Zurich Institute of Forensic Medicine, University of Zurich, Switzerland.
Functional Genomics Centre Zurich (FGCZ), University of Zurich/ETH Zurich, Switzerland.
Forensic Sci Int Genet. 2019 Nov;43:102149. doi: 10.1016/j.fsigen.2019.102149. Epub 2019 Aug 15.
Analysis of biological evidence typically begins with a preliminary screening for the presence of biological fluids, traditionally with enzymatic or immunologic tests and of late by RNA profiling. The goal of this study was to create a whole transcriptome protocol, to view potential degradation effects in forensically relevant body fluids. Total RNA from fresh and aged blood, menstrual blood, saliva, semen, skin and vaginal secretion was analyzed with a massively parallel sequencing method. Two RNA-Seq library protocols with and without rRNA depletion were tested and compared. The rRNA depletion step had a negative influence on the sequencing quality and on the downstream analyses. From the human and bacterial RNA sequences, source-specific signatures could be identified. Aged samples showed in general a higher level of RNA degradation and decreased bacterial diversity. In summary, we could show that transcriptional profiling and metagenome analysis are powerful tools to provide additional information about the trace evidence.
生物证据分析通常从初步筛选生物体液的存在开始，传统上采用酶或免疫检测方法，最近则采用 RNA 分析。本研究的目的是创建一个全转录组方案，以观察法医相关体液中潜在的降解效应。使用大规模平行测序方法分析新鲜和陈旧血液、月经血、唾液、精液、皮肤和阴道分泌物中的总 RNA。测试并比较了带有和不带有 rRNA 耗尽的两种 RNA-Seq 文库方案。rRNA 耗尽步骤对测序质量和下游分析有负面影响。从人类和细菌 RNA 序列中，可以识别出特定来源的特征。老化样本通常显示出更高水平的 RNA 降解和细菌多样性降低。总之，我们可以证明转录组分析和宏基因组分析是提供有关痕量证据的额外信息的有力工具。
