二代测序Y-STR序列多态性之“折叠序列”变异助力侦破21年冷案  

‘Folded Sequence’Variation in a Y-STR Locus Revealed by Nextgeneration Sequencing Helped in Solving a 21-year-long Cold Case

作　　者：张驰 康克莱 李蓓 孙博雅 缪磊 焦瑞莲 孟洋 赵杰 贺琳 季安全 王乐 ZHANG Chi;KANG Kelai;LI Bei;SUN Boya;MIAO Lei;JIAO Ruilian;MENG Yang;ZHAO Jie;HE Lin;JI Anquan;WANG Le(Institute of Forensic Science,Ministry of Public Security,Key Laboratory of Forensic Genetics of Ministry of Public Security,Beijing 100038,China;Xingtai Public Security Bureau,Xingtai 054001,Hebei,China)

机构地区：[1]公安部鉴定中心,法医遗传学公安部重点实验室,北京100038 [2]邢台市公安局,河北邢台054001

出　　处：《刑事技术》2024年第6期639-644,共6页Forensic Science and Technology

基　　金：国家重点研发计划(2017YFC0803503)。

摘　　要：基于传统毛细管电泳技术的STR检验仅关注长度多态性,不能报告STR等长等位基因间的SNP、InDel等序列差异信息。二代测序技术可以检出更丰富的STR序列多态性,既包括重复区的重复序列和非重复间隔序列信息,也包括侧翼区的序列信息,支撑更精准的比对分析。本文报道一起长达21年未破的入室杀人案,用传统Y-STR检测方法得到了38个Y-STR基因座长度多态性分型。通过二代测序方法,使用STRSeqTyperY68试剂盒检验1份现场物证和8份比对样本,均得到了全部67个Y-STR基因座序列多态性分型。其中DYS448基因座N_(42)“折叠序列”中的一个单碱基变异为案件指明方向,提供了关键的技术支撑。本文进一步探讨了DYS448基因座N_(42)“折叠序列”在不同人群中的序列变异情况,以及STRSeqTyperY68试剂盒中具有“折叠序列”的基因座详细信息,为相关研究和案件应用提供参考。STR genotyping based on the traditional capillary electrophoresis technology focuses on length polymorphisms of the markers.Sequence differences among STR isometric alleles,such as SNPs and InDels,cannot be reported.Nextgeneration sequencing can report abundant sequence polymorphism information of STRs,including the repetitive sequence and non-repetitive interval sequence information in STR repeat regions,as well as sequence information in flanking regions,supporting forensic applications.This article reported a 21-year-long indoor homicide case.Genotypes for 38 Y-STRs were obtained by the traditional Y-STR detection method.Y-STR sequence information was reported by using the STRSeqTyperY68 kit and next-generation sequencing technology.The STRSeqTyperY68 kit genotypes fifty-two single-copy Y-STR loci,six two-copy Y-STRs,one three-copy Y-STR,and one sex determinant locus in a single reaction tube using the MiSeq FGx sequencing platform.Full sequence-based genotypes of 67 Y-STR markers were determined for one evidence collected from crime scene and eight reference samples.After comparing the 67 Y-STR genotyping result of the crime scene evidence with the eight reference samples,we found that the length-based genotypes at DYS448 were 20 among for all these nine samples.Their repeat structures were also consistent,which were the combination of 11[AGAGAT]repeat units and 9[AGAGAT]repeat units with a non-repetitive sequence of 42 nucleotides(N_(42))in the middle.However,the difference lied in the 32nd base of the“folded sequence”N_(42)of DYS448:scene evidence and sample 1 were C,while the other seven reference samples were T.Based on a single base substitution in the N_(42)‘folded sequence’of the DYS448 locus,the case was directed and key technological support was provided.This article further explored sequence variations in the N_(42)‘folded sequence’of DYS448 in different populations,as well as detailed information on loci with‘folded sequence’in the STRSeqTyperY68 kit,providing reference for related

关 键 词：法医遗传学 二代测序 Y-STR 序列多态性 冷案 

分 类 号：DF795.2[医药卫生—法医学]