构建精液特异的DNA甲基化-SNP分型体系并试测精液来源

Constructing Semen-specifi c Methylated-DNA-orienting SNP Typing System to Tentatively Identify Human Semen Origin

目的初步构建DNA甲基化联合SNP分型体系,探索其用于精液来源鉴定的价值。方法首先通过分析甲基化芯片数据筛选出精液特异性的甲基化位点,通过软件设计出各位点特异性引物,再利用SNaPshot技术对各位点相邻的SNP进行检测,尝试鉴定精液来源。结果本实验成功构建了以精液作为鉴定对象的四位点甲基化-SNP分型复合检测体系,其对62份随机取样的中国汉族体液样本的鉴定结果表明其特异性良好,可准确区分出44份精液或精斑样本与其他三类共18份体液样本。且其灵敏度佳,在转化DNA量为0.5ng时仍可获得完整分型。在混合斑实验中,当精液与阴道分泌液体积比例为1∶40时,该复合体系仍能获得精液完整的分型图谱。结论该四位点复合分型体系在精液鉴定中具有重要价值,证明了DNA甲基化联合SNP分型体系用于体液鉴定的可行性。

Objective To trial-construct the methylated-DNA-orienting multiplex SNP typing system and explore its value in identifying human semen samples.Methods The human semen-specific methylation sites were selected through analyzing the data from DNA methylation microarray.Specific primers of the selected sites were afterwards designed with several suites of pertinent software.SNaPshot was used to detect the neighboring single nucleotide polymorphisms(SNPs),thereby helping make the human semen origin able to be deduced.Results The 4-plex DNA methylated-locus-orienting SNP typing system for identifying human semen was successfully constructed,leading that 62 body fluids randomly collected from Chinese Hanethnic individuals were showed of desirable human semen-specificity.The system has therefore accurately differentiated 44 human semen samples from the other 18 samples of three kinds of non-semen origin.Meanwhile,Unambiguous profiles can be even exposed when the bisulfite-converted DNA was input of only 0.5ng.Satisfactory typing profiles were indeed presented out of the mixed stains that were resulted from mixing human semen and vaginal fluid in volume ratio of 1:40.Conclusions This 4-plex SNP typing system is of great value in identifying human semen.Besides,it proves that the DNA methylatedlocus-orienting multiplex SNP typing system is practical for identifying human body fluids.