Lee Hwan Young, An Ja Hyun, Jung Sang-Eun, Oh Yu Na, Lee Eun Young, Choi Ajin, Yang Woo Ick, Shin Kyoung-Jin
Department of Forensic Medicine, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 120-752, South Korea.
Department of Forensic Medicine, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 120-752, South Korea.
Forensic Sci Int Genet. 2015 Jul;17:17-24. doi: 10.1016/j.fsigen.2015.03.002. Epub 2015 Mar 12.
The identification of body fluids found at crime scenes can contribute to solving crimes by providing important insights into crime scene reconstruction. In the present study, body fluid-specific epigenetic marker candidates were identified from genome-wide DNA methylation profiling of 42 body fluid samples including blood, saliva, semen, vaginal fluid and menstrual blood using the Illumina Infinium HumanMethylation450 BeadChip array. A total of 64 CpG sites were selected as body fluid-specific marker candidates by having more than 20% discrepancy in DNA methylation status between a certain type of body fluid and other types of body fluids and to have methylation or unmethylation pattern only in a particular type of body fluid. From further locus-specific methylation analysis in additional samples, 1 to 3 CpG sites were selected for each body fluid. Then, a multiplex methylation SNaPshot reaction was constructed to analyze methylation status of 8 body fluid-specific CpG sites. The developed multiplex reaction positively identifies blood, saliva, semen and the body fluid which originates from female reproductive organ in one reaction, and produces successful DNA methylation profiles in aged or mixed samples. Although it remains to be investigated whether this approach is more sensitive, more practical than RNA- or peptide-based assays and whether it can be successfully applied to forensic casework, the results of the present study will be useful for the forensic investigators dealing with body fluid samples.
对犯罪现场发现的体液进行鉴定，可为犯罪现场重建提供重要线索，从而有助于破案。在本研究中，使用Illumina Infinium HumanMethylation450 BeadChip芯片，通过对包括血液、唾液、精液、阴道分泌物和月经血在内的42份体液样本进行全基因组DNA甲基化分析，确定了体液特异性表观遗传标记候选物。共有64个CpG位点被选为体液特异性标记候选物，这些位点在某一种体液与其他类型体液之间的DNA甲基化状态差异超过20%，且仅在特定类型的体液中呈现甲基化或非甲基化模式。通过对更多样本进行进一步的位点特异性甲基化分析，每种体液选择了1至3个CpG位点。然后，构建了多重甲基化SNaPshot反应，以分析8个体液特异性CpG位点的甲基化状态。所开发的多重反应能够在一次反应中阳性鉴定出血液、唾液、精液以及源自女性生殖器官的体液，并能在老化或混合样本中成功生成DNA甲基化图谱。尽管这种方法是否比基于RNA或肽的检测方法更灵敏、更实用，以及是否能成功应用于法医案件工作仍有待研究，但本研究结果将对处理体液样本的法医调查人员有所帮助。
