统。
Tandemly repeated DNA sequences are highly dynamic components of genomes(1). Most repeats are in intergenic regions, but some are in coding sequences or pseudogenes(2). In humans, expansion of intragenic triplet repeats is associated with various diseases, including Huntington chorea and fragile X syndrome(3,4). The persistence of intragenic repeats in genomes suggests that there is a compensating benefit. Here we show that in the genome of Saccharomyces cerevisiae, most genes containing intragenic repeats encode cell- wall proteins. The repeats trigger frequent recombination events in the gene or between the gene and a pseudogene, causing expansion and contraction in the gene size. This size variation creates quantitative alterations in phenotypes ( e. g., adhesion, flocculation or biofilm formation). We propose that variation in intragenic repeat number provides the functional diversity of cell surface antigens that, in fungi and other pathogens, allows rapid adaptation to the environment and elusion of the host immune system.