Richards B, Horn G T, Merrill J J, Klinger K W
Department of Genetic Disease Research, Integrated Genetics, Inc., Framingham, Massachusetts.
Genomics. 1991 Feb;9(2):235-40. doi: 10.1016/0888-7543(91)90247-c.
The highly polymorphic VNTR locus pYNZ32 has been more extensively characterized, and its analysis converted to a rapid PCR-based format. DNA sequencing in the areas within and flanking the repeated segment allowed the design of specific amplification primers. The repeated region of pYNZ32 consists of an imperfectly duplicated 27-bp motif, 16 bases of which are more highly conserved. Allelic products from PCR amplification were resolved into nine different size classes ranging from approximately 1400 to 2200 bp. Additional polymorphism was revealed when the amplified products were analyzed by restriction enzyme digestion. Both the overall size variation and the internal sequence polymorphism were used to determine a heterozygosity value of 86% for YNZ32 in 50 unrelated individuals. The rapid analysis and improved resolution of amplified alleles on agarose gels, and the internal variability within YNZ32, increase its diagnostic utility as a VNTR and as a linkage marker for the nearby Huntington disease gene.
高度多态的可变数目串联重复序列（VNTR）位点pYNZ32已得到更广泛的表征，并且其分析已转换为基于聚合酶链反应（PCR）的快速方法。对重复片段内部及其侧翼区域进行DNA测序，从而设计出特异性扩增引物。pYNZ32的重复区域由一个不完全重复的27个碱基对的基序组成，其中16个碱基具有更高的保守性。PCR扩增产生的等位基因产物可分为9种不同的大小类别，范围约为1400至2200碱基对。当通过限制性酶切分析扩增产物时，发现了更多的多态性。利用总体大小变异和内部序列多态性，确定了50名无关个体中YNZ32的杂合度值为86%。在琼脂糖凝胶上对扩增等位基因进行快速分析并提高分辨率，以及YNZ32内部的变异性，增加了其作为VNTR以及作为附近亨廷顿病基因连锁标记的诊断效用。
