Vergnaud G, Mariat D, Zoroastro M, Lauthier V
Centre d'Etudes du Bouchet, Vert le Petit, France.
Electrophoresis. 1991 Feb-Mar;12(2-3):134-40. doi: 10.1002/elps.1150120207.
Loci containing tandem repeats of short sequences are sometimes associated with a high level of polymorphism due to variations in the number of repeats. The different variants can be easily characterized by Southern blotting when the repeats span a range from a few hundred bases to a few kilobases, and probes derived from such tandem repeats constitute convenient genetic markers. These structures, usually called minisatellites, are best documented in the human genome, where their number has been estimated to be at least 1500. However, their role and mode of evolution are poorly understood. We are developing tools to evaluate the number of such redundant sequences in a genome and to gain access to new polymorphic loci. Our strategy is based on the use of polymers of oligonucleotides as DNA probes for hybridization on Southern blots. In a previous report, we made polymers with random units of 14 bp and showed that they detect multiple polymorphic loci on human genomic DNA. At present, we are testing the effect of an increase in the complexity of the polymer, as obtained by the use of a longer random unit, and the effect of slight sequence modifications to a particular tandem repeat sequence. In addition, some of these synthetic probes can detect a single polymorphic locus and directly provide new genetic markers.
包含短序列串联重复的基因座有时会由于重复次数的变化而与高水平的多态性相关。当重复序列跨度从几百个碱基到几千个碱基时，通过Southern印迹法可以很容易地鉴定出不同的变体，并且源自此类串联重复的探针构成了方便的遗传标记。这些结构通常被称为微卫星，在人类基因组中记录最为详尽，据估计其数量至少有1500个。然而，它们的作用和进化模式仍知之甚少。我们正在开发工具，以评估基因组中此类冗余序列的数量，并获取新的多态性基因座。我们的策略基于使用寡核苷酸聚合物作为DNA探针，用于Southern印迹杂交。在之前的一份报告中，我们制备了具有14个碱基随机单元的聚合物，并表明它们能检测人类基因组DNA上的多个多态性基因座。目前，我们正在测试通过使用更长的随机单元来增加聚合物复杂性的效果，以及对特定串联重复序列进行轻微序列修饰的效果。此外，其中一些合成探针可以检测单个多态性基因座，并直接提供新的遗传标记。
