串联重复

串联重复（英语：Tandem repeats）是指DNA中的一个或多个核苷酸前后相连接的重复。一个例子：其中的ATTCG在这里重复了三次。几种蛋白质结构域也是由串联重复的氨基酸序列产生，如犰狳重复（英语：Armadillo repeats）。但很少有串联重复出现在体内的蛋白质中，多数为人工设计的蛋白。当重复核苷酸数在10到60之间时，被称为小卫星，低于10则被称为短串联重复或微卫星。重复核苷酸只有两个时，称为“双核苷酸重复”（如：ACACACAC…）。遗传性非息肉病性结直肠癌（英语：Hereditary nonpolyposis colorectal cancer）的微卫星不稳定性（英语：microsatellite instability）常为这种类型。当重复核苷酸有三个时，称为“三核苷酸重复”（如：CAGCAGCAGCAG…）在这一区域的异常常导致三核苷酸重复疾病（英语：Trinucleotide repeat disorder）。当重复单元的拷贝数在人群中存在不同时。被称为可变数目串联重复序列（VNTR）。串联重复可以作为确定个体的遗传特征的一种描述模式，在确定亲子关系中非常有用。短串联重复序列可用于一些系谱DNA检验（英语：genealogical DNA test）。DNA is examined from microsatellites within the chromosomal DNA. Minisatellite is another way of saying special regions of the loci. Polymerase chain reaction (or PCR) is performed on the minisatellite areas. The PCR must be performed on each organism being tested. The amplified material is then run through electrophoresis. By checking the percentage of bands that match, parentage is determined.Polymorphic tandem repeats (alias VNTRs) are also present in microorganisms and can be used to trace the origin of an outbreak. The corresponding assay in which a collection of VNTRs is typed to characterize a strain is most often called MLVA (Multiple Loci VNTR Analysis).In the field of Computer Science, tandem repeats in strings (e.g., DNA sequences) can be efficiently detected using suffix trees or suffix arrays.Studies in 2004 linked the unusual genetic plasticity of dogs to mutations in tandem repeats.