法医学杂志

法医学杂志 ›› 2020, Vol. 36 ›› Issue (3): 316-325.DOI: 10.12116/j.issn.1004-5619.2020.03.005

• 论著 • 上一篇    下一篇

SNP-STR遗传标记复合扩增体系的构建及法医学应用

王秋月， 杨以文， 曹悦岩， 朱强， 黄雨果， 胡渝涵， 周怡君， 李茜， 尉艺凡， 舒潘寅， 王玉芳， 张霁   

  1. 四川大学华西基础医学与法医学院，四川 成都 610041
  • 发布日期:2020-06-25 出版日期:2020-06-28
  • 通讯作者: 张霁，男，教授，博士研究生导师，主要从事法医遗传学研究；E-mail：zhangj@scu.edu.cn
  • 作者简介:王秋月（1993—），女，硕士研究生，主要从事法医遗传学研究；E-mail：1312756927@qq.com
  • 基金资助:
    国家自然科学基金资助项目（81571861，81630054）

Construction of SNP-STR Multiplex Amplification System with Genetic Markers and Its Forensic Application

WANG Qiu-yue, YANG Yi-wen, CAO Yue-yan, ZHU Qiang, HUANG Yu-guo, HU Yu-han, ZHOU Yi-jun, LI Xi, WEI Yi-fan, SHU Pan-yin, WANG Yu-fang, ZHANG Ji   

  1. West China School of Basic Medical Sciences & Forensic Medicine, Sichuan University, Chengdu 610041, China
  • Online:2020-06-25 Published:2020-06-28

RichHTML

16

PDF (PC)

706

摘要： 目的 筛选并构建与目前STR数据库兼容的SNP-STR遗传标记复合扩增体系，调查其在四川汉族群体中的遗传多态性，并探讨其在混合DNA样本分析中的应用价值。 方法 以现有商业试剂盒中使用的STR遗传标记为基础，筛选与STR遗传标记相邻的SNP位点并组成SNP-STR遗传标记。运用SNP等位基因设计特异性引物，构建基于等位基因特异性扩增的SNP-STR遗传标记复合扩增体系。调查该体系在四川汉族群体的遗传多态性，并评价不同位点数目的体系对两个体混合DNA样本的检测效能。 结果 筛选并构建了由13个SNP-STR遗传标记构成的等位基因特异性复合扩增体系。在四川汉族群体中，各位点杂合度为0.76~0.88，累积个体识别率达0.999 999 999 999 999 968。在对两个体混合DNA的分析中：单位点扩增时，混合样本的混合比例达到1 000∶1时依然可以检测到少量成分所特有的分型；多位点复合扩增时，混合比例最大可达500∶1；随着体系中位点数量的增加，对混合DNA中少量成分的检测效能降低。 结论 SNP-STR遗传标记较STR具有更高的多态性，其构成的复合扩增体系对混合样本的分析效能优于传统的STR复合扩增体系。

关键词: 法医遗传学；多态性, 单核苷酸；短串联重复；等位基因特异性聚合酶链反应；混合DNA

Abstract: Objective To select and develop a SNP-STR multiplex amplification system with genetic markers compatible with current STR databases. To understand its genetic polymorphisms in Sichuan Han population and its application value in DNA mixture analysis. Methods Based on the STR genetic markers in commercial kits, SNPs adjacent to these STR markers were selected to be SNP-STR genetic markers. A SNP-STR multiplex amplification system with genetic markers based on allele-specific amplification was constructed using allele-specific amplification primers. The genetic polymorphism of the system in the Sichuan Han population was investigated and the efficiency of systems with different numbers of loci to detect the two individual DNA mixture samples was evaluated. Results An allele-specific multiplex amplification system constituted of 13 SNP-STR genetic markers was selected and constructed. In Sichuan Han population, the heterozygosity of each locus ranged from 0.76 to 0.88, and the combined discrimination power reached 0.999 999 999 999 999 968. In the analysis of the two individual DNA mixture samples： for single-locus amplification, the genotype of the minor components can still be detected when the mixture ratio reaches 1 000∶1; for multiple loci multiplex amplification, the maximum mixture ratio can reach 500∶1. As the number of loci in the system increased, the detection efficiency of the minor components in the DNA mixture decreased. Conclusion SNP-STR genetic markers have a higher polymorphism than STR. The multiplex amplification system made of SNP-STR genetic markers has a better analysis efficiency for mixed samples than traditional STR multiplex amplification system.

Key words: forensic genetics, polymorphism, single nucleotide, short tandem repeat, allele specific-polymerase chain reaction, mixed DNA