Department of Oral and Maxillofacial Surgery, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi. 1110 Shimo-kato, Chuo, Yamanashi 409-3898, Japan; Department of Legal Medicine, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi. 1110 Shimo-kato, Chuo, Yamanashi 409-3898, Japan.
Department of Legal Medicine, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi. 1110 Shimo-kato, Chuo, Yamanashi 409-3898, Japan; Laboratory of Systems Genomics, Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5, Kashiwanoha, Kashiwa, Chiba 272-8562, Japan.
Leg Med (Tokyo). 2022 Nov;59:102136. doi: 10.1016/j.legalmed.2022.102136. Epub 2022 Aug 22.
Sex determination is a crucial factor in the identification of unidentified human remains. Sex determination by DNA analysis is particularly useful because it can be applied to samples for which morphological characteristics are unavailable. Because samples handled in forensic DNA typing are easily degraded by environmental factors and microorganisms, there is a need for a method that can accurately determine sex even in highly decayed samples. Previous studies mainly used sex differences in an intron of the amelogenin gene. However, this region is highly polymorphic, and there are cases where accurate sexing cannot be performed because of genetic mutations in the target region. Thus, for reliable sex determination, it is desirable to select loci with as few non-sexual polymorphisms as possible. In this study, we focused on the exon 1 region of the amelogenin gene, which has very little polymorphism other than sex differences. We developed a primer set for sex determination and compared it with the GlobalFiler™ PCR Amplification Kit (GF), which is widely used for forensic DNA typing. The results showed that the amount of DNA required for accurate sex determination was 25 pg for both methods, achieving equivalent sensitivity. Next, we compared the two methods using ancient human skeletons and found that the present method with its shorter amplicon was considerably superior to GF. The present method is simple, rapid, inexpensive, and suitable for analyzing highly degraded samples. Therefore, this method is expected to contribute to forensic sciences and physical anthropology.
性别鉴定是确定无名遗体身份的关键因素。通过 DNA 分析进行性别鉴定特别有用，因为它可以应用于没有形态特征的样本。由于法医 DNA 分型中处理的样本容易受到环境因素和微生物的降解，因此需要一种即使在高度腐烂的样本中也能准确鉴定性别的方法。以前的研究主要使用牙釉蛋白基因内含子的性别差异。然而，该区域高度多态性，并且由于目标区域的基因突变，存在无法准确进行性别鉴定的情况。因此，为了进行可靠的性别鉴定，最好选择性别差异以外的非性多态性尽可能少的基因座。在这项研究中，我们专注于牙釉蛋白基因的外显子 1 区域，除了性别差异外，该区域的多态性非常少。我们开发了用于性别鉴定的引物组，并将其与广泛用于法医 DNA 分型的 GlobalFiler™ PCR 扩增试剂盒 (GF) 进行了比较。结果表明，两种方法准确进行性别鉴定所需的 DNA 量均为 25pg，具有等效的灵敏度。接下来，我们使用古代人类骨骼比较了这两种方法，发现具有较短扩增子的本方法明显优于 GF。本方法简单、快速、廉价，适合分析高度降解的样本。因此，该方法有望为法医学和体质人类学做出贡献。
