Jiang Enzhu, Zhang Siyi, Pang Hao
Department of Forensic Genetics and Biology, School of Forensic Medicine, China Medical University, No.77 Puhe Road, Shenyang North New Area, Shenyang, 110122, People's Republic of China.
Int J Legal Med. 2020 Jan;134(1):31-37. doi: 10.1007/s00414-019-02045-w. Epub 2019 May 6.
Degraded and low copy number (LCN) DNA samples are common challenging materials in forensic casework because they increase the difficulty of sample processing and reduce the possibility of obtaining genetic information from DNA. High-resolution melting (HRM) curve analysis is promising for genotyping genetic markers and has been applied to the detection of LCN and degraded DNA in the field of forensic science. However, the exact assessment based on HRM at multiple genetic markers from both degraded and LCN DNA materials has not been optimized. To explore the ability of HRM to genotype LCN and degraded DNA samples, we selected three genetic markers to genotype in experimental LCN and degraded DNA and practical hair shaft materials, which are often encountered as degraded and LCN DNA in forensic medicine. The results show that DNA samples of as low as 100 pg and as short as 60 bp were successfully genotyped by the HRM assay at all three genetic markers, whereas in hair shaft DNA, two loci were accurately genotyped. The HRM assay established in this study can be applied to LCN and degraded DNA analysis in forensic casework and can act as a reference point before genotyping short tandem repeat markers. Developing the HRM strategy for genotyping DNA genetic markers enriches detectable targets in hair shaft samples and provides valuable data for further exploration.
降解的和低拷贝数（LCN）DNA样本是法医案件工作中常见的具有挑战性的材料，因为它们增加了样本处理的难度，并降低了从DNA中获取遗传信息的可能性。高分辨率熔解（HRM）曲线分析在基因分型遗传标记方面很有前景，并且已应用于法医学领域中LCN和降解DNA的检测。然而，基于HRM对来自降解和LCN DNA材料的多个遗传标记进行的确切评估尚未得到优化。为了探索HRM对LCN和降解DNA样本进行基因分型的能力，我们选择了三个遗传标记，对实验性LCN和降解DNA以及实际毛发轴材料进行基因分型，这些材料在法医学中经常作为降解和LCN DNA出现。结果表明，在所有三个遗传标记上，通过HRM分析成功对低至100 pg和短至60 bp的DNA样本进行了基因分型，而在毛发轴DNA中，两个位点被准确基因分型。本研究中建立的HRM分析可应用于法医案件工作中的LCN和降解DNA分析，并可作为短串联重复标记基因分型前的参考点。开发用于DNA遗传标记基因分型的HRM策略丰富了毛发轴样本中的可检测目标，并为进一步探索提供了有价值的数据。
