DYF155S1基因座的法医学应用研究

目的探讨Y染色体小卫星DYF155S1基因座在法医学中的应用价值。方法采用荧光MVR-PCR和Amp-FLP技术。结果同一个体不同组织所获得的分型结果一致;本方法能作出正确分型的最低基因组DNA量为0.3 ng;在女性成份为男性成份100倍的混合DNA样本(总DNA量多少为110 ng)中能正确检出DYF155S1基因型;调查130个父系家庭的男性成员样品(减数分裂336次),总共发现DYF155S1基因座有3次突变,突变率为0.9%。对强奸案混合斑的分析,可直接检出DYF155S1基因型。但是,本方法只能区分哺乳类雄性动物与非哺乳类动物。结论采用荧光MVR-PCR和Amp-FLP方法分析Y染色体小卫星DYF155S1基因座,方法可靠,灵敏度高,对混合斑和微量检材中男性DNA的分析具有较高的应用价值。     

Y染色体3个SNP基因座及其单倍型的遗传多态性和群体差异

目的 探讨人类Y染色体3个SNP基因座及其单倍型的遗传多态性和群体差异。方法 应用PCR-RFLPs结合DNA序列分析技术,对140例来自中国藏族、日本、南非黑人及南非白人男性的Y染色体M4、M9和M122基因座的等位基因进行分析。结果 全部样品M4基因座的等位基因均为野生型M4A,未发现多态性。共检出3种单倍型,黑人个体均为野生型单倍型M4A/M9C/M122T。白人个体有8例单倍型为M4A/M9G/M122T,未检出等位基因M122C。日本及中国藏族群体以单倍型M4A/M9C/M122T为主,频率分别为0.50和0.65,未检出单倍型M4A/M9C/M122C,个人识别机率与父权排除率分别为0.6191和0.4994。单倍型频率分布在中国藏族和日本群体之间存在显著性差异(P<0.01)。结论 单倍型M4A/M9G/M122C为亚洲人特征,M9和M122基因座在中国藏族和日本群体中具有较高的遗传多态性,并显示出明显的人种和群体差异。     

Mitochondrial diversity of a northeast German population sample

Mitochondrial DNA sequences of the hypervariable regions HV I and HV II were analyzed in 300 unrelated individuals born and living in the northeast corner of Germany (Western Pomerania) to generate a database for forensic identification purposes in this region. Sequence polymorphism were detected using PCR and direct sequencing analysis. A total of 242 different haplotypes were found as determined by 147 variable positions. The most frequent haplotype (263G, 315.1C) was found in 10 individuals and is also the most common sequence in Europe. Three other haplotypes were shared by 5 individuals, 2 sequences by 4, 8 haplotypes by 3, 15 sequences by 2 persons, and 213 sequences were unique. The genetic diversity was estimated to be 0.99 and the probability of two random individuals showing identical mitochondrial DNA (mtDNA) haplotypes is 0.6%. A comparison with other studies from Germany showed only little differences in the distribution of haplogroups. Nevertheless, one frequent haplotype in northeast Germany (five unrelated individuals) could only rarely be found in other German and European regions. Our results may indicate that despite a high admixture proportion in the German population some regions could demonstrate certain characteristic features.     

广东汉族人群H19基因上游差异甲基化区SNP

目的调查广东汉族人群中H19基因上游差异甲基化区(differentially methylated region,DMR)的单核苷酸多态性(SNP)及单倍型。方法应用PIA分型法,以限制性内切酶Mcr BC、HpaⅡ消化基因组DNA分别获得个体单亲源DNA模板链,经测序,分别获得个体H19基因上游DMR单亲源SNP等位基因、基因型及单倍型数据。结果共检出13个SNP(rs10840167、rs2525883、rs12417375、rs4930101、rs2525882、rs2735970、rs2735971、rs11042170、rs2735972、rs10732516、rs2071094、rs2107425、rs4930098)及1个突变点(g7351c)。所有位点经统计学分析均符合Hardy-Weinberg平衡定律(P0.05)。除rs12417375位点DP值为0.279,其余12个SNP DP值在0.446~0.614;g7351c突变点DP值为0.013,提示为南方汉族民族特异性位点。共检出8种单倍型(命名为单倍型1~8),其中有3种为新发现的单倍型,其DP、PIC、PE及H分别为0.891、0.714、0.524和0.758。结论 PIA分型法获得的H19基因上游DMR SNP位点及其单倍型遗传标记系统具有较高的鉴别能力,在法医学鉴定中具有较好的实用价值。     

Geographical heterogeneity of Y-chromosomal lineages in Norway

Y-chromosomal variation at five biallelic markers (Tat, YAP, 12f2, SRY(10831) and 92R7) and nine multiallelic short tandem repeat (STR) loci (DYS19, DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393, DYS385I/II and DYS388) in a Norwegian population sample are presented. The material consists of 1766 unrelated males of Norwegian origin. The geographical distribution of the population sample reflects fairly well the population distribution around the year 1942, which is the median birth year of the index persons. Seven hundred and twenty-one different Y-STR haplotypes but 726 different lineages (Y-STRs plus biallelic markers) were encountered. We observed six known (P*(xR1a), BR(xDE, J, N3, P), R1a, N3, DE, J), and one previously undescribed haplogroup (probably a subgroup within haplogroup P*(xR1a)). Four of the haplogroups (P*(xR1a), BR(xDE, J, N3, P), R1a and N3) represented about 98% of the population sample. The analysis of population pairwise differences indicates that the Norwegian Y-chromosome distribution most closely resembles those observed in Iceland, Germany, the Netherlands and Denmark. Within Norway, geographical substructuring was observed between regions and counties. The substructuring reflects to some extent the European Y-chromosome gradients, with higher frequency of P*(xR1a) in the south-west and of R1a in the east. Heterogeneity in major founder groups, geographical isolation, severe epidemics, historical trading links and population movements may have led to population stratification and have most probably contributed to the observed regional differences in distribution of haplotypes within two of the major haplogroups.     

Population genetics of Y-chromosome STRs in a population sample of the Lithuanian minority residing in the northeastern Poland

Haplotype and allele frequencies for the 12 Y-STRs were determined in a population sample of 124 unrelated males--members of the Lithuanian minority residing in the northeastern Poland. Three of the haplotypes were encountered in duplicate, while 118 haplotypes were unique. The overall gene diversity was 0.9952. Analysis of molecular variance revealed that the Lithuanian minority can be distinguished from the autochthonous Poles, although these two populations are very close to each other. This database study provides an essential precondition for applying Y-chromosomal STRs estimates in forensic identification of male DNA and tracing of paternal lineages.     

Haplotype of 12 Y-STR loci of the PowerPlex Y-system in Sichuan Han ethnic group in west China

Haplotypes and allele frequencies for 12 Y-STR loci were determined in Sichuan Han ethnic population samples of 237 unrelated males living in west China. Only one haplotype was encountered in triple. Twelve of the haplotypes were encountered in duplicate, while 210 haplotypes were unique. The gene diversity was 0.9952. This study provides an essential precondition for identification of male DNA and tracing of paternal lineages.     

Individual Identification of Racehorses from Urine Samples Using a 26‐Plex Single‐Nucleotide Polymorphism Assay

To construct a system for identifying individual horses from urine samples that are submitted for postracing doping tests, we developed a genotyping assay based on 26‐plex single‐nucleotide polymorphisms (SNPs). DNA was isolated from urine using a commercially available DNA/RNA extraction kit, and SNP genotyping was achieved with a SNaPshot^? technique. DNA profiles including 26 SNPs were acquired from urine samples and blood/hair samples. Within the studied Thoroughbred population, the 26‐plex assay showed a probability of identity of 5.80 × 10^?11. Compared to the conventional short tandem repeat assay, the SNP assay used less DNA, and the rate of successful genotyping was improved to 97% using aliquots of horse urine as small as 140 μL. The urinary DNA could be successfully genotyped under proper storage concerning refrigeration or freeze–thawing. This SNP assay can be used for individual identification when suspicious results are obtained from horse doping tests.     

Forensic genetic analysis of mitochondrial DNA hypervariable region I/II sequences: an expanded Korean population database

We have analyzed variation of the mitochondrial DNA (mtDNA) hypervariable segments I and II (HVS-I and HVS-II) in 185 randomly chosen individuals from Korea to provide an expanded and reliable Korean database. Combined sequence comparison of HVS-I and HVS-II led to the identification of 167 different haplotypes characterized by 154 variable sites. One hundred and fifty-one of the haplotypes were individual-specific, 14 were found in two individuals and 2 were found in three individuals. A pairwise comparison of the 185 HVS-I/II sequences found an average of 10.11 +/- 4.63 differences between individuals. The random match probability and gene diversity for the combined hypervariable regions were estimated at 0.66% and 0.9988, respectively. Analyzing the expanded database including three previously reported data sets and the present data using haplogroup-based comparisons and comparison with closely related sequences allowed errors to be detected and eliminated, thus considerably improving data quality. Sample division comparisons based on PhiST genetic distance measures revealed no significant population differentiation in the distribution of mtDNA sequence variations between the present data set and a database in The Scientific Working Group on DNA Analysis Methods (SWGDAM), but did indicate differences from other sets of data. Based on the results of mtDNA profiles, almost all of the mtDNA types studied here could be classified into subsets of haplogroups common in east Asia, and show that the Koreans possess lineages from both the southern and the northern haplogroup complexes of east Asian populations. The new data, combined with other mtDNA sequences, demonstrate how useful comparison with closely related mtDNA sequences can be for improving database quality, as well as providing haplotype information for forensic and population genetic analyses in the Korean population.     

D18S51及其侧翼区3个SNP组成的SNP-STR在亲子鉴定中的应用

目的将一个单倍型区块内的遗传标记单核苷酸多态性(SNP)和短串联重复序列(STR)组成SNPSTR单倍型,调查其在成都汉族人群中的分布,并探讨其在特殊亲子鉴定案例中的应用价值。方法选取DNA联合索引系统(combined DNA index system,CODIS)中突变率较高的基因座D18S51,与其侧翼区的3个SNP位点(rs8089331、rs8094489、rs7236090)组成SNP-STR,通过巢式等位基因特异性PCR的方法获得SNP-STR单倍型,调查该单倍型在75名成都汉族人群中的分布,并应用于两例D18S51基因座不符合遗传规律的二联体亲子鉴定案件。结果成功建立SNP-STR分型方法,在成都汉族人群中共发现43种单倍型,多态性为0.948 6,并成功解决了两例二联体亲子鉴定案件。结论 SNP-STR具有良好的多态性,有望应用于特殊的亲缘关系鉴定。     

Quantitative and qualitative analysis of DNA extracted from postmortem muscle tissues

DNA extracted from 33 postmortem muscle specimens was analyzed using MZ 1.3, a hypervariable minisatellite probe, as well as locus-specific minisatellite probes (g3, MS1 and MS43). After storage at -25 degrees C for 10 months, DNA from all the samples was partially (approximately 21% of total DNA) degraded even when autopsy was performed 1 day postmortem. However, more than 90% of DNA samples up to at least 3 days postmortem were suitable to obtain good restriction fragment length polymorphism (RFLP) patterns. When small strips of specimen were stored for 8 days at room temperature in moist chambers, approximately 42% of total DNA was degraded. Only 30% of these DNA samples still showed good RFLP patterns. However, no obvious relation between qualities of DNA analyzed by detection of RFLP and quantities of total and high-MW DNA became apparent. A case of familial relationship was ascertained by DNA fingerprints. Since DNA of good quality can be recovered from muscle tissues in large quantities, DNA extraction from muscle tissues and detection of RFLP patterns should be very useful for individual identification in autopsy cases.     

Sequence polymorphism of mitochondrial D-loop DNA in the Taiwanese Han population

In order to demonstrate the sequence diversity of mitochondrial D-loop DNA in the Taiwanese Han population, we established a database of 155 unrelated individuals. For each individual, the complete 980bp DNA region from the 5' end of HVI to 3' end of HVII segment was sequenced. In these 155 sequence data, 149 different haplotypes were observed, amongst these haplotypes, 144 were unique, 4 were found in 2 individuals and 1 was found in 3 individuals. When compare to the Anderson sequence, 144 transitions, 24 transversions, 5 insertions and 5 deletions were found. Eight positions exhibited more than one polymorphic sequence, six exhibited two variants while two exhibited three variants. Over the 1024bp that was analysed, pairwise differences between the sequences were 11.35+/-3.53bp. The sequence and nucleotide diversity were 0.9994 and 0.0116, respectively. The probability of two individuals randomly matching over the entire control region was 0.007. The diversity in the mitochondrial D-loop indicates the value of this locus for casework within Taiwan.     

印记基因H19上游高甲基化区SNPs多态性研究

目的建立简单、高效的DNA甲基化标记和SNPs联合检测技术，并用于H19基因上游高甲基化区两组SNPs群体遗传学检测。方法用PCR—DGGE技术对232例武汉汉族无关个体H19基因上游启动子区H19FR1和H19FR2单倍型进行检测；同时选用两种甲基化敏感的限制酶（msRE）HpaⅡ和HhaⅠ，检测H19FR等位基因亲代来源。结果H19FR1区检出5种单倍型、9种表型组合，其个体识别能力（DP）、多态性信息含量（PIC）和非父排除率（PE）分别为0．803、0．58和0．322；H19FR2区检出2种单倍型、3种表型组合，其DP、PIC和PE值分别为0．626、0．37和0．162。测序结果显示，片段H19FR1含有a7342g、a7357g和g7547a3个SNPs与1个g7351c点突变；H19FR2仅含aS097g1个SNP。msREHpaⅡ或HhaⅠ可消化个体母源等位基因，PDP-DGGE分析仅能检测到父源等位基因。结论PDP-DGGE是一种简单、灵敏、高效的DNA甲基化标记和SNPs联合分析技术，其在进行多态性分型同时还可以确定等位基因的亲代来源，具有较高的法医学应用价值。     

Population genetics of Y-chromosome STRs in a population of Podlasie, Northeastern Poland

Haplotype and allele frequencies for the 12 Y-STRs were determined in a population sample of 186 Polish males. Five of the haplotypes were encountered in duplicate, while 176 haplotypes were unique. The overall gene diversity was 0.9973. This database study provides an essential precondition for applying Y-chromosomal STRs estimates in forensic identification of male DNA and tracing of paternal lineages.     

The EDNAP mitochondrial DNA population database (EMPOP) collaborative exercises: organisation, results and perspectives

This paper presents an overview of the organisation and the results of the collaborative exercises (CE) of the European DNA Profiling (EDNAP) Group's mitochondrial DNA population database project (EMPOP). The aim of the collaborative exercises was to determine whether uniformity of mtDNA sequencing results could be achieved among different laboratories. These were asked to sequence either the complete mtDNA control region or the two hypervariable regions HVI (16024-16365) and HVII (73-340) from DNA extracts, buccal swabs or bloodstains, proceeding in accordance with the protocol and strategies used in each individual laboratory. The results of the collaborative exercises were employed to identify possible sources of errors that could arise during the analysis and interpretation of mtDNA profiles. These findings were taken as a basis to tentatively make suitable arrangements for the construction of a high quality mtDNA database. One hundred fifty mtDNA profiles were submitted to the evaluating laboratory, and disaccording profiles were classified into four groups corresponding to the source of error: clerical errors, sample mix-ups, contaminations and discrepancies with respect to the mtDNA nomenclature. Overall, 14 disaccording haplotypes (16 individual errors) were observed. The errors included 10 clerical errors, 3 interpretation problems, 2 cases of sample mix-up and 1 case of point heteroplasmic mixture, where the 2 sequencing reactions brought inconsistent base calls. This corresponds to an error rate of 10.7% in a virtual mtDNA database consisting of the collaborative exercise results. However, this estimate is still conservative compared to conclusions drawn by authors of meanwhile numerous publications critically reviewing published mtDNA population databases. Our results and earlier published concerns strongly emphasize the need for appropriate safety regulations when mtDNA profiles are compiled for database purposes in order to accomplish the high standard required for mtDNA databases that are used in the forensic context.     

中国人D7S21基因应5′端侧翼DNA多态性

分析D7S21基因座5’端侧翼DNA3个基因座多态性（－4A／G、－109C／T和一22lG／C）和单倍体分型。用PCR和扩增产物限制性内切酶酶解的方法检测了100名中国人无关个体的多态性,获得了6个不同等位基因的频率,即-4A＝0．29,－4G＝0．71,－109C＝0．54,－109T＝0．46,－221G＝0．74,－221C＝0．26。结果表明,D7SZI基因座5’端侧翼DNA3个基因座的DP值达0．944,在法医学个体识别中具有很高的个体识别能力。     

A distinct Y-STR haplotype for Amelogenin negative males characterized by a large Y(p)11.2 (DYS458-MSY1-AMEL-Y) deletion

The use of STR multiplexes with the incorporated gender marker Amelogenin is common practice in forensic DNA analysis. However, when a known male sample shows a dropout of the Amelogenin Y-allele, the STR system falsely genotypes it as a female. To date, our laboratory has observed 18 such cases: 12 from our Y-STR database and six from casework. A study on 980 male individuals in the Malaysian population using the AmpFlSTR Y-filer has revealed a distinct Y-chromosome haplotype associated with the Amelogenin nulls. Our results showed that whilst the Amelogenin nulls were noticeably absent among the Chinese, both the Indians and Malays exhibited such mutations at 3.2 and 0.6%, respectively. It was also found that the Amelogenin negative individuals predominantly belonged to the J2e lineage, suggesting the possibility of a common ancestor for at least some of these chromosomes. The null frequencies showed concordance with the data published in Chang et al. [Higher failures of Amelogenin sex test in an Indian population group, J. Forensic Sci. 48 (2003) 1309-1313] on a smaller Malaysian population of 338 males which used a Y-STR triplex. In the current study, apart from the absence of the Amelogenin Y-locus, a complete absence of the DYS458 locus in all the nulls was also observed. This study together with the 2003 study has indicated a similar deletion region exists on the Y(p)11.2 band in all the 18 Y-chromosomes. Using bioinformatics, this deletion has been mapped to a region of at least 1.13 Mb on the Y(p)11.2 encompassing the Amelogenin, MSY1 minisatellite and DYS458 locus. Further, the Y-filer haplotypes revealed an additional null at Y-GATA H4 in two of the Indian males presented here.     

Experimental long-distance haplotyping of OCA2-HERC2 variants

The regulatory HERC2 SNP, rs12913832, is strongly associated with blue and brown eye colour. However, eye colour in heterozygous rs12913832 individuals is observed to vary greatly. Missense mutations in OCA2, such as rs1800407 and rs74653330, are associated with lighter eye colour in some but not all heterozygous rs12913832 individuals. Determining the physical linkage of these variants might help to further explain eye colour variation. So far, experimental haplotyping of these variants has been challenging because the genomic distance between them (∼ 135 kb) exceeds the fragment lengths produced by commonly used DNA isolation kits. The aim for this study was to explore novel methods for long distance haplotyping to assess associations between OCA2-HERC2 haplotypes and eye colour. DNA was isolated from frozen blood samples collected from Norwegians that are known to be heterozygous for both HERC2 rs12913832 and OCA2 SNPs, either rs1800407 (n = 23) or rs74653330 (n = 17), using the newly commercially available Monarch® HMW (heigh molecular weight) DNA Extraction Kit (New England BioLabs_inc). We successfully isolated DNA fragments up to 210 kb, which were long enough to haplotype OCA2-HERC2 loci by droplet digital PCR (ddPCR). Three haplotypes were observed in the study population: rs12913832:A-rs1800407:T in 22/23 individuals, rs12913832:A-rs1800407:C in 1/23 individuals and rs12913832:A-rs74653330:T in 16/16 individuals. As expected, all individuals with the rs12913832:A-rs74653330:T haplotype had intermediate to blue eye colour. However, the rs12913832:A-rs1800407:T haplotype was observed in both blue and brown-eyed individuals, suggesting more research is needed.     

Successful STR and SNP typing of FTA Card samples with low amounts of DNA after DNA extraction using a Qiagen BioRobot EZ1 Workstation

FTA Cards (GE Healthcare) have been used for more than 4 years in Denmark for the collection of buccal cells as reference samples in crime cases. Semi-automated protocols for STR typing of DNA on punches of FTA Cards are routinely used. In average, full STR profiles were generated from approximately 95% of the FTA Cards with a standard punching protocol, while partial or no STR profile were obtained from 5% of the samples. Here, the Qiagen BioRobot^® EZ1 Workstation (Qiagen) and the EZ1 DNA Investigator Kit (Qiagen) was used to extract DNA from 29 FTA Cards from which a complete STR profile was not generated with the standard punching protocol. All 29 samples were successfully typed with the AmpF?STR^® Identifiler™ PCR Amplification Kit (Applied Biosystems) and with the SNPforID 49plex SNP assay. The lowest amount of DNA that resulted in complete STR and SNP profiles was 80 pg. The STR and SNP profiles were identical to those generated from another sample collected from each of the 29 individuals.     

High-throughput DNA sequencing of environmentally insulted latent fingerprints after visualization with nanoscale columnar-thin-film technique

The goals of this study were to (a) ascertain human identity capabilities of DNA obtained from latent fingerprints that have been first environmentally insulted and then developed by the deposition of a columnar thin film (CTF), and (b) to determine if the CTF process and material are detrimental to single nucleotide polymorphism (SNP) analysis. Fingerprints were deposited on five different types of substrates and aged for one day, 7 days or 30 days while being environmentally insulted under one of the four conditions: 16.6 °C and 60% relative humidity (RH) (Condition A), 24.5 °C and 60% RH (Condition B), 35 °C and 67% RH (Condition C) and a cold condition (Condition D). Then CTF technique was then on 59% of these fingerprints. DNA samples from 805 fingerprints were extracted, quantified, subjected to manual library preparation using the Precision ID Identity Panel, and underwent high-throughput sequencing. The Ion S5™ platform was employed to sequence 124 SNP amplicons. SNPs were successfully sequenced from 802/805 samples. Total read depth was consistent across environmental conditions, and majority of samples had 100% profile completeness and 100% concordance. Anecdotally, libraries that were amplified with a higher cycle number had more ‘Major Allele Frequency’ flags compared to samples amplified with 23 cycle numbers, possibly due to stochastic effects. Neither the substrates nor the CTF process and materials inhibit downstream DNA analysis. DNA of low quality and quantity from the chosen samples can be sequenced using the Precision ID Identity Panel on the Ion S5™ platform which performed well, however, a different approach may be needed if spurious alleles are suspected.