Abstract: Objective The aim of this study is to obtain expression profiles of long RNA of five forensic body fluids by transcriptome sequencing, and explore prospective RNA markers for body fluid identification (BFID) and individual identification of body fluid donors. Methods The long RNAs of peripheral blood, semen, vaginal secretion and menstrual blood samples collected from five volunteers and saliva collected from nine volunteers were enriched by rRNA depletion, followed by library preparation and sequencing. Differential gene expression analysis was performed between each two of the five body fluids to identify body fluid-specific genes which show expression difference with the others. The body fluid specificity of target genes was evaluated via real-time fluorescence quantitative PCR（qPCR）. Results The expression profiles of mRNA, lncRNA and circRNA were obtained from five body fluids, and a total of 19 942 mRNAs, 42 206 lncRNAs and 151 927 circRNAs were detected. The differential gene expression analysis indicates 4 091 mRNAs, 1 052 lncRNAs and 855 circRNAs with potential body fluid specificity. A total of 48 genes were selected with stable expression in target body fluid and significant differential expression with the others, and their specificity were validated by qPCR. Among these BFID markers, 38 were novel genes, including 23 specific mRNAs, 3 specific lncRNAs and 12 specific circRNAs. Conclusion Our study measures the long RNA expression profiles in five forensic body fluids, explores a series of novel RNA markers with body fluid specificity and abundant RNA polymorphisms, and provides a candidate gene list with cSNP for body fluid identification and individual identification in forensic medicine.

Key words: forensic genetics, body fluid identification, transcriptome sequencing, RNA, qPCR

摘要： 目的 利用转录组测序获取体液斑长链RNA转录谱，从中筛选具有体液鉴定和体液供者个体识别应用前景的RNA标志物。 方法 收集外周血、精液、阴道分泌物和月经血各5例样本以及9例唾液样本并提取总RNA，去除核糖体RNA以富集样本的信使RNA（messenger RNA，mRNA）、长链非编码RNA（long non-coding RNA，lncRNA）以及环状RNA（circular RNA，circRNA），构建转录组文库并测序，获得5种体液的长链RNA表达谱。随后，对5种体液样本进行体液差异表达分析，筛选出与其余体液样本均存在显著表达差异的体液特异性基因，并利用实时荧光定量PCR（real-time fluorescence quantitative PCR，qPCR）验证基因的体液特异性。 结果 经过对5种体液mRNA、lncRNA和circRNA表达谱的刻画，共发现了19 942个mRNA、42 206个lncRNA和151 927个circRNA，并通过差异分析识别出了4 091个体液特异性mRNA、1 052个特异性lncRNA和855个特异性circRNA。从上述候选特异性基因中筛选出目标体液中表达稳定且与其余体液表达差异显著的48个基因，利用qPCR完成其体液特异性的初步验证，其中过往未曾报道的体液特异性基因有38个，包括23个特异性mRNA、3个特异性lncRNA和12个特异性circRNA。结论 本研究绘制了5种法医学常见体液的长链RNA表达谱，挖掘了大量具有体液特异性的RNA标志物，进一步完善了编码区内单核苷酸多态性（coding single nucleotide polymorphim，cSNP）的可同时用于体液鉴定和个体识别的候选基因列表。

关键词:  , 法医物证学；体液鉴定；转录组测序；RNA；qPCR