Division of Legal Medicine, Department of Social Medicine, Nihon University School of Medicine, Tokyo, 1738610, Japan.
Mol Biol Rep. 2022 Feb;49(2):1017-1025. doi: 10.1007/s11033-021-06921-w. Epub 2021 Nov 5.
Hair is a frequently encountered biological evidence in personal identification. The amount of nuclear DNA that can be extracted from a single strand of rootless hair is most limited, making the detection of short tandem repeat (STR) polymorphisms difficult. To overcome these limitations, deletion/insertion polymorphisms (DIP) as a new type of genetic marker have shown their benefits in detecting low-copy-number DNA. The Investigator DIPplex kit contains 30 biallelic autosomal DIP and amelogenin. The analysis of DIPs combines the advantages of both STR and single nucleotide polymorphism analyses. Thus, this study aimed to detect the DIP distribution of individual hair shafts from individuals.
DNA was extracted from the shaft of fresh, aged, and shed hair. After DNA was evaluated, the DIP profiles were detected by capillary electrophoresis. The results indicated that the amount of DNA extracted from hair roots was much higher than that from the hair shafts in the same individual for all samples. The degradation index values of DNA from the aged hair shafts were highest. It is classified to be "mildly degraded." Compared with their hair roots, the full DIP profiles were detected for fresh hair, 70% for aged hair, and 92% for shed hair. Contrarily, except for fresh hair shafts, only three STR loci of the aged and shed strands of hair could be genotyped using AmpFlSTR MiniFiler PCR Amplification Kit.
These results indicate that the detection of DIP profile is an effective tool for personal identification from hair shafts, including aged hair.
毛发是个人识别中经常遇到的生物证据。从单根无根毛发中提取的核 DNA 量最为有限，这使得短串联重复序列（STR）多态性的检测变得困难。为了克服这些限制，缺失/插入多态性（DIP）作为一种新型遗传标记，在检测低拷贝数 DNA 方面显示出了优势。Investigator DIPplex 试剂盒包含 30 个双等位常染色体 DIP 和 amelogenin。DIP 的分析结合了 STR 和单核苷酸多态性分析的优势。因此，本研究旨在检测个体毛发的 DIP 分布。
从新鲜、陈旧和脱落的毛发中提取 DNA。在评估 DNA 后，通过毛细管电泳检测 DIP 图谱。结果表明，同一个体的发根提取的 DNA 量远高于同一个体的毛干。陈旧毛干的 DNA 降解指数值最高，被归类为“轻度降解”。与发根相比，新鲜毛发可以检测到完整的 DIP 图谱，陈旧毛发为 70%，脱落毛发为 92%。相比之下，除了新鲜毛发外，陈旧和脱落的毛发只能通过 AmpFlSTR MiniFiler PCR 扩增试剂盒检测到三个 STR 基因座。
这些结果表明，DIP 图谱的检测是一种从毛发（包括陈旧毛发）中进行个人识别的有效工具。
