线粒体DNA nt8584、nt8701单核苷酸多态性研究

目的建立一种快速、准确的线粒体DNA单核苷酸多态性位点检测方法。方法收集62份无关个体血液样本,应用荧光定量PCR技术研究线粒体DNA nt8584、nt8701位点在中国汉族人群中的多态性。结果 nt8584位点检测到10例nt8584A、52例nt8584G,nt8584A/G变异频率为16∶84;nt8701位点检测到27例nt8701A、35例nt8701G,nt8701A/G变异频率为44∶56。结论所建立的荧光定量PCR方法分型准确、耗时短,适用于法医DNA检验。     

AS-PCR技术检测20个mtDNA SNP位点及单倍型频率

目的基于等位基因特异性PCR(allele-specific PCR,AS-PCR)技术,建立一种三色荧光标记复合扩增检测线粒体DNA(mtDNA)SNP的方法。方法基于AS-PCR原理,选择20个mtDNA编码区SNP位点,分为两组,分别标记FAM和HEX荧光,每个位点设计具有长度差异的两条上游(下游)等位基因特异性引物以及一条下游(上游)通用引物。结合AS-PCR技术和毛细管电泳,检测200份无关个体血样。各位点随机选取至少3个样本进行直接测序验证,并进行单倍型频率调查。结果 200份血样均得到清晰分型,各位点的检测结果与直接测序结果完全一致。10μL体系下,DNA最低检测浓度为0.2pg,当模板量为0.5~5 pg时能得到较为理想的分型图谱。在200名无关个体中,共分出15种单倍型,单倍型多样性为0.906 0。结论 AS-PCR技术是一种简单、快速且有效的mtDNA SNP分型方法,适用于法庭科学检验的需求。     

3个miniSTR基因座荧光标记复合扩增体系的建立及应用

目的建立扩增片段小于115 bp,包括D1S1676、D6S1274和D17S1299 3个非CODIS系统的miniSTR基因座复合扩增系统,用于高度降解DNA样本的基因分型。方法采用不同荧光染料标记引物,通过PCR扩增,利用310遗传分析仪对100份成都汉族健康无关个体血样以及2份高度降解检材进行检测。结果荧光标记复合扩增D1S1676、D6S1274和D17S1299 3个miniSTR基因座,每个基因座均获得了清晰的基因型分型结果。100份样本,3个miniSTR基因座分别检出个9、9、7个等位基因和27、23、18种基因型,基因型分布均符合Hardy-Weinberg平衡。3个基因座在成都汉族人群的累积非父排除率、累积个体识别能力分别为0.9991和0.9160。结论本系统可以应用于个体识别和亲权鉴定,为DNA高度降解样本分型提供了新的方法。     

TaqMan探针技术用于X-SNP位点的分型

目的建立一种基于TaqMan探针技术的快速、准确且经济的实时荧光PCR方法,用于检测X染色体上的单核苷酸多态性(single nucleotide polymorphism,SNP)。方法选择X染色体上的13个SNP位点(X-SNP),针对每个位点分别设计1对PCR引物和TaqMan探针,进行实时荧光PCR扩增,对X-SNP位点进行分型。结果13个位点均符合Hardy-Weinberg平衡;多态信息含量分布为0.3497～0.3750,杂合度为0.4537～0.5021。建立的方法能够用于X-SNP位点的基因分型,检测结果与DNA测序结果完全一致。结论基于TaqMan探针技术的等位基因特异的实时荧光PCR方法灵敏、简单、快速,可实现对X-SNP位点的分型检测;所选择的13个X-SNP位点具有高信息量,在法医遗传学中具有潜在的应用价值。     

批量陈旧血样DNA的自动化检验

目的建立批量陈旧血样DNA自动化提取检验的方法。方法采用普通磁珠法和本文建立的磁珠法经TECAN Freedom EVO150—8型自动化工作站分别提取540份陈旧血样模板DNA,采用Sinofiler^TM试剂盒进行荧光标记复合扩增。结果采用普通磁珠法和本文所建DNA提取方法,在540份样本中获得全部基因座STR分型的样本分别为217份和488份,检验成功率分别为40．2％和90．3％。结论本文所建方法可显著提高大批量陈旧血样自动化检验成功率。     

PCR-STR分型技术在尿样DNA分型中的应用

目的　对尿样的DNA分型进行研究。　方法　 10份尿样随机收集于无关个体 ,同时采集血液样本做DNA分型对照 ,用PCR -STR分型技术对尿样DNA进行FIBRA和D18S5 35基因座分型。　结果　 10份尿样 10ml、1ml及 0 .2ml体积均获得准确的分型结果 ,且与同一个体的血样DNA分型结果完全相同 ;室温储存 4天及 4℃保存 4周的尿样均分型成功。　结论PCR -STR分型技术对尿样DNA分型是一种有效的方法 ,在尿样的个人识别中具有极高的实用价值。     

PCR-RFLP在mtDNA多态性分析中的应用

目的探讨PCR-RFLP法在mtDNA多态性分析中的应用价值。方法应用限制酶RsaI和MnlI消化mtDNA D-LOOP区（HVI16106～16297）PCR扩增产物,聚丙烯凝胶电泳进行RFLP分型,对不同PCR-RFLP分型扩增产物进行测序,并对150例辽宁汉族随机个体及30例真三联家系血样进行检验。结果在150例随机个体中,RsaI和MnlI酶切分别发现3和8种表型,DNA测序结果和PAGE分型结果一致,GD值分别为0.107,0.670。联合两种酶切,发现12种表型,GD值为0.708。在30个家系中,母子的RFLP带型完全相同。结论 PCR-RFLP法适合在基层实验室mtDNA分析中应用。     

氨基比林血痕预试验处理血痕后样本的DNA定量

目的：探讨氨基比林血痕预试验处理血痕后样本DNA含量的变化及对STR分型检测的影响。方法10名健康无关个体EDTA抗凝血液制成滤纸血痕,氨基比林血痕预试验检测,按试验后血样干燥保存时间分30 min、1 h、3 h、6 h、12 h、24 h共6个实验组,并采用磁珠法、QIAcube DNA纯化法、Chelex-100法三种方法提取样本DNA,应用荧光定量PCR检测样本DNA含量,PCR-STR荧光技术进行STR分型。结果提取方法相同时,氨基比林血痕预试验后血样随干燥保存时间的延长,样本DNA含量呈逐渐降低的趋势。保存时间相同时,不同DNA提取方法间,样本DNA含量差异也有统计学意义。90.56%样本均可获得16个STR基因座明确分型。结论氨基比林血痕预试验对血痕样本DNA有损伤,24 h内多可获有效STR分型。磁珠法提取样本DNA进行STR分型,效果最好。     

PCR-STR分型技术在尿样DNA分型中的应用

目的：对尿样的DNA分型进行研究。方法：10份尿样随机收集于无关个体,同时采集血液样本做DNA分型对照,用PCR－STD分型技术对尿样DNA进行FIBRA和D18S535基因座分型。结果：10份尿样10ml、1ml及0．2ml体积均获得准确的分型结果,且与同一个体的血样DNA分型结果完全相同;室温储存4天及4℃及4周的尿样均分型成功。结论：PCR－STR分型技术对尿样DNA分型是一种有效的方法,在尿样的个人识别中具有极高的实用价值。     

一种简便的DNA提取方法在动物毛发检验中的应用

目的建立一种简便的DNA提取方法,用于动物毛干的DNA抽提。方法利用PCR缓冲液及蛋白酶K在PCR仪上对毛发进行消化,以此DNA为模板,扩增mtDNA 12S rRNA基因的部分片段并进行序列测定,测序结果在GenBank上进行BLAST搜索,再利用DNAMAN软件进行同源性分析。结果利用这种新DNA抽提法能从无毛囊毛发中获得后续PCR扩增所需的线粒体DNA。结论该法在无毛囊毛发样本鉴定中具有较高的应用价值。     

Real-time PCR designs to estimate nuclear and mitochondrial DNA copy number in forensic and ancient DNA studies

We explore different designs to estimate both nuclear and mitochondrial human DNA (mtDNA) content based on the detection of the 5' nuclease activity of the Taq DNA polymerase using fluorogenic probes and a real-time quantitative PCR detection system. Human mtDNA quantification was accomplished by monitoring the real-time progress of the PCR-amplification of two different fragment sizes (113 and 287 bp) within the hypervariable region I (HV1) of the mtDNA control region, using two fluorogenic probes to specifically determine the mtDNA copy of each fragment size category. This mtDNA real-time PCR design has been used to assess the mtDNA preservation (copy number and degradation state) of DNA samples retrieved from 500 to 1500 years old human remains that showed low copy number and highly degraded mtDNA. The quantification of nuclear DNA was achieved by real-time PCR of a segment of the X-Y homologous amelogenin (AMG) gene that allowed the simultaneous estimation of a Y-specific fragment (AMGY: 112 bp) and a X-specific fragment (AMGX: 106 bp) making possible not only haploid or diploid DNA quantitation but also sex determination. The AMG real-time PCR design has been used to quantify a set of 57 DNA samples from 4-5 years old forensic bone remains with improved sensitivity compared with the slot-blot hybridization method. The potential utility of this technology to improve the quality of some PCR-based forensic and ancient DNA studies (microsatellite typing and mtDNA sequencing) is discussed.     

线粒体高变区多聚C-stretch序列长度多态性

目的研究线粒体高变区多聚C-stretch序列长度多态性,并探讨其在法医学个体识别中的价值。方法针对线粒体高变区nt16180及nt310两个位点采用文献报道引物,应用直接测序技术研究其等位基因分布及频率。结果两对引物扩增长度分别为807bp和962bp,nt16180位点检测到7种基因型,其中AAAACCCCCTCCCC基因型占87.72%,AAAACCCCCCCCCCCCC基因型在汉族人群中首次报道;nt310检测到7种基因型,其中CCCCCCCCTCCCCCC基因型占60.53%;联合两个位点共检测出15种单倍型,GD值为0.6309,其中AAAACCCCCTCCCC-CCCCCCCCTCCCCCC检测出66条,达到57.89%。结论为线粒体控制区DNA在法医学领域中的应用提供基础数据,证实了线粒体nt16180位点和nt310位点单倍型在线粒体DNA鉴定中有较好的应用价值。     

16个线粒体DNASNP复合检测体系的建立

目的建立一种复合检测线粒体DNA（mtDNA）单核苷酸多态性（SNP）分型的方法。方法通过设计等位基因特异性引物并结合毛细管电泳分型技术平台,建立包含16个mtDNASNP位点的复合扩增检测体系。对50名汉族无关个体血样进行mtDNASNP检测,并通过直接测序法对其分型结果进行验证。结果50个样本经本检测体系复合扩增后,均得到清晰的SNP分型结果,当模板量在0．5～10pg时能得到较理想的分型图谱。样本的复合检测结果与直接测序法结果完全一致。结论建立的复合检测体系检测mtDNASNP方法灵敏度高、操作简便、分型准确,为针对mtDNA进行简便、有效的中高通量多态性分型提供了一种新方法。     

HLA—A基因座分步PCR—SSP分型研究

目的使HLA基因分型能应用于法医常见检材的个人识别。方法 建立检测HLA—A基因座的分步PCR—SSP方法。先用一对HLA—A基因座特异的引物作第一次扩增,以所得产物为模板,分别用对HLA—A30、A31、A33特异的3对引物作第二次扩增,二次扩增的产物经电泳判型。结果 1130例血清分型为HLA—A30、A31、A33的血痕,其PCR—SSP分型和血清分型的不符合率为29％;室温保存2年的精斑、唾液斑,保存18年的血痕第一次扩增均获得满意的结果。结论法医亲子鉴定和个人识别宜用基因分型替代血清分型。HLA—A基因座分步PCR—SSP基因分型适用于法医检材。     

Results from the NIST 2004 DNA Quantitation Study

For optimal DNA short tandem repeat (STR) typing results, the DNA concentration ([DNA]) of the sample must be accurately determined prior to the polymerase chain reaction (PCR) amplification step in the typing process. In early 2004, the National Institute of Standards and Technology (NIST) conducted an interlaboratory study to help assess the accuracy of DNA quantitation in forensic DNA laboratories. This study was designed with four primary purposes: (1) to examine concentration effects and to probe performance at the lower DNA concentration levels that are frequently seen in forensic casework; (2) to examine consistency with various methodologies across multiple laboratories; (3) to examine single versus multiple source samples; and (4) to study DNA stability over time and through shipping in two types of storage tubes. Eight DNA samples of [DNA] from 0.05 ng/microL to 1.5 ng/microL were distributed. A total of 287 independent data sets were returned from 80 participants. Results were reported for 19 different DNA quantitation methodologies. Approximately 65% of the data were obtained using traditional slot blot hybridization methods; 21% were obtained using newly available quantitative real-time PCR (Q-PCR) techniques. Information from this interlaboratory study is guiding development of a future NIST Standard Reference Material for Human DNA Quantitation, SRM 2372.     

用PCR-DGGE技术检测人外周血mtDNA HVⅠ单倍型及异质性

目的建立简单、有效的m tDNA单倍型检测及异质性筛查技术,并获取其相应的汉族人群频率分布。方法用PCR-DGGE技术对200例武汉汉族无关个体外周血m tDNA HVⅠ15997~16174nt和16208~16401nt区域进行分型检测。结果200例汉族无关个体中,15997~16174nt和16208~16401nt区域分别检出20种和22种单倍型,其单倍型多样性(HD值)分别为0.8159和0.8844;m tDNA HVⅠ组合单倍型共90种,其HD值达0.9803。两区域分别有4名和2名个体观察到异质性,其发生率为3%。结论PCR-DGGE是一种简单、灵敏、高效的m tDNA多态性及异质性检测技术,可应用于法医学实践。     

中国朝鲜族线粒体DNA编码区序列多态性

目的调查中国朝鲜族群体线粒体DNA（mtDNA）编码区内5个部位 3954～4506nt、5218～5974nt、7942～871Int、10296～10653nt 及14496～14867nt的序列多态性。方法采用PCR产物直接测序方法,对212名中国朝鲜族（吉林省延边地区）无关个体进行序列多态性变化和单倍型分布调查。结果在212名无关个体中,共分出148种单倍型。遗传变异度为0．9931,耦合概率为0．0116。测序结果与Anderson标准序列比较,共检测出109个变异位点,其中79个已收录于MITOMAP。结论mtDNA编码区多态性联合应用可以提高mtDNA的个体识别能力。町为相关遗传学研究提供基础数据资料。     

Typing the 1.1 kb control region of human mitochondrial DNA in Japanese individuals

This study presents a reliable method that uses high-fidelity long-range PCR and optimized primers to assess polymorphism and to genotype human mitochondrial DNA (mtDNA). This method was used to analyze polymorphic sites in the human mtDNA control region, including hypervariable regions I, II, and III (HVI, HVII, and HVIII), from 124 unrelated Japanese individuals. In HVI, HVII, and HVIII, 80, 37, and 14 polymorphic sites were identified, respectively, excluding those in the homopolymeric cytosine stretch (C-stretch) regions. The region between HVI and HVII also contained 15 polymorphic sites. On the other hand, C-stretch length heteroplasmy in HVI or HVII was observed in 66 of 124 Japanese individuals (53%), which is much higher than in Caucasian populations. The variants in the C-stretch regions were characterized by counting the number of heteroplasmic peaks split from the single peak in homoplasmic sequences (i.e., 16244G and 16255G in HVI and 285G in HVII). Including the C-stretch length heteroplasmy, the 124 Japanese mtDNA samples were classified into 116 distinct haplotypes. The random match probability and the genetic diversity were estimated to be 0.95% and 0.998581, respectively, indicating that the method presented here has higher discrimination than the conventional method for mtDNA typing using HVI and HVII. [Correction added after publication 30 January 2007: in the preceding sentence random match probability and genetic diversity estimates were corrected from 0.95 and 0.998581%, respectively, to 0.95% and 0.998581, respectively.] The haplogroups and their frequencies observed in this study (i.e., D4; 13.7%, M7a1; 11.3%, D4a; 9.7% and M7b2; 8.9%) were similar to those observed in other studies of Japanese mtDNA polymorphism. The method described here is suitable for forensic applications, as shown by successful analysis of tissues from highly putrefied remains of an infant, which allowed maternal relationship to be determined via mtDNA haplotyping.     

Quantification of human mitochondrial DNA using synthesized DNA standards

Successful mitochondrial DNA (mtDNA) forensic analysis depends on sufficient quantity and quality of mtDNA. A real-time quantitative PCR assay was developed to assess such characteristics in a DNA sample, which utilizes a duplex, synthetic DNA to ensure optimal quality assurance and quality control. The assay's 105-base pair target sequence facilitates amplification of degraded DNA and is minimally homologous to nonhuman mtDNA. The primers and probe hybridize to a region that has relatively few sequence polymorphisms. The assay can also identify the presence of PCR inhibitors and thus indicate the need for sample repurification. The results show that the assay provides information down to 10 copies and provides a dynamic range spanning seven orders of magnitude. Additional experiments demonstrated that as few as 300 mtDNA copies resulted in successful hypervariable region amplification, information that permits sample conservation and optimized downstream PCR testing. The assay described is rapid, reliable, and robust.