Wilke K, Jung M, Chen Y, Geldermann H
Institut für Tierhaltung und Tierzüchtung, Stuttgart, Germany.
Genomics. 1994 May 1;21(1):63-70. doi: 10.1006/geno.1994.1225.
Loci containing (GT)n repeats were isolated from three different plasmid libraries with inserts of porcine genomic DNA between 140 and 200, 200 and 300, and 350 and 400 bp. Sequencing showed that the average repeat length and the fraction of perfect repeats were increased in the libraries containing longer inserts (> or = 200 bp). The polymorphism of (GT)n loci containing at least 10 repeat units was analyzed using the polymerase chain reaction and an automated DNA sequencer. Nearly all tested loci are polymorphic and can therefore be used as marker loci for gene mapping and for other applications. The (GT)n loci were categorized into three classes: (1) loci containing the (GT)n repeats associated with a SINE element, (2) loci containing the (GT)n repeats associated with one or more other simple repeats, and (3) loci containing (GT)n as the only detected repetitive element. At most loci of the first class, the (GT)n repeat was in a fixed configuration adjacent to the 3' end of the SINE. The findings support the notion of clustering of different repeat types in the mammalian genome.
从三个不同的质粒文库中分离出含有(GT)n重复序列的基因座，这些文库中猪基因组DNA的插入片段大小分别在140至200、200至300以及350至400 bp之间。测序结果表明，在插入片段较长(≥200 bp)的文库中，平均重复长度和完美重复序列的比例有所增加。使用聚合酶链反应和自动DNA测序仪分析了含有至少10个重复单元的(GT)n基因座的多态性。几乎所有测试的基因座都是多态的，因此可作为基因定位和其他应用的标记基因座。(GT)n基因座可分为三类：(1) 含有与SINE元件相关的(GT)n重复序列的基因座；(2) 含有与一个或多个其他简单重复序列相关的(GT)n重复序列的基因座；(3) 含有(GT)n作为唯一检测到的重复元件的基因座。在第一类的大多数基因座中，(GT)n重复序列以固定构型位于SINE 3'端附近。这些发现支持了哺乳动物基因组中不同重复类型聚类的观点。
