Mason Katelyn E, Paul Phillip H, Chu Fanny, Anex Deon S, Hart Bradley R
Forensic Science Center, Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, CA, 94550.
Department of Chemistry, Michigan State University, 578 S Shaw Ln, East Lansing, MI, 48824.
J Forensic Sci. 2019 Jul;64(4):1152-1159. doi: 10.1111/1556-4029.13995. Epub 2019 Feb 8.
Shed human hair (lacking root nuclear DNA) frequently contributes important information to forensic investigations involving human identification. Detection of genetic variation observed in amino acid sequences of hair proteins provides a new suite of identity markers that augment microscopic hair analysis and mitochondrial DNA sequencing. In this study, a new method that completely dissolves single hairs using a combination of heat, ultrasonication, and surfactants was developed. Dissolved proteins were digested and genetically variant peptide (GVP) profiles were obtained for single hairs (25 mm) via high-resolution nanoflow liquid chromatography-based mass spectrometry and a novel exome-driven bioinformatic approach. Overall, 6519 unique peptides were identified and a total of 57 GVPs were confirmed. Random match probabilities ranged between 2.6 × 10 and 6.0 × 10 . The new bioinformatic strategy and ability to analyze GVPs in forensically relevant samples sizes demonstrate applicability of this approach to distinguish individuals in forensic contexts.
脱落的人类毛发（缺乏根部核DNA）常常为涉及人类身份识别的法医调查提供重要信息。在毛发蛋白质氨基酸序列中观察到的遗传变异检测提供了一套新的身份标记，可增强微观毛发分析和线粒体DNA测序。在本研究中，开发了一种使用加热、超声处理和表面活性剂组合完全溶解单根毛发的新方法。溶解的蛋白质经消化后，通过基于高分辨率纳流液相色谱的质谱法和一种新型外显子驱动的生物信息学方法获得单根毛发（25毫米）的基因变异肽（GVP）谱。总体而言，鉴定出6519种独特肽，共确认57种GVP。随机匹配概率在2.6×10至6.0×10之间。新的生物信息学策略以及在法医相关样本量中分析GVP的能力证明了该方法在法医背景下区分个体的适用性。
