Walsh P S, Fildes N J, Reynolds R
Human Identity Group, Roche Molecular Systems Inc., Alameda, CA 94501, USA.
Nucleic Acids Res. 1996 Jul 15;24(14):2807-12. doi: 10.1093/nar/24.14.2807.
The PCR amplification of tetranucleotide short tandem repeat (STR) loci typically produces a minor product band 4 bp shorter than the corresponding main allele band; this is referred to as the stutter band. Sequence analysis of the main and stutter bands for two sample alleles of the STR locus vWA reveals that the stutter band lacks one repeat unit relative to the main allele. Sequencing results also indicate that the number and location of the different 4 bp repeat units vary between samples containing a typical verses low proportion of stutter product. The results also suggest that the proportion of stutter product relative to the main allele increases as the number of uninterrupted core repeat units increases. The sequence analysis and results obtained using various DNA polymerases appear to support the slipped strand displacement model as a potential explanation for how these stutter products are generated.
四核苷酸短串联重复序列（STR）位点的聚合酶链反应（PCR）扩增通常会产生一条比相应主等位基因带短4个碱基对的次要产物带；这被称为拖带。对STR位点vWA的两个样本等位基因的主带和拖带进行序列分析发现，拖带相对于主等位基因缺少一个重复单元。测序结果还表明，不同的4个碱基对重复单元的数量和位置在含有典型拖带产物比例与低比例拖带产物的样本之间有所不同。结果还表明，相对于主等位基因，拖带产物的比例随着不间断核心重复单元数量的增加而增加。使用各种DNA聚合酶进行的序列分析和获得的结果似乎支持滑动链位移模型，作为对这些拖带产物如何产生的一种潜在解释。
