D3S1754、D18S535基因座在中国北方汉族的多态性分析

目的 了解D3S1754、D18S535基因座多态性在中国北方人群中的分布特点及其应用价值。方法 使用PCR、聚丙烯酰胺垂直板电泳及银染的方法。结果D3S1754基因座检出9个等位基因（n=184）,D185535基因座检出8个等位基因（n=201）,两个位点的等位基因频率在群体中的分布符合Hardy-Weinberg平衡（P>0.05）,它们的杂合率（He）分别为0.706和0.807,个人识别机率（DP）分别是0.859和0.934,非父排除率（EPP）分别为0.464和0.629。结论 D3S1754、D18S535两个遗传标记的个人识别率高、非父排除能力较强且能稳定遗传,具有较高的应用价值。     

Screening Biological Stains with qPCR versus Lateral Flow Immunochromatographic Test Strips: A Quantitative Comparison using Analytical Figures of Merit

Biological fluid identification is an important facet of evidence examination in forensic laboratories worldwide. While identifying bodily fluids may provide insight into which downstream DNA methods to employ, these screening techniques consume a vital portion of the available evidence, are usually qualitative, and rely on visual interpretation. In contrast, qPCR yields information regarding the amount and proportion of amplifiable genetic material. In this study, dilution series of either semen or male saliva were prepared in either buffer or female blood. The samples were subjected to both lateral flow immunochromatographic test strips and qPCR analysis. Analytical figures of merit—including sensitivity, minimum distinguishable signal (MDS) and limit of detection (LOD)—were calculated and compared between methods. By applying the theory of the propagation of random errors, LODs were determined to be 0.05 μL of saliva for the RSID? Saliva cards, 0.03 μL of saliva for Quantifiler^® Duo, and 0.001 μL of semen for Quantifiler^® Duo. In conclusion, quantitative PCR was deemed a viable and effective screening method for subsequent DNA profiling due to its stability in different matrices, sensitivity, and low limits of detection.     

Tyrosine Hydroxylase TH01 9.3 Allele in the Occurrence of Sudden Infant Death Syndrome in Swiss Caucasians

Catecholamines, especially noradrenalin, are essential in the control of respiration and arousal. Thus, an impaired production of these neurotransmitters may contribute to the occurrence of sudden infant death syndrome (SIDS). The first step of the noradrenergic synthesis pathway is catalyzed by the enzyme tyrosine hydroxylase (TH). The TH‐encoding gene contains a tetrameric short tandem repeat in intron 1 (TH01), with allele 9.3 reported to be associated with SIDS in German infants. We investigated the allelic frequency of the TH01 marker in 171 Swiss SIDS infants and 500 healthy and gender‐matched Caucasian adults. In our study population, the allelic frequency of the 9.3 allele is similarly distributed in SIDS cases and controls (27.2% vs. 25.6%; p‐value = 0.562). Nevertheless, the TH‐encoding gene is only one of several genes involved in the noradrenergic biosynthesis pathway. Therefore, further genetic investigations are required with focus on the whole noradrenergic signaling system.     

A PCR marker Linked to a THCA synthase Polymorphism is a Reliable Tool to Discriminate Potentially THC‐Rich Plants of Cannabis sativa L.

Neither absolute THC content nor morphology allows the unequivocal discrimination of fiber cultivars and drug strains of Cannabis sativa L. unequivocally. However, the CBD/THC ratio remains constant throughout the plant's life cycle, is independent of environmental factors, and considered to be controlled by a single locus (B) with two codominant alleles (B_T and B_D). The homozygous B_T/B_T genotype underlies the THC‐predominant phenotype, B_D/B_D is CBD predominant, and an intermediate phenotype is induced by the heterozygous state (B_T/B_D). Using PCR‐based markers in two segregating populations, we proved that the THCA synthase gene represents the postulated B locus and that specific sequence polymorphisms are absolutely linked either to the THC‐predominant or the THC‐intermediate chemotype. The absolute linkage provides an excellent reliability of the marker signal in forensic casework. For validation, the species‐specific marker system was applied to a large number of casework samples and fiber hemp cultivars.     

SNPs在个体识别与表型预测中的研究进展

单核苷酸多态性（single nucleotide polymorphism,SNP）作为第三代遗传标记,具有分布广泛、突变率低、遗传稳定及易于自动化高通量快速检测分析的特点。同时,因其扩增片段长度短、不存在复制滑动,所以利于腐败降解、痕量检材的检测。随着研究的深入,SNPs在法医学领域受到了广泛重视,与表型（ABO血型、色素沉积及颅面形态）相关的SNPs有望用于预测嫌疑人的基本特征,为案件侦破提供新的思路。本文对近年来SNPs在个体识别和表型预测的研究进行总结,介绍该领域的研究进展,为法医学工作者提供参考。     

压力循环技术用于人指甲DNA提取及方法学评价

目的将压力循环技术（PCT）用于指甲DNA提取,并对方法学进行评价。方法收集10份人指甲样本,剪碎约为1mm×1mm大小,采用10%漂白粉水,10%SDS,10%漂白粉水,无菌水清洗样本。10份样本各分成两组,1组用压力循环技术处理,另1组不作处理,提取DNA经复合扩增并进行STR分型检测,用于评价压力循环技术的作用。取5份指甲样本用血浸泡,5份用去离子水浸泡,之后采用上述清洗方法各清洗1-3次,收集各次清洗用的无菌水提取DNA,经STR分型检测,用于评价清洗对去除外源性DNA的效果。结果 10份经压力循环技术处理的样本中有7例比相应未经处理样本DNA提取量更高,但两组进行统计学处理,差异不具有统计学意义（P〉0.05）;两组样本中提取DNA含量在0.026 ng以上的样本均得到完整的STR分型,与相应口腔拭子样本对照准确无误。血污染和非血污染样本清洗二次以上,均可避免外源性DNA的污染。结论使用压力循环技术并配合本文清洗方法,可有效提高人指甲DNA的提取效率,并避免外源性生物DNA的干扰,保证DNA分型结果的准确。     

PowerPlex 21与GoldeneyeTM 20A试剂盒的一致性验证及法医学应用

目的：确认PowerPlex 21试剂盒与GoldeneyeTM 20A试剂盒分型结果的一致性。方法应用两试剂盒对205名北京汉族无关个体血样DNA进行复合扩增,观察19个重叠STR基因座分型的一致性,并统计D1S1656的遗传多态性。结果所有19个重叠基因座分型相同,两个试剂盒的杂合基因座峰高比例差异无统计学意义（P〉0.05）。D1S1656杂合度为0.878,个人识别率为0.949,三联体非父排除率为0.751,二联体非父排除率为0.506,多态信息含量为0.810。结论 PowerPlex21试剂盒与GoldeneyeTM 20A试剂盒分型结果一致性好,引物设计合理;D1S1656多态性好,可用于人类遗传分析及法医学中的亲子鉴定和个人识别。     

颅脑损伤修复机制与载脂蛋白E基因多态性的研究进展

颅脑损伤是一种由暴力作用于头颅引起的损伤,由致伤外力作用于头部所导致的颅骨、脑膜、脑血管和脑组织的机械形变。载脂蛋白E（apolipoproteins E,ApoE）是载脂蛋白的一个重要类型,参与机体脂质代谢及胆固醇平衡的调节。近年来发现,ApoE的基因多态性与多种疾病相关,其免疫反应性与脑损伤时间有关联,神经系统的正常生长和损伤后修复都具有一定规律性。本文对ApoE的生物学特性、脑损伤后的作用机制以及在法医学中的应用前景进行综述,希望为脑创伤时间推断及其相关实验研究提供新的思路。     

湖北地区汉族人群24个 Y-STR基因座遗传多态性研究

目的 对湖北汉族人群24个Y-STR基因座多态性进行调查,并获得相关的基础遗传学数据.方法 应用AGCU Y24 STR荧光标记复合直接扩增系统及3130XL型DNA测序仪,对湖北地区320对已确定父子关系的640个男性个体血样进行24个Y-STR检测分型.结果 在320名父亲男性个体中,在DYS391、DYS389工、DYS439、DYS389Ⅱ、DYS438、DYS449、DYS456、DYS458、DYS437、DYS635、DYS448、Y-GATA-H4、DYS447、DYS19、DYS392、DYS522、DYS393、DYS388、DYS390、DYS444基因座在湖北地区汉族人群分别检出4～17个等位基因,DYS527a/b检出45个等位基因组,DYS385a/b检出57个等位基因组,各基因座基因多样性最低为0.3838,最高为0.9650;并检出320种单倍型.比对320对父子Y-STR分型,在7680次基因遗传传递中,在DYS449、DYS527、DYS444、DYS389Ⅱ、DYS447、DYS522、DYS385、Y-GATA-H4等10个基因座中检出16个突变,突变率为1.5625‰～1.5653％,平均突变率为2.0833‰;等位基因增加突变与等位基因减少突变比为1∶1.结论 24个基因座单倍型在湖北地区汉族人群中具有丰富的遗传多态性,其数据对法医学应用、Y-STR数据库建设和群体遗传学等研究应用具有重要意义.     

河南汉族人群27个Y-STR基因座遗传多态性

目的 调查27个Y-STR基因座在河南汉族男性人群中的遗传多态性.方法 应用Yfiler（R） Plus试剂盒,对河南地区1100名汉族男性无关个体血样进行PCR扩增,3500XL型遗传分析仪电泳检测,GeneMapper-ID-X软件进行等位基因分型.结果 1100名男性共检出1098种不同的单倍型,其中1094种为单一型,另有3种单倍型均检出2例,HD（单倍型）值为0.999995;27个Y-STR基因座的GD值为0.3833～0.9663.结论 27个Y-STR基因座多数在河南汉族男性人群中有较好分布,对法医学应用和人类群体遗传学研究具有重要价值.