Evaluation of skin- or sweat-characteristic mRNAs for inferring the human origin of touched contact traces
Evaluation of skin- or sweat-characteristic mRNAs for inferring the human origin of touched contact traces
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DOI：
10.1016/j.legalmed.2018.05.003
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发表时间：
2018-07-01
期刊：
影响因子：
1.5
通讯作者：
Sakurada, Koichi
中科院分区：
文献类型：
--
作者：
Akutsu, Tomoko;Watanabe, Ken;Sakurada, Koichi
当处理或触摸物体时，少量接触 DNA 会从皮肤转移到物体上，其来源可能是刑事案件法医分析中的一个问题。在这里，我们对皮肤或汗液特征 mRNA 进行了扩展评估，以研究它们推断物体是否被某人处理或触摸的可用性。首先，我们通过定量RT-PCR分析比较了皮肤拭子和其他体液之间候选基因的表达水平。在分析的基因中，根据其特异性和敏感性，选择了comodesmosin (CDSN)、晚期角质化包膜1C (LCE1C)、聚丝蛋白(FLG)、桥粒胶蛋白1和dermcidin进行进一步分析。然后，我们尝试从模拟案例样本中检测这些基因。因此，CDSN、LCE1C 和 FLG 由于其可检测性而可能成为良好的标记。最后，我们确定了这些基因的表达与皮肤拭子 DNA 产量之间的相关性，以评估它们作为接触 DNA 样本筛选测试的适应性。然而，这些基因的可检测性与皮肤拭子样本的 DNA 产量无关。总之，皮肤或汗液特征 mRNA CDSN、LCE1C 和 FLG 的基因表达分析可用于推断触摸接触痕迹的皮肤起源，但使用这些 mRNA 的表达水平来预测 DNA 产量是有问题的。为了开发接触 DNA 样本的筛选测试，应研究与 DNA 分析具有良好相关敏感性的其他标记。
The source of small amounts of touch DNA, which is transferred from the skin to an object when it is handled or touched, could be an issue in the forensic analysis of criminal cases. Here, we performed an extended evaluation of skin- or sweat-characteristic mRNAs to investigate their usability to infer whether an object has been handled or touched by someone. First, we compared the expression levels of candidate genes between skin swabs and other body fluids by quantitative RT-PCR analysis. Among the analyzed genes, comeodesmosin (CDSN), late cornified envelope 1C (LCE1C), filaggrin (FLG), desmocollin 1, and dermcidin were selected for further analysis on the basis of their specificities and sensitivities. Then, we tried to detect these genes from mock casework samples. As a result, CDSN, LCE1C, and FLG could be good markers because of their detectability. Finally, we determined the correlation between the expression of these genes and DNA yield of skin swabs to assess their adaptability as a screening test for touch DNA samples. However, the detectability of these genes was not correlated with the DNA yield of skin swab samples. In conclusion, gene expression analysis of the skin-or sweat characteristic mRNAs CDSN, LCE1C, and FLG could be useful for inferring the skin origin of touched contact traces, but the use of the expression levels of these mRNAs for the prediction of DNA yield is problematic. To develop a screening test for touch DNA samples, other markers that have a well-correlated sensitivity with DNA analysis should be investigated.