刑事技术2023，Vol.48Issue(6)：584-592,9.DOI:10.16467/j.1008-3650.2023.0013
piRNAs在法医学体液鉴定中的能力评估
Evaluation of piRNAs Application in Forensic Body Fluid Identification
摘要
Abstract
Based on a large number of forensic and related medical literature and bioinformatics databases,the purpose of this study is to explore the expression differences of non-coding Piwi-interacting RNA(piRNA)molecules in common forensic body fluids,evaluate the body fluid differentiation ability of target molecules by statistical analysis,and establish a suitable model of identification method,so as to provide a method supplement for the identification of common body fluids(spots)in forensic genetics.In this study,we collected 120 human common body fluid samples in forensic genetics(including peripheral blood,menstrual blood,semen,saliva and vaginal secretion),and the expression of target piRNA molecules in five kinds of body fluids was detected by real-time fluorescent quantitative PCR method.To determine the applicable internal reference genes,the stability of the three internal parameters in five kinds of body fluids was evaluated by Genorm,NormFinder,BestKeeper software and △Ct four methods.The difference of relative expression △Cq of each marker in different body fluids was analyzed,and the marker molecules which can be used to distinguish body fluids were screened.At the same time,aiming at the difficult problem of distinguishing between saliva and vaginal secretion in forensic application,three piRNA molecules were identified and combined to establish a support vector machine(SVM)classification model to identify saliva and vaginal secretion.In addition,the stability of these small molecules was evaluated by detecting the relative expression of piRNAs in simulated case samples dried at room temperature for 1 month,6 months,12 months and ultraviolet irradiation for 12 hours and 48 hours,respectively.Finally,in this study,nine marker molecules were screened for body fluids identification,which were piR-33043,piR-33151,piR-57125,piR-31662,piR-31068,piR-31925,piR-43771,piR-43773,piR-55521,and the piR-33151,piR-31662 and piR-31925 three piRNA molecules combination was established as a SVM classification model to effectively distinguish saliva and vaginal secretion with an accuracy of 100％.These three piRNA molecules could still be detected in samples dried indoors for 12 months or UV irradiation for 48 hours.The results of this study show that there were significant differences in the relative expression of piRNA molecules in different body fluids.PiRNA molecules have the ability to identify common types of body fluids in forensic genetics,and the established classification model can effectively and accurately distinguish saliva and vaginal secretion,which has high application potential.关键词
法医遗传学/piRNA/体液鉴定/支持向量机分类模型Key words
forensic genetics/piRNA/body fluid identification/support vector machine classification model分类
政治法律引用本文复制引用
李文,胡胜,季安全,孙启凡,赵一霞..piRNAs在法医学体液鉴定中的能力评估[J].刑事技术,2023,48(6):584-592,9.基金项目
公安部科技强警基础工作专项(2020GABJC15) （2020GABJC15）
