Phillips C, Rodriguez A, Mosquera-Miguel A, Fondevila M, Porras-Hurtado L, Rondon F, Salas A, Carracedo A, Lareu M V
Genomic Medicine Group, CIBERER, University of Santiago de Compostela, Galicia, Spain.
Forensic Sci Int Genet. 2008 Dec;3(1):7-13. doi: 10.1016/j.fsigen.2008.07.002. Epub 2008 Aug 26.
The simple tetrameric STR D9S1120 exhibits a common population-specific allele of 9 repeats (9RA) reported to have an average frequency of 0.36 in Native Americans from both North and South of the continent. Apart from the presence of 9RA in two northeast Siberian populations, D9S1120 shows variability exclusive to, and universal in all American populations studied to date. This STR therefore provides an informative forensic marker applicable in countries with significant proportions of Native American populations or ancestry. We have re-designed PCR primers that reduce the amplified product sizes reported in NCBI UniSTS by more than a third and have characterized the repeat structure of D9S1120. The 9RA allele shares the same repeat structure as the majority of other D9S1120 alleles and so originates from a slippage-diminution mutation rather than an independent deletion. We confirm the previously reported allele frequencies from a range of populations indicating a global heterozygosity range for D9S1120 of 66-75% and estimate the proportion of Native American-diagnostic genotypes to average 53%, underlining the potential usefulness of this STR in both forensic identification and in population genetics studies of the Americas.
简单的四聚体短串联重复序列D9S1120表现出一种常见的群体特异性等位基因，即9次重复（9RA），据报道，在北美和南美大陆的美洲原住民中，其平均频率为0.36。除了在两个西伯利亚东北部群体中存在9RA外，D9S1120在所有迄今研究的美洲群体中都表现出特有的变异性。因此，这个短串联重复序列提供了一个信息丰富的法医标记，适用于美洲原住民人口或血统比例较高的国家。我们重新设计了聚合酶链反应（PCR）引物，使美国国立生物技术信息中心（NCBI）的通用序列标签系统（UniSTS）中报道的扩增产物大小减少了三分之一以上，并对D9S1120的重复结构进行了表征。9RA等位基因与大多数其他D9S1120等位基因具有相同的重复结构，因此它起源于滑动减少突变，而非独立缺失。我们证实了先前报道的一系列群体的等位基因频率，表明D9S1120的全球杂合度范围为66%-75%，并估计美洲原住民诊断基因型的比例平均为53%，这突出了该短串联重复序列在法医鉴定和美洲群体遗传学研究中的潜在用途。
