片段长度差异等位基因特异性PCR——一种改良的SNP分型新方法

目的建立一种基于等位基因特异性PCR原理的改良SNP分型新方法:片段长度差异等位基因特异性PCR,并考察特异性引物的3'端第3位、第4位碱基错配对特异性延伸的影响。方法以SNP位点rs759117和rs760887为例,设计两条长度不同、3'末端分别与SNP两个等位基因碱基配对的上游引物,同时在两个等位基因特异性引物3'端第3或第4位碱基引入错配以增加特异性,下游为公用引物。PCR产物经聚丙烯酰胺凝胶电泳、银染显带后确定样本的基因型。结果不同SNP纯合子为长度不同的单一谱带,杂合子则为两条带,其结果与直接测序完全一致。两条特异性上游引物3'端第3或第4位碱基引入错配后非特异性延伸显著减少,且对PCR反应条件的严格性要求明显降低。结论片段长度差异等位基因特异性PCR是一种简单快速而有效的SNP分型新方法;两条特异性引物3'端第3、第4位碱基引入错配可使特异性显著增加     

基于等位基因特异性PCR原理建立的SNP分型新方法

目的建立一种新方法,对多个单核苷酸多态性(singlenucleotidepolymorphism,SNP)位点进行分型。方法基于等位基因特异性PCR原理,采用荧光标记复合扩增和毛细管电泳技术,根据PCR片段长度差异进行分型。选择SNP位点共11个,每个SNP位点设计两条长度不同、3’末端分别与SNP两个等位基因碱基配对的上游引物,同时为了增加特异性,在两条等位基因上游引物的3’末端第3或第4位碱基人为引入错配。在距离上游引物100～300bp范围内的合适位置,设计下游共用引物,并进行荧光标记。所有位点经过复合扩增后,PCR产物经ABIPrismTM310型遗传分析仪电泳分离,确定每个SNP的基因型。结果每个SNP位点纯合子为单一产物峰,杂合子则为长度不同的两个产物峰。不同的SNP位点扩增产物长度不同,根据产物长度和产物峰的数量进行SNP分型,一次完成11个SNP位点分型,其结果与直接测序完全一致。结论荧光标记复合扩增片段长度差异等位基因特异性PCR法是一种简单快速而有效的SNP分型新方法。     

ABO基因分型的等位基因特异性引物消耗法

目的建立一种新的ABO基因型分型的等位基因特异性引物消耗法(CASPA)。方法根据ABO基因碱基序列中的第261、297、803nt3处多态性位点设计6条特异性引物及1条公用引物,采用CASPA法鉴定146名中国汉族无关个体血液斑样品的ABO基因型。结果146名中国汉族无关个体血液斑样品中检出AAb、AB、AO1、BOv、O1Ov、AA、BB、O1O1、BO1等9种基因型,结果明确,其基因频率分布符合Hardy-Weinberg平衡。结论ABO基因型CASPA分型方法为ABO血型的鉴定提供了一个新的检测方法。     

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。     

D8S1179基因座等位基因丢失现象的研究

目的 探讨在进行STR分型时发生的等位基因“丢失”情况的原因。方法 分别采用Profiler Plus试剂盒和GenBank数据库设计的引物,对D8S1179基因座进行基因分型,并对丢失的等位基因进行测序分析。结果D8S1179基因座丢失的等位基因在第147位碱基出现G-A转换。在中国人群中,该位置出现碱基转换的频率是0.50×10-2(在2013个无关个体中观察到10例无关变异事件)。结论 第147位碱基转换正好位于Prfiler Plus试剂盒中D8S1179基因座的引物结合区域,导致扩增时等位基因丢失。     

用PCR技术检验MN基因型

MN抗原决定簇是由寡糖和多肽构成的唾液酸糖蛋白,寡糖和多肽在结构上存在差异。这些差异由1组基因控制的［1,2］。多肽部分的差异由第4号染色体上的1对等位基因（Gly－cophorinA,GPA）决定,编码区3个核苷酸的差异导致了肽链N末端第1位和第5位氨基酸差异,第1位氨基酸M型为丝氨酸（TC）,N型为亮氨酸（TTA）;第5位氨基酸M型为甘氨酸（GGT）,N型为谷氨酸（GAG）［3］。根据MN基因的基因座核着酸序列的差异设计出型特异性引物,可用PCR技术检验MN血型的基因型。本文参照Chrfield等［4］和Nakayashiki等［5］的方法建立了快速…     

ABO基因分型及其在法医学中的应用

为建立一种ABO血型系统基因分型方法，采用PCR-RFLP技术，成功地将ABO系统区分为AA，AO，AB，OO，BB，BO六种基因型。对240名中国汉族无关个体血样的ABO（基因型频率调查结果表明，6种基因型的频率分布为0．0125～0．3834，符合Hardy－Weinbeng遗传平衡法则（P＞0．1），其DP值为0．8161。家系分析表明，亲代a、b、o基因传递遵守孟德尔遗传规律。对法医学中常见的血痕、混合斑、骨组织及毛发根部等生物样品进行检测，均能准确判定ABO基因型，并可在实际案件鉴定中应用。     

错配引物诱导酶切技术检测GC多态性

目的探讨建立检测GC点突变rs7041的引物错配诱导酶切技术（mismatch primer-induced RFLP,MPIR）及应用价值。方法针对GC基因点突变（NCBI Reference SNP ID：rs7401）,设计错配引物进行PCR扩增,引物错配碱基结合GC点突变诱导XhoI酶切,产生GC-rs7041片断长度多态性,并调查183例温州汉族无关群体GC-rs7401多态性。结果引物错配诱导酶切技术对GC-rs7041亚型的3种基因型分型明确。温州地区汉族人群GC-rs7041 T/G基因频率分别为0.787和0.213,基因型频率分别为T/T0.685、T/G 0.284和G/G 0.071,Ho（0.284）、He（0.337）、PIC（0.279）、DP（0.502）、PE（0.140）,基因型分布符合Hardy-Weinberg平衡。结论成功建立引物错配诱导酶切技术检测GC-rs7041单核苷酸多态性,该位点多态性有实际应用价值。     

引物3'端第二个碱基SNP变异的长度多态性遗传标记检测

目的为了获得引物3'端存在SNP点突变的插入缺失遗传标记rs10644346所有等位基因片段。方法基于等位基因特异性PCR原理,设计一条共用上游引物,二条3’端倒数第二个位置特异性碱基的下游引物。运用该三条引物检测150个无关个体及10例亲子关系已确定的三联体,同时运用其中二条引物(共同上游引物和其中一条下游引物)扩增9例样本。结果三条引物扩增150个无关个体均有清晰扩增片段;10例三联体案例亲代与子代扩增片段均符合孟德尔遗传定律;二条引物扩增9例样本后发现特定片段丢失。结论本次研究设计的三条引物PCR,证明特异性碱基位置除了通常的3'末端,理想条件下3'端的其他位置(如倒数第二个位置)也可以成为有效选择,该三条引物设计方法为检测引物侧翼存在点突变的遗传标记提供了一种新的参考。     

偏执型精神分裂症患者GRIN1基因-855G/C与-1140G/A位点的遗传多态性

目的探讨GRIN1基因启动子区两个单核苷酸多态性位点-855 G/C、-1140 G/A遗传多态性与偏执型精神分裂症的相关性及法医学意义。方法采用PCR限制性片段长度多态性(restriction fragment length polymorphism,RFLP)结合PAGE法对中国北方汉族183例健康无关个体和172例偏执型精神分裂症患者GRIN1基因5′端的-855 G/C和-1140 G/A位点多态性进行检测,采用χ2检验人群中基因型分布是否符合Hardy-Weinberg平衡定律,并比较两组人群中基因型和等位基因频率分布的差异。结果两组群体基因型分布符合Hardy-Weinberg平衡定律。-855 G/C位点基因型分布在对照组女性和实验组女性间的差异具有统计学意义(P0.05),-1140 G/A位点基因型和等位基因频率分布在对照组和实验组间及两组女性间差异具有统计学意义(P0.05)。结论 GRIN1基因启动子区-1140 G/A位点单核苷酸多态性可能与精神分裂症存在相关性;精神分裂症发生的遗传学因素可能存在性别倾向,可为精神分裂症的司法鉴定提供参考。     

ABO genotyping by mutagenically separated polymerase chain reaction

ABO blood groups were determined by the mutagenically separated polymerase chain reaction (MS-PCR). The products from two sets of PCR reactions using the same program for the nucleotides at positions 261 and 703 from cDNA at the ABO locus were used to distinguish A, B and O alleles. Two forward mutagenic allele-specific primers of different lengths for the ABO polymorphic site were paired with the same reverse primer in each PCR reaction. The 216 bp fragment of the PCR products for the 261th nucleotide was A or B allele-specific and the 195 bp fragment was O allele-specific. The 126 bp fragment of the PCR products for the 703th nucleotide was B allele-specific and the 106 bp fragment was A or O allele-specific. The ABO genotypes were determined by the intersection of the predicted alleles from these two PCR reactions. The PCR products were obtained using 10 ng of DNA in 50 μL of PCR reaction mixture, and electrophoresed in 4% agarose gel. In this study, 265 ABO-phenotype known samples (A: 31, B: 48, AB: 6 and O: 180) in Chinese were used. The results of ABO genotypes were AA: 1, AO: 30, BB: 2, BO: 46, AB: 6 and OO: 180. These results were confirmed by the PCR-RFLP ABO genotyping method. This technique is a simple, rapid, and reliable method for ABO genotyping.     

A New Method for Human ABO Genotyping Using a Universal Reporter Primer System

Abstract: We developed a new method for forensic ABO genotyping based on a universal reporter primer (URP) system. This allows for the simultaneous detection of six single nucleotide polymorphism (SNP) sites in the ABO gene (nucleotide positions 261, 297, 526, 703, 796, and 803). This URP system provides obvious peaks, ranging from 82 to 151 bp in length. ABO genotypes were classified and successfully genotyped by our method, including minor alleles that may cause a discrepancy between the genetic data and serological phenotypes. Full profiles were identified using as little as 0.1 ng (0.05 ng/reaction) of standard K562 and 9947A DNA. Moreover, the success rate of genotyping from a URP system was much higher than that from a conventional primer extension method in degraded DNA. This method enables simple and rapid detection of multiple SNP sites on human ABO genes and is highly specific and sensitive when using limited and degraded DNA.     

One method of collecting fallen off epithelial cell

In this paper, the comparative analysis of ABO genotyping and serological typing was conducted in 360 unrelated blood samples from northern Chinese Han population using genotyping method and serological typing method, respectively. The results of ABO genotyping were obtained by Goldeneye 16BT STR plus ABO kit. The ABO serological types were determined by the antigen–antibody agglutination test. The ABO types were confirmed by the two methods and no contradiction types were found; two more types were obtained using the ABO genotyping method and the discrimination power was further improved; the information of ABO genotyping and 15 STRs could be obtained at the same time using the Goldeneye 16BT STR plus ABO kit.     

Rapid direct PCR for ABO blood typing

Many different molecular typing methods have been reported to complement routine serological ABO blood typing in forensics. However, these ABO genotyping methods are often time-consuming and call for an initial DNA isolation step that requires the use of expensive kits or reagents. We report here a rapid direct ABO genotyping method that eliminates the need for DNA extraction from fresh blood, hair, and body fluid stains before PCR. Using a fast PCR instrument and an optimized polymerase, the genotyping method-which employs a multiplex allele-specific primer set for the simultaneous detection of three single-nucleotide polymorphism (SNP) sites (nucleotides 261, 526, and 803)-identifies A, B, O01/O02, O03, and cis-AB01 alleles in around 70 min from sample collection to electropherogram. Not only will this ABO genotyping method be efficiently used in forensic practice for rapid screening of samples before full-blown multilocus short tandem repeat profiling, but it will also demonstrate an example of rapid direct genotyping of SNPs that offers the advantages of time- and cost-efficiency, convenience, and reduced contamination during DNA analysis.     

A novel method for ABO genotyping using a DNA chip

ABO genotyping is often performed to identify the blood type of decomposed samples, which is difficult to be determined by a serological test. In this study, we developed a simple method for ABO genotyping using a DNA chip. In this method, polymerase chain reaction-amplified and fluorescent-labeled fragments in the ABO gene and primate-specific D17Z1 were hybridized with DNA probes on a chip designed to detect single nucleotide polymorphisms (SNPs) in the ABO gene and part of the D17Z1 sequence. Using blood samples from 42 volunteers and 10 animal species, we investigated whether the chip could be used to detect SNPs in the ABO gene and the D17Z1 sequence. This method was then applied to various forensic samples, and it was confirmed that this method was suitable for the simultaneous analyses of ABO genotyping and species identification. This method fulfills the recent need for the development of rapid and convenient methods for criminal investigations.     

运用二重PCR和DNA芯片技术检测ABO基因型

目的以玻片为载体,用寡核苷酸探针杂交技术检测ABO基因型。方法根据ABO基因座外显子6和外显子7的3个SNP点的序列分布特征设计4条寡核苷酸探针,制成分型芯片。将待测样品DNA用末端标记了Cy5的引物进行二重PCR扩增,产物与芯片上的探针进行杂交,根据杂交产生的荧光信号确定样品的ABO基因型。结果利用ABO芯片,可对血斑、毛发等微量检材进行ABO基因型检测。对115名汉族无关个体的调查表明,ABO基因型的分布符合Hardy-Weinberg平衡,等位基因杂合度观察值和期望值分别为0.591、0.616,多态信息含量为0.544,二联体和三联体非父排除率分别为0.188、0.334,个体识别能力为0.777。结论通过DNA芯片检测ABO基因型的技术适用于法医学样本,可满足高通量的检测需求。     

单管实时PCR快速检验ABO基因型

目的建立快捷特异的ABO基因分型检测方法。方法根据ABO基因结构特点,设计特异性引物和四色双链探针,采用单管实时PCR方法检测ABO基因,结果与传统免疫学方法相对比。结果该方法可检出常见的3个等位基因,区分常见的6种基因型,全部检测过程可在100min内完成。110例中国人的随机个体定型结果与传统免疫学方法一致。结论实时PCR法进行ABO基因分型,简便快捷,灵敏度高,可以有效地为侦查破案服务。     

Alleles responsible for ABO phenotype-genotype discrepancy and alleles in individuals with a weak expression of A or B antigens

ABO types obtained from evidentiary samples have been used effectively to obtain the initial information leading to the apprehension of culprits in Japanese criminal investigations. A simple ABO genotyping method using multiplex sequence-specific PCR and capillary electrophoresis was developed as a supplement to serological ABO typing. Limitations in predicting a phenotype based on genotype were evaluated using 1134 randomly selected Japanese peripheral blood samples. A concordance rate of 99.82% (1132/1134 samples) was found between genotypes and phenotypes defined as Groups A, B, AB, and O. Sequencing analysis revealed that one discrepant sample contained an O allele having a previously unreported point mutation at the primer binding site in exon 6, and another discrepant sample contained an O allele lacking the guanine deletion at nt 261 (the O301 allele). Therefore, the existence of such alleles must be given some consideration when predicting phenotype based on genotype.