Forensic Science International-Genetics最新文献_第5页

A multi-class support vector machine classification model based on 14 microRNAs for forensic body fluid identification 基于 14 种 microRNA 的多类支持向量机分类模型用于法医体液鉴定

IF 3.2 2区医学 Q2 GENETICS & HEREDITY

Forensic Science International-Genetics

Pub Date : 2024-11-21 DOI: 10.1016/j.fsigen.2024.103180

Suyu Li , Jing Liu , Wei Xu , Shuyuan Zhang , Mengyao Zhao , Lu Miao , Minxiao Hui , Yuan Wang , Yiping Hou , Bin Cong , Zheng Wang

MicroRNAs (miRNAs) are promising biomarkers for forensic body fluid identification owing to their small size, stability against degradation, and differential expression patterns. However, the expression of most body fluid-miRNAs is relative (differentially expressed in certain body fluids) rather than absolute (exclusively expressed in a specific body fluid). Moreover, different body fluids contain heterogeneous cell types, complicating their identification. Therefore, appropriate normalization strategies to eliminate non-biological variations and robust models to interpret expression levels accurately are necessary prerequisites for applying miRNAs in body fluid identification. In this study, the expression stability of six candidate reference genes (RGs) across five body fluids was validated using geNorm, NormFinder, BestKeeper and RankAggreg, and the most suitable combination of RGs (hsa-miR-484 and hsa-miR-191–5p) was identified under our experimental conditions. Subsequently, we systematically evaluated the expression patterns of the 28 most promising body fluid-specific miRNA markers using TaqMan RT-qPCR and selected the optimal combination of markers (12 miRNAs) to establish a multi-class support vector machine (MSVM) classification model. An independent test set (60 samples) was used to validate the accuracy of the proposed classification model, while an additional 30 casework samples were used to assess its robustness. The MSVM model accurately predicted the body fluid origin for almost all (59/60) single-source samples. Moreover, this model demonstrated the capability to identify aged forensic samples and to predict the primary components of mixed stains to a certain extent. In summary, this study presented a miRNA-based MSVM classification model for forensic body fluid identification using the qPCR platform. However, extensive validation, especially inter-laboratory collaborative exercises, is necessary before miRNA can be routinely applied in forensic identification practice.

微小核糖核酸（miRNA）体积小，具有抗降解稳定性和不同表达模式，是法医鉴定体液鉴定的有前途的生物标志物。然而，大多数体液-miRNA 的表达是相对的（在某些体液中表达不同），而不是绝对的（只在特定体液中表达）。此外，不同的体液含有不同的细胞类型，这也使它们的鉴定变得复杂。因此，要在体液鉴定中应用 miRNA，必须有适当的归一化策略来消除非生物变异，并建立稳健的模型来准确解释表达水平。本研究利用 geNorm、NormFinder、BestKeeper 和 RankAggreg 验证了六个候选参考基因（RGs）在五种体液中的表达稳定性，并在实验条件下确定了最合适的 RGs 组合（hsa-miR-484 和 hsa-miR-191-5p）。随后，我们使用 TaqMan RT-qPCR 系统评估了 28 个最有希望的体液特异性 miRNA 标记的表达模式，并选出了标记的最佳组合（12 个 miRNA），建立了多类支持向量机（MSVM）分类模型。一个独立的测试集（60 个样本）被用来验证所提议的分类模型的准确性，另外 30 个病例样本被用来评估其稳健性。MSVM 模型准确预测了几乎所有（59/60）单一来源样本的体液来源。此外，该模型还展示了识别陈年法医样本的能力，并在一定程度上预测了混合污渍的主要成分。总之，本研究利用 qPCR 平台提出了一种基于 miRNA 的 MSVM 分类模型，用于法医体液鉴定。然而，在 miRNA 常规应用于法医鉴定实践之前，还需要进行广泛的验证，特别是实验室之间的合作。

{"title":"A multi-class support vector machine classification model based on 14 microRNAs for forensic body fluid identification","authors":"Suyu Li , Jing Liu , Wei Xu , Shuyuan Zhang , Mengyao Zhao , Lu Miao , Minxiao Hui , Yuan Wang , Yiping Hou , Bin Cong , Zheng Wang","doi":"10.1016/j.fsigen.2024.103180","DOIUrl":"10.1016/j.fsigen.2024.103180","url":null,"abstract":"<div><div>MicroRNAs (miRNAs) are promising biomarkers for forensic body fluid identification owing to their small size, stability against degradation, and differential expression patterns. However, the expression of most body fluid-miRNAs is relative (differentially expressed in certain body fluids) rather than absolute (exclusively expressed in a specific body fluid). Moreover, different body fluids contain heterogeneous cell types, complicating their identification. Therefore, appropriate normalization strategies to eliminate non-biological variations and robust models to interpret expression levels accurately are necessary prerequisites for applying miRNAs in body fluid identification. In this study, the expression stability of six candidate reference genes (RGs) across five body fluids was validated using geNorm, NormFinder, BestKeeper and RankAggreg, and the most suitable combination of RGs (hsa-miR-484 and hsa-miR-191–5p) was identified under our experimental conditions. Subsequently, we systematically evaluated the expression patterns of the 28 most promising body fluid-specific miRNA markers using TaqMan RT-qPCR and selected the optimal combination of markers (12 miRNAs) to establish a multi-class support vector machine (MSVM) classification model. An independent test set (60 samples) was used to validate the accuracy of the proposed classification model, while an additional 30 casework samples were used to assess its robustness. The MSVM model accurately predicted the body fluid origin for almost all (59/60) single-source samples. Moreover, this model demonstrated the capability to identify aged forensic samples and to predict the primary components of mixed stains to a certain extent. In summary, this study presented a miRNA-based MSVM classification model for forensic body fluid identification using the qPCR platform. However, extensive validation, especially inter-laboratory collaborative exercises, is necessary before miRNA can be routinely applied in forensic identification practice.</div></div>","PeriodicalId":50435,"journal":{"name":"Forensic Science International-Genetics","volume":"75 ","pages":"Article 103180"},"PeriodicalIF":3.2,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142697389","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A molecular framework for enhancing quality control and sample integrity in forensic genome sequencing 加强法医基因组测序质量控制和样本完整性的分子框架。

IF 3.2 2区医学 Q2 GENETICS & HEREDITY

Forensic Science International-Genetics

Pub Date : 2024-11-19 DOI: 10.1016/j.fsigen.2024.103179

Steven A. Bates , Bruce Budowle , Lee Baker , Kristen Mittelman , David Mittelman

DNA typing is essential for identifying crime scene evidence and missing and unknown persons. Molecular tags historically have been incorporated into DNA typing reactions to improve result interpretation. Molecular tags like barcodes and unique identifiers are integral to MPS, aiding in sample tracking and error detection. However, these tags do not fully leverage sequence variation to enhance quality control. To address this need, molecular etches, which are synthetic oligonucleotides that serve as an internal molecular information management system, are introduced. Molecular etches encode detailed sample information improving sample workflow history, tracking, contamination detection, and authenticity verification. Validation studies demonstrate the robustness of molecular etches in genomic sequencing, making them a valuable quality tool for forensic DNA analysis.

DNA 分型对于识别犯罪现场证据和失踪及未知人员至关重要。历史上，分子标记曾被纳入 DNA 分型反应，以改进结果解读。条形码和唯一标识符等分子标签是 MPS 不可或缺的组成部分，有助于样本追踪和错误检测。然而，这些标记不能充分利用序列变异来加强质量控制。为了满足这一需求，我们引入了分子蚀刻技术，即作为内部分子信息管理系统的合成寡核苷酸。分子蚀刻可编码详细的样本信息，从而改善样本工作流程历史、跟踪、污染检测和真实性验证。验证研究证明了分子蚀刻在基因组测序中的稳健性，使其成为法医 DNA 分析的重要质量工具。

引用次数: 0

Benchmarking for genotyping and imputation using degraded DNA for forensic applications across diverse populations 利用降解 DNA 进行基因分型和估算，为不同人群的法医应用设定基准

IF 3.2 2区医学 Q2 GENETICS & HEREDITY

Forensic Science International-Genetics

Pub Date : 2024-11-17 DOI: 10.1016/j.fsigen.2024.103177

Elena I. Zavala , Rori V. Rohlfs , Priya Moorjani

Advancements in sequencing and laboratory technologies have enabled forensic genetic analysis on increasingly low quality and degraded DNA samples. However, existing computational methods applied to genotyping and imputation for generating DNA profiles from degraded DNA have not been tested for forensic applications. Here we simulated sequencing data of varying qualities–coverage, fragment lengths, and deamination patterns–from forty individuals of diverse genetic ancestries. We used this dataset to test the performance of commonly used genotype and imputation methods (SAMtools, GATK, ATLAS, Beagle, and GLIMPSE) on five different SNP panels (MPS-plex, FORCE, two extended kinship panels, and the Human Origins array) that are used for forensic and population genetics applications. For genome mapping and variant calling with degraded DNA, we find use of parameters and methods (such as ATLAS) developed for ancient DNA analysis provides a marked improvement over conventional standards used for next generation sequencing analysis. We find that ATLAS outperforms GATK and SAMtools, achieving over 90 % genotyping accuracy for the four largest SNP panels with coverages greater than 10X. For lower coverages, decreased concordance rates are correlated with increased rates of heterozygosity. Genotype refinement and imputation improve the accuracy at lower coverages by leveraging population reference data. For all five SNP panels, we find that using a population reference panel representative of worldwide populations (e.g., the 1000 Genomes Project) results in increased genotype accuracies across genetic ancestries, compared to ancestry-matched population reference panels. Importantly, we find that the low SNP density of commonly used forensics SNP panels can impact the reliability and performance of genotype refinement and imputation. This highlights a critical trade-off between enhancing privacy by using panels with fewer SNPs and maintaining the effectiveness of genomic tools. We provide benchmarks and recommendations for analyzing degraded DNA from diverse populations with widely used genomic methods in forensic casework.

随着测序和实验室技术的进步，对越来越多的低质量和降解 DNA 样本进行法医遗传分析成为可能。然而，现有的用于基因分型和从降解 DNA 中生成 DNA 图谱的计算方法尚未在法医应用中进行过测试。在这里，我们模拟了来自 40 个不同基因血统个体的不同质量的测序数据--覆盖率、片段长度和脱氨模式。我们使用该数据集测试了常用基因型和估算方法（SAMtools、GATK、ATLAS、Beagle 和 GLIMPSE）在五个不同 SNP 面板（MPS-plex、FORCE、两个扩展亲缘关系面板和人类起源阵列）上的性能，这些面板可用于法医和群体遗传学应用。我们发现，在使用降解 DNA 进行基因组图谱绘制和变异调用时，使用为古 DNA 分析开发的参数和方法（如 ATLAS）比使用新一代测序分析的传统标准有明显改善。我们发现 ATLAS 的表现优于 GATK 和 SAMtools，在覆盖率大于 10 倍的四个最大 SNP 面板中，其基因分型准确率超过 90%。对于较低的覆盖率，一致性率的降低与杂合率的增加相关。通过利用群体参考数据，基因型细化和估算提高了较低覆盖率下的准确率。对于所有五个 SNP 面板，我们发现与祖先匹配的人口参考面板相比，使用代表全球人口的人口参考面板（如 1000 基因组项目）可提高不同遗传祖先的基因型准确性。重要的是，我们发现常用法医 SNP 面板的 SNP 密度较低，这会影响基因型完善和归因的可靠性和性能。这凸显了通过使用 SNP 较少的面板来提高隐私性与保持基因组工具有效性之间的重要权衡。我们为在法医案件工作中使用广泛使用的基因组学方法分析来自不同人群的降解 DNA 提供了基准和建议。

{"title":"Benchmarking for genotyping and imputation using degraded DNA for forensic applications across diverse populations","authors":"Elena I. Zavala , Rori V. Rohlfs , Priya Moorjani","doi":"10.1016/j.fsigen.2024.103177","DOIUrl":"10.1016/j.fsigen.2024.103177","url":null,"abstract":"<div><div>Advancements in sequencing and laboratory technologies have enabled forensic genetic analysis on increasingly low quality and degraded DNA samples. However, existing computational methods applied to genotyping and imputation for generating DNA profiles from degraded DNA have not been tested for forensic applications. Here we simulated sequencing data of varying qualities–coverage, fragment lengths, and deamination patterns–from forty individuals of diverse genetic ancestries. We used this dataset to test the performance of commonly used genotype and imputation methods (SAMtools, GATK, ATLAS, Beagle, and GLIMPSE) on five different SNP panels (MPS-plex, FORCE, two extended kinship panels, and the Human Origins array) that are used for forensic and population genetics applications. For genome mapping and variant calling with degraded DNA, we find use of parameters and methods (such as ATLAS) developed for ancient DNA analysis provides a marked improvement over conventional standards used for next generation sequencing analysis. We find that ATLAS outperforms GATK and SAMtools, achieving over 90 % genotyping accuracy for the four largest SNP panels with coverages greater than 10X. For lower coverages, decreased concordance rates are correlated with increased rates of heterozygosity. Genotype refinement and imputation improve the accuracy at lower coverages by leveraging population reference data. For all five SNP panels, we find that using a population reference panel representative of worldwide populations (e.g., the 1000 Genomes Project) results in increased genotype accuracies across genetic ancestries, compared to ancestry-matched population reference panels. Importantly, we find that the low SNP density of commonly used forensics SNP panels can impact the reliability and performance of genotype refinement and imputation. This highlights a critical trade-off between enhancing privacy by using panels with fewer SNPs and maintaining the effectiveness of genomic tools. We provide benchmarks and recommendations for analyzing degraded DNA from diverse populations with widely used genomic methods in forensic casework.</div></div>","PeriodicalId":50435,"journal":{"name":"Forensic Science International-Genetics","volume":"75 ","pages":"Article 103177"},"PeriodicalIF":3.2,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142697382","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Estimation of population-specific values of theta for PowerPlex Y23 profiles PowerPlex Y23 图谱的特定人群θ值估算。

IF 3.2 2区医学 Q2 GENETICS & HEREDITY

Forensic Science International-Genetics

Pub Date : 2024-11-16 DOI: 10.1016/j.fsigen.2024.103175

John S. Buckleton , Taryn O. Hall , Jo-Anne Bright , Michael C. Yung , Jérôme Goudet , Maarten Kruijver , Bruce S. Weir

We examine 31,011 PPY23 profiles at the population, metapopulation and world levels. Most haplotypes appear only once but a few have higher counts, including a set of 23 matching profiles in Delhi, India and a set of 16 matching profiles in Burkina Faso with one additional matching American African profile. We estimate

F_{S T}

values to be used as “theta” (θ) in match probability calculations, following the method we used in our earlier survey of autosomal STR data. Match probability estimates using

{\hat{F}}_{S T}

or the κ method of Brenner for a previously unseen profile are similar but differ for any profile previously seen.

我们在种群、元种群和世界层面研究了 31011 个 PPY23 图谱。大多数单倍型只出现过一次，但也有少数单倍型出现的次数较多，包括印度德里的一组 23 个匹配型谱和布基纳法索的一组 16 个匹配型谱以及另外一个匹配的非洲裔美国人型谱。我们按照早先调查常染色体 STR 数据时使用的方法估算了 FST 值，并将其用作匹配概率计算中的 "θ"。使用 FˆST 或布伦纳（Brenner）的 κ 方法对以前未见过的特征进行的匹配概率估计是相似的，但对于以前见过的任何特征则不同。

引用次数: 0

Ethical and legal reflections on secondary research using genetic data acquired for criminal investigation purposes 对使用为刑事调查目的获取的基因数据进行二次研究的伦理和法律思考。

IF 3.2 2区医学 Q2 GENETICS & HEREDITY

Forensic Science International-Genetics

Pub Date : 2024-11-16 DOI: 10.1016/j.fsigen.2024.103178

Martin Zieger , Nathan Scudder

Research with human genetic data or human beings more generally requires valid informed consent. However, several exceptions exist to this universal principle, usually for situations where it is impossible or at least impractical to obtain this consent. Those exceptions are usually bound to requirements of necessity, shared benefit for the concerned community and minimization of harmful impact. Research without consent is normally subject to approval by an ethics review board. However, secondary use for research may also be based on statutory research privileges in the law. We identified several legal provisions in different countries, permitting the secondary use of DNA data that has been collected without consent for law enforcement purposes, which raises ethical questions. Most of the respective laws seem to be connected to privacy rules and permit the use of de-identified data only. However, whether individual DNA profiles in suspect and offender databases can actually be de-identified must be questioned. What appears to be less critical in terms of re-identification risk are the frequently mentioned "statistical indices", most likely referring to aggregated allele frequencies. However, reflections about data anonymity and a narrow purpose limitation to research aiming at the improvement of calculations of weight of evidence seem not to be the sole reasons for permitting research with entries from criminal offender databases. Distinctions between convicted offenders and other people in the database suggest an assumption of forfeiting some level of privacy protection upon conviction underlying some of these provisions. The use of entries on national DNA databases could therefore amount to problematic additional punishment.

对人类基因数据或人类进行研究，一般都需要获得有效的知情同意。不过，这一普遍原则也有几种例外情况，通常是在无法或至少不可能征得同意的情况下。这些例外情况通常受必要性、相关群体的共同利益和最大限度地减少有害影响等要求的约束。未经同意的研究通常须经伦理审查委员会批准。不过，二次用于研究也可能是基于法律规定的法定研究特权。我们在不同国家发现了一些法律规定，允许为执法目的二次使用未经同意收集的 DNA 数据，这就产生了伦理问题。大多数相关法律似乎都与隐私规则有关，只允许使用去标识化数据。然而，嫌疑人和罪犯数据库中的个人 DNA 资料是否真的可以去身份化，这一点必须受到质疑。经常提到的 "统计指数"（很可能指的是等位基因的总频率）在重新识别风险方面似乎不那么重要。然而，对数据匿名性的反思和对旨在改进证据权重计算的研究的狭隘目的限制似乎并不是允许使用罪犯数据库条目进行研究的唯一原因。已定罪罪犯与数据库中其他人之间的区别表明，其中一些规定所依据的假定是，一旦定罪，就会丧失某种程度的隐私保护。因此，使用国家 DNA 数据库中的条目可能构成有问题的额外惩罚。

{"title":"Ethical and legal reflections on secondary research using genetic data acquired for criminal investigation purposes","authors":"Martin Zieger , Nathan Scudder","doi":"10.1016/j.fsigen.2024.103178","DOIUrl":"10.1016/j.fsigen.2024.103178","url":null,"abstract":"<div><div>Research with human genetic data or human beings more generally requires valid informed consent. However, several exceptions exist to this universal principle, usually for situations where it is impossible or at least impractical to obtain this consent. Those exceptions are usually bound to requirements of necessity, shared benefit for the concerned community and minimization of harmful impact. Research without consent is normally subject to approval by an ethics review board. However, secondary use for research may also be based on statutory research privileges in the law. We identified several legal provisions in different countries, permitting the secondary use of DNA data that has been collected without consent for law enforcement purposes, which raises ethical questions. Most of the respective laws seem to be connected to privacy rules and permit the use of de-identified data only. However, whether individual DNA profiles in suspect and offender databases can actually be de-identified must be questioned. What appears to be less critical in terms of re-identification risk are the frequently mentioned \"statistical indices\", most likely referring to aggregated allele frequencies. However, reflections about data anonymity and a narrow purpose limitation to research aiming at the improvement of calculations of weight of evidence seem not to be the sole reasons for permitting research with entries from criminal offender databases. Distinctions between convicted offenders and other people in the database suggest an assumption of forfeiting some level of privacy protection upon conviction underlying some of these provisions. The use of entries on national DNA databases could therefore amount to problematic additional punishment.</div></div>","PeriodicalId":50435,"journal":{"name":"Forensic Science International-Genetics","volume":"75 ","pages":"Article 103178"},"PeriodicalIF":3.2,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142696138","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Validation of the IDseek® OmniSTR™ Global Autosomal STR Profiling kit, reverse complement PCR as an improved tool/method for routine massively parallel sequencing of short tandem repeats 验证 IDseek® OmniSTR™ 全球常染色体 STR 分析试剂盒，将反向互补 PCR 作为常规大规模并行测序短串联重复序列的改进工具/方法。

IF 3.2 2区医学 Q2 GENETICS & HEREDITY

Forensic Science International-Genetics

Pub Date : 2024-11-14 DOI: 10.1016/j.fsigen.2024.103174

Kristiaan J. van der Gaag , Natalie Weiler , Erik A.C. de Jong , Jerry Hoogenboom , Pieter van Oers , Rick H. de Leeuw , Elisabeth S.M. Graaf , Thirsa Kraaijenbrink , Joop Theelen , Titia Sijen

Massively Parallel Sequencing (MPS) has gained interest in the forensic community over the past decade. Most of the published MPS methods focus on specialty applications intended for use in a limited number of samples with protocols that are relatively laborious. Recent developments using Reverse-Complement PCR enable an efficient MPS protocol suited for routine analysis of high numbers of samples. This method is implemented in the IDseek® OmniSTR™ Global Autosomal STR Profiling kit (Nimagen) for sequencing 28 of the most commonly used forensic autosomal STRs, one Y-chromosomal STR and Amelogenin. This study describes the validation of this kit and focuses on sensitivity, inhibitor tolerance, sequence variation detection and performance with mixtures up to 5 contributors. Results are compared to a Capillary Electrophoresis method (the PowerPlex® Fusion 6 C system, Promega) and the first commercial forensic MPS kit (ForenSeq™ DNA Signature prep, Qiagen) and for a concordance study with data from the Powerseq® MPS kit as well. Analysis settings in FDSTools are deduced and discussed, and an almost completely automated analysis is achieved. Using FDSTools noise correction, contributions in a mixture down to a level of 1.5 % of the major allele of a marker can be detected.

过去十年来，大规模平行测序（MPS）在法医界越来越受到关注。大多数已发表的 MPS 方法都侧重于专业应用，旨在用于数量有限的样本，其方案相对费力。利用反向互补 PCR 技术的最新发展，使高效的 MPS 方案适用于大量样本的常规分析。IDseek® OmniSTR™ 全球常染色体 STR 分析试剂盒（Nimagen）采用了这种方法，对 28 种最常用的法医常染色体 STR、一种 Y 染色体 STR 和 Amelogenin 进行测序。本研究介绍了该试剂盒的验证情况，重点是灵敏度、抑制剂耐受性、序列变异检测和多达 5 个贡献者混合物的性能。研究结果与毛细管电泳方法（Promega 公司的 PowerPlex® Fusion 6 C 系统）和首个商用法医 MPS 试剂盒（Qiagen 公司的 ForenSeq™ DNA Signature 预处理）进行了比较，并与 Powerseq® MPS 试剂盒的数据进行了一致性研究。对 FDSTools 中的分析设置进行了推导和讨论，并实现了几乎完全自动化的分析。利用 FDSTools 的噪声校正功能，可以检测到混合物中低至 1.5 % 的标记物主要等位基因的贡献。

{"title":"Validation of the IDseek® OmniSTR™ Global Autosomal STR Profiling kit, reverse complement PCR as an improved tool/method for routine massively parallel sequencing of short tandem repeats","authors":"Kristiaan J. van der Gaag , Natalie Weiler , Erik A.C. de Jong , Jerry Hoogenboom , Pieter van Oers , Rick H. de Leeuw , Elisabeth S.M. Graaf , Thirsa Kraaijenbrink , Joop Theelen , Titia Sijen","doi":"10.1016/j.fsigen.2024.103174","DOIUrl":"10.1016/j.fsigen.2024.103174","url":null,"abstract":"<div><div>Massively Parallel Sequencing (MPS) has gained interest in the forensic community over the past decade. Most of the published MPS methods focus on specialty applications intended for use in a limited number of samples with protocols that are relatively laborious. Recent developments using Reverse-Complement PCR enable an efficient MPS protocol suited for routine analysis of high numbers of samples. This method is implemented in the IDseek® OmniSTR™ Global Autosomal STR Profiling kit (Nimagen) for sequencing 28 of the most commonly used forensic autosomal STRs, one Y-chromosomal STR and Amelogenin. This study describes the validation of this kit and focuses on sensitivity, inhibitor tolerance, sequence variation detection and performance with mixtures up to 5 contributors. Results are compared to a Capillary Electrophoresis method (the PowerPlex® Fusion 6 C system, Promega) and the first commercial forensic MPS kit (ForenSeq™ DNA Signature prep, Qiagen) and for a concordance study with data from the Powerseq® MPS kit as well. Analysis settings in FDSTools are deduced and discussed, and an almost completely automated analysis is achieved. Using FDSTools noise correction, contributions in a mixture down to a level of 1.5 % of the major allele of a marker can be detected.</div></div>","PeriodicalId":50435,"journal":{"name":"Forensic Science International-Genetics","volume":"74 ","pages":"Article 103174"},"PeriodicalIF":3.2,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142645274","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Concurrent genotyping of mitochondrial DNA and nuclear DNA in rootless hair shafts and blood samples for enhanced analysis 同时对无根毛轴和血液样本中的线粒体 DNA 和核 DNA 进行基因分型，以加强分析。

IF 3.2 2区医学 Q2 GENETICS & HEREDITY

Forensic Science International-Genetics

Pub Date : 2024-11-13 DOI: 10.1016/j.fsigen.2024.103176

Dan Peng , Nana Wang , Yu Zang , Zhiyong Liu , Zhentang Liu , Jiaojiao Geng , Bin Cong , Hongyu Sun , Riga Wu

Hair is an important type of biological evidence at crime scenes. However, the highly degraded nature of DNA fragments in hair shafts poses challenges for the detection of nuclear DNA (nuDNA) through capillary electrophoresis-based short tandem repeat (STR) genotyping. In this study, an all-in-one multiplex system named MGIEasy Signature Identification Library Prep Kit (MGI Tech, China) was employed to the simultaneous genotyping of both mitochondrial DNA (mtDNA) and nuDNA in hair shafts. This system is based on massively parallel sequencing (MPS) technology and encompasses Amelogenin, STRs, single nucleotide polymorphisms (SNPs) and mtDNA hypervariable regions (HVRs) in a single reaction. A total of 370 hair shafts, together with 180 blood samples as the references, were examined. The mtDNA analysis of 110 unrelated blood samples unveiled a total of 150 homoplasmic variants and 105 distinct haplotypes, revealing population polymorphisms in the Guangdong Han Chinese. The study also delved into the detection of mtDNA heteroplasmy, revealing 8.18 % and 16.36 % of individuals with point heteroplasmies (PHPs) in blood and hair shaft samples, respectively. Additionally, hair shafts with DNA extracted using the Investigator method yielded higher average depth of coverage (DoC), lower drop-out rate for SNP genotyping, higher nuDNA genotyped rates and success rates, than those using the MinElute method. In the longitudinal research, a gradual decrease in the total DoC of mtDNA fragments was observed along the length of the hair shaft, from the proximal root to the distal end. In contrast, the DoC of nuDNA exhibited a relatively stable pattern along the length of the hair shafts. The study contributes valuable insights into the simultaneous detection of nuDNA and mtDNA in hair shafts, emphasizing the need for optimized DNA extraction and detection methods for these highly degraded samples.

头发是犯罪现场的一种重要生物证据。然而，毛发中DNA片段的高度降解性给基于毛细管电泳的短串联重复（STR）基因分型检测核DNA（nuDNA）带来了挑战。本研究采用了一种名为 "MGIEasy Signature Identification Library Prep Kit "的多合一系统（MGIEasy Signature Identification Library Prep Kit，中国）来同时对毛发中的线粒体DNA（mtDNA）和nuDNA进行基因分型。该系统基于大规模并行测序（MPS）技术，在单次反应中包含淀粉样蛋白、STRs、单核苷酸多态性（SNPs）和 mtDNA 超变异区（HVRs）。共检测了 370 根毛干和 180 份血液样本作为参考。对 110 份无血缘关系的血液样本进行的 mtDNA 分析共发现 150 个同质变异和 105 个不同的单倍型，揭示了广东汉族的人群多态性。该研究还深入探讨了 mtDNA 异质体的检测，在血液和毛发样本中分别发现 8.18% 和 16.36% 的个体存在点异质体（PHPs）。此外，与使用 MinElute 方法的样本相比，使用 Investigator 方法提取 DNA 的毛发样本的平均覆盖深度（DoC）更高，SNP 基因分型的丢失率更低，nuDNA 基因分型率和成功率更高。在纵向研究中，观察到 mtDNA 片段的总 DoC 从近端发根到远端沿发干长度逐渐降低。与此相反，nuDNA 的 DoC 沿着毛干的长度呈现出相对稳定的模式。这项研究为同时检测发干中的 nuDNA 和 mtDNA 提供了宝贵的见解，强调了针对这些高度降解样本优化 DNA 提取和检测方法的必要性。

{"title":"Concurrent genotyping of mitochondrial DNA and nuclear DNA in rootless hair shafts and blood samples for enhanced analysis","authors":"Dan Peng , Nana Wang , Yu Zang , Zhiyong Liu , Zhentang Liu , Jiaojiao Geng , Bin Cong , Hongyu Sun , Riga Wu","doi":"10.1016/j.fsigen.2024.103176","DOIUrl":"10.1016/j.fsigen.2024.103176","url":null,"abstract":"<div><div>Hair is an important type of biological evidence at crime scenes. However, the highly degraded nature of DNA fragments in hair shafts poses challenges for the detection of nuclear DNA (nuDNA) through capillary electrophoresis-based short tandem repeat (STR) genotyping. In this study, an all-in-one multiplex system named MGIEasy Signature Identification Library Prep Kit (MGI Tech, China) was employed to the simultaneous genotyping of both mitochondrial DNA (mtDNA) and nuDNA in hair shafts. This system is based on massively parallel sequencing (MPS) technology and encompasses Amelogenin, STRs, single nucleotide polymorphisms (SNPs) and mtDNA hypervariable regions (HVRs) in a single reaction. A total of 370 hair shafts, together with 180 blood samples as the references, were examined. The mtDNA analysis of 110 unrelated blood samples unveiled a total of 150 homoplasmic variants and 105 distinct haplotypes, revealing population polymorphisms in the Guangdong Han Chinese. The study also delved into the detection of mtDNA heteroplasmy, revealing 8.18 % and 16.36 % of individuals with point heteroplasmies (PHPs) in blood and hair shaft samples, respectively. Additionally, hair shafts with DNA extracted using the Investigator method yielded higher average depth of coverage (DoC), lower drop-out rate for SNP genotyping, higher nuDNA genotyped rates and success rates, than those using the MinElute method. In the longitudinal research, a gradual decrease in the total DoC of mtDNA fragments was observed along the length of the hair shaft, from the proximal root to the distal end. In contrast, the DoC of nuDNA exhibited a relatively stable pattern along the length of the hair shafts. The study contributes valuable insights into the simultaneous detection of nuDNA and mtDNA in hair shafts, emphasizing the need for optimized DNA extraction and detection methods for these highly degraded samples.</div></div>","PeriodicalId":50435,"journal":{"name":"Forensic Science International-Genetics","volume":"75 ","pages":"Article 103176"},"PeriodicalIF":3.2,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142683245","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Improving the forensic genetic workflow for countries with small geographical areas: What are the options and how cost effective are they? 为地理面积较小的国家改进法医基因工作流程：有哪些选择，成本效益如何？

IF 3.2 2区医学 Q2 GENETICS & HEREDITY

Forensic Science International-Genetics

Pub Date : 2024-11-08 DOI: 10.1016/j.fsigen.2024.103171

Anabella De La Chica , Jason Birkett , Cynthia Akwei , David Lamont , Nick Dawnay

Forensic services worldwide often encounter considerable challenges relating to funding and infrastructure. Smaller jurisdictions or areas where forensic resources are scarce are faced with complicated choices in how they approach criminal casework, with a number of options available. Often these involve trade-offs between cost, time and data quality. Faced with such decisions it becomes important for the field to acknowledge the realities facing such jurisdictions, discuss the pros and cons of each approach, and identify a framework for making such decisions. This novel paper, reviews the available literature and identifies three main solutions for consideration: 1) the use of satellite laboratories for sample triage, 2) the use of a main regional laboratory for full forensic analysis and 3) the use of rapid DNA by police for reducing backlogs. Alongside these strategies, the impacts of cost and quality in regard to each of the stated options are considered. While the literature supports the assertion that some methods can reduce downstream costs via the reduction in turnaround times, there is limited data highlighting the business case used to support decision making when considering these options including the use of cost:benefit analyses or case studies, emphasizing the novelty of this paper. This is likely due to the commercialized nature of the forensic sector preventing the publication of a private laboratory’s business approach. The lack of emphasis on the ‘business case’ in forensic literature has the potential to mislead R&D scientists who may consequently fail to consider such factors when performing their own research.

世界各地的法医服务经常遇到资金和基础设施方面的巨大挑战。规模较小的司法管辖区或法医资源稀缺的地区在如何处理刑事案件工作方面面临着复杂的选择，可供选择的方案很多。这些选择往往涉及成本、时间和数据质量之间的权衡。面对这样的决定，该领域必须承认这些司法管辖区所面临的现实，讨论每种方法的利弊，并确定做出此类决定的框架。这篇新颖的论文回顾了现有文献，并确定了三个主要解决方案供考虑：1) 使用卫星实验室进行样本分流；2) 使用主要区域实验室进行全面法证分析；3) 警方使用快速 DNA 减少积压。除这些战略外，还考虑了成本和质量对每种所述方案的影响。虽然文献支持某些方法可以通过缩短周转时间来降低下游成本的说法，但在考虑这些方案时，用于支持决策的商业案例（包括使用成本效益分析或案例研究）的数据却很有限，这突出了本文的新颖性。这很可能是由于法医部门的商业化性质阻碍了私营实验室业务方法的公布。法医文献中缺乏对 "商业案例 "的强调可能会误导研发科学家，使他们在进行自己的研究时无法考虑这些因素。

{"title":"Improving the forensic genetic workflow for countries with small geographical areas: What are the options and how cost effective are they?","authors":"Anabella De La Chica , Jason Birkett , Cynthia Akwei , David Lamont , Nick Dawnay","doi":"10.1016/j.fsigen.2024.103171","DOIUrl":"10.1016/j.fsigen.2024.103171","url":null,"abstract":"<div><div>Forensic services worldwide often encounter considerable challenges relating to funding and infrastructure. Smaller jurisdictions or areas where forensic resources are scarce are faced with complicated choices in how they approach criminal casework, with a number of options available. Often these involve trade-offs between cost, time and data quality. Faced with such decisions it becomes important for the field to acknowledge the realities facing such jurisdictions, discuss the pros and cons of each approach, and identify a framework for making such decisions. This novel paper, reviews the available literature and identifies three main solutions for consideration: 1) the use of satellite laboratories for sample triage, 2) the use of a main regional laboratory for full forensic analysis and 3) the use of rapid DNA by police for reducing backlogs. Alongside these strategies, the impacts of cost and quality in regard to each of the stated options are considered. While the literature supports the assertion that some methods can reduce downstream costs via the reduction in turnaround times, there is limited data highlighting the business case used to support decision making when considering these options including the use of cost:benefit analyses or case studies, emphasizing the novelty of this paper. This is likely due to the commercialized nature of the forensic sector preventing the publication of a private laboratory’s business approach. The lack of emphasis on the ‘business case’ in forensic literature has the potential to mislead R&D scientists who may consequently fail to consider such factors when performing their own research.</div></div>","PeriodicalId":50435,"journal":{"name":"Forensic Science International-Genetics","volume":"74 ","pages":"Article 103171"},"PeriodicalIF":3.2,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142651500","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Salivary microbiome signatures of Poles and Serbians and its potential for prediction of biogeographic ancestry 波兰人和塞尔维亚人唾液微生物组特征及其预测生物地理祖先的潜力。

IF 3.2 2区医学 Q2 GENETICS & HEREDITY

Forensic Science International-Genetics

Pub Date : 2024-11-06 DOI: 10.1016/j.fsigen.2024.103173

Katarzyna Skonieczna , Natasa Kovacevic-Grujicic , Aashish Srivastava , Mariusz Gawrych , Marzanna Ciesielka , Nisha Rana , Danijela Drakulic , Marija Mojsin , Milena Milivojevic , Milena Stevanovic , Grzegorz Teresiński , Tomasz Grzybowski

Biogeographical ancestry analysis is valuable in forensic investigations, especially in missing person cases or crimes without eyewitnesses, as it helps to infer geographic origins from genetic markers. This approach enhances forensic efforts by providing essential clues for identifying individuals with limited direct evidence. Slavic-speaking populations are poorly distinguishable based on human genome variability. However, recent studies show that even populations with close biogeographic origin could be differentiated based on salivary microbiomes. Nevertheless, the salivary microbiomes of Slavs have not been characterized yet. Therefore, this study aimed to compare the composition of the salivary microbiomes of Western and Southern Slavs’ representatives. 16S rRNA libraries from salivary microbiomes of 40 Poles (Western Slavs) and 40 Serbians (Southern Slavs) were prepared via PCR and sequenced on the MiSeq FGx platform (Illumina), giving approximately 100,000 reads per sample. Bioinformatic and statistical analyses were performed to assess the alpha and beta diversity of microbiomes and determine the differences in the abundance of bacterial genera between the groups studied. Analyses of alpha (ACE, Chao1, Shannon, and Simpson) and beta (Jaccard and Bray-Curtis dissimilarity) diversities in the salivary microbiomes clearly distinguished between Poles and Serbians. Alpha and beta diversity metrics were significantly higher in the Serbian population. Fusobacterium, Lautropia, Porphyromonas, Actinobacillus, Capnocytophaga, and Kingella were the most significantly increased genera in Serbians, whereas Veillonella, Selenomonas, Megasphaera, and Atopobium were more prevalent in Poles. In summary, our study identified significant differences in the salivary microbiomes of Poles and Serbians, with distinct microbial signatures associated with each population. These findings highlight the potential of salivary microbiome analysis as a tool for predicting biogeographic ancestry. Nevertheless, further analysis extended to other Slavic-speaking populations is necessary to clarify this issue.

生物地理祖先分析在法医调查中很有价值，特别是在失踪人员案件或没有目击证人的犯罪案件中，因为它有助于从遗传标记推断地理起源。这种方法能在直接证据有限的情况下为确定个人身份提供重要线索，从而加强法医工作。根据人类基因组的变异性，讲斯拉夫语的人群很难区分。然而，最近的研究表明，即使是生物地理起源相近的人群也可以根据唾液微生物组进行区分。尽管如此，斯拉夫人唾液微生物组的特征尚未得到研究。因此，本研究旨在比较西方和南方斯拉夫人代表的唾液微生物组的组成。研究人员通过 PCR 从 40 个波兰人（西部斯拉夫人）和 40 个塞尔维亚人（南部斯拉夫人）的唾液微生物组中制备了 16S rRNA 文库，并在 MiSeq FGx 平台（Illumina）上进行了测序，每个样本可获得约 100,000 个读数。研究人员进行了生物信息学和统计学分析，以评估微生物组的α和β多样性，并确定研究群体之间细菌属丰度的差异。对唾液微生物组的α（ACE、Chao1、Shannon和Simpson）和β（Jaccard和Bray-Curtis相似性）多样性进行的分析明确区分了波兰人和塞尔维亚人。塞尔维亚人的α和β多样性指标明显更高。在塞尔维亚人中，Fusobacterium、Lautropia、Porphyromonas、Actinobacillus、Capnocytophaga 和 Kingella 是增加最明显的菌属，而在波兰人中，Veillonella、Selenomonas、Megasphaera 和 Atopobium 则更为普遍。总之，我们的研究发现了波兰人和塞尔维亚人唾液微生物组的显著差异，每个人群都有不同的微生物特征。这些发现凸显了唾液微生物组分析作为预测生物地理祖先的工具的潜力。不过，有必要对其他斯拉夫语人群进行进一步分析，以澄清这一问题。

{"title":"Salivary microbiome signatures of Poles and Serbians and its potential for prediction of biogeographic ancestry","authors":"Katarzyna Skonieczna , Natasa Kovacevic-Grujicic , Aashish Srivastava , Mariusz Gawrych , Marzanna Ciesielka , Nisha Rana , Danijela Drakulic , Marija Mojsin , Milena Milivojevic , Milena Stevanovic , Grzegorz Teresiński , Tomasz Grzybowski","doi":"10.1016/j.fsigen.2024.103173","DOIUrl":"10.1016/j.fsigen.2024.103173","url":null,"abstract":"<div><div>Biogeographical ancestry analysis is valuable in forensic investigations, especially in missing person cases or crimes without eyewitnesses, as it helps to infer geographic origins from genetic markers. This approach enhances forensic efforts by providing essential clues for identifying individuals with limited direct evidence. Slavic-speaking populations are poorly distinguishable based on human genome variability. However, recent studies show that even populations with close biogeographic origin could be differentiated based on salivary microbiomes. Nevertheless, the salivary microbiomes of Slavs have not been characterized yet. Therefore, this study aimed to compare the composition of the salivary microbiomes of Western and Southern Slavs’ representatives. 16S rRNA libraries from salivary microbiomes of 40 Poles (Western Slavs) and 40 Serbians (Southern Slavs) were prepared <em>via</em> PCR and sequenced on the MiSeq FGx platform (Illumina), giving approximately 100,000 reads per sample. Bioinformatic and statistical analyses were performed to assess the alpha and beta diversity of microbiomes and determine the differences in the abundance of bacterial genera between the groups studied. Analyses of alpha (ACE, Chao1, Shannon, and Simpson) and beta (Jaccard and Bray-Curtis dissimilarity) diversities in the salivary microbiomes clearly distinguished between Poles and Serbians. Alpha and beta diversity metrics were significantly higher in the Serbian population. <em>Fusobacterium, Lautropia, Porphyromonas, Actinobacillus, Capnocytophaga</em>, and <em>Kingella</em> were the most significantly increased genera in Serbians, whereas <em>Veillonella, Selenomonas, Megasphaera,</em> and <em>Atopobium</em> were more prevalent in Poles. In summary, our study identified significant differences in the salivary microbiomes of Poles and Serbians, with distinct microbial signatures associated with each population. These findings highlight the potential of salivary microbiome analysis as a tool for predicting biogeographic ancestry. Nevertheless, further analysis extended to other Slavic-speaking populations is necessary to clarify this issue.</div></div>","PeriodicalId":50435,"journal":{"name":"Forensic Science International-Genetics","volume":"74 ","pages":"Article 103173"},"PeriodicalIF":3.2,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142635067","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Research on correlation between DNA typing and trace characteristics of blood after thermal exposure 研究热暴露后 DNA 分型与血液微量特征之间的相关性。

IF 3.2 2区医学 Q2 GENETICS & HEREDITY

Forensic Science International-Genetics

Pub Date : 2024-11-05 DOI: 10.1016/j.fsigen.2024.103172

Junyi Di , Jing Jin , Jinzhuan Zhang , Xiaoning Xu , Chen Li , Keli Guo , Chaoyi Shi

The identification of biological evidence is particularly important for criminal detection, and the deoxyribonucleic acid (DNA) analysis plays a significant role in reconstructing events. However, bloodstains after thermal exposure in fires are quite unique compared to those in other scenes. Previous results regarding DNA recovery in bloodstains after heating are inconsistent with each other, which limits guidance for forensic science. In order to confirm the influence of heat on DNA recovery, the important physical evidence, bloodstain, was selected for its common occurrence, and a standard heat source, the Cone Calorimeter, was used to simulate high temperatures in fire scenes. A series of bloodstains were prepared under different heating conditions, and the results of short tandem repeat (STR) typing were systematically correlated with the trace characteristics of bloodstains. The findings indicate that heating bloodstains below 150 °C for less than 10 mins has minimal effect on DNA testing. After heating bloodstains at 150 °C for 20 mins or at 180 °C for 5 mins, partial DNA profiles were obtained, accompanied by blackening and cracking of the bloodstains. After exposure to 180 °C for 20 mins or 200 °C for 10 mins, no DNA profiles were obtained with bloodstains exhibiting metallic lusters and black bulges. Furthermore, from the perspective of chemical bond energy, the C-N, C-O, C-C, and P-O bonds in DNA molecules are prone to breaking during heating. The C-N bond serves as the primary connection between the four bases and the strand, while the C-O, C-C, and P-O bonds are significant connections within the DNA strand. It is thus hypothesized that the breakage of any bond aforementioned during heating results in the failure of DNA typing. Understanding the correlation between trace characteristics of bloodstains and DNA typing results after thermal exposure is crucial for comprehending DNA recovery from physical evidence collected from fire scenes.

生物证据的鉴定对于刑事侦查尤为重要，脱氧核糖核酸（DNA）分析在重建事件中发挥着重要作用。然而，与其他场景中的血迹相比，火灾中热辐射后的血迹非常独特。以往有关加热后血迹中 DNA 恢复的结果并不一致，这限制了对法医学的指导。为了证实加热对 DNA 复原的影响，我们选择了常见的重要物证--血迹，并使用标准热源锥形量热仪模拟火灾现场的高温。在不同的加热条件下制备了一系列血迹，并将短串联重复（STR）分型结果与血迹的痕迹特征进行了系统关联。研究结果表明，在 150 °C 以下加热血迹少于 10 分钟，对 DNA 检测的影响微乎其微。将血迹在 150 ℃ 下加热 20 分钟或 180 ℃ 下加热 5 分钟后，可获得部分 DNA 图谱，同时血迹会变黑和开裂。在 180 °C 下加热 20 分钟或 200 °C 下加热 10 分钟后，没有得到 DNA 图谱，血迹呈现金属光泽和黑色隆起。此外，从化学键能的角度来看，DNA 分子中的 C-N、C-O、C-C 和 P-O 键在加热过程中容易断裂。C-N 键是四个碱基和链之间的主要连接，而 C-O、C-C 和 P-O 键是 DNA 链内部的重要连接。因此，假设上述任何键在加热过程中断裂都会导致 DNA 分型失败。了解血迹的痕迹特征与热暴露后 DNA 分型结果之间的相关性，对于理解从火灾现场收集的物证中恢复 DNA 至关重要。

{"title":"Research on correlation between DNA typing and trace characteristics of blood after thermal exposure","authors":"Junyi Di , Jing Jin , Jinzhuan Zhang , Xiaoning Xu , Chen Li , Keli Guo , Chaoyi Shi","doi":"10.1016/j.fsigen.2024.103172","DOIUrl":"10.1016/j.fsigen.2024.103172","url":null,"abstract":"<div><div>The identification of biological evidence is particularly important for criminal detection, and the deoxyribonucleic acid (DNA) analysis plays a significant role in reconstructing events. However, bloodstains after thermal exposure in fires are quite unique compared to those in other scenes. Previous results regarding DNA recovery in bloodstains after heating are inconsistent with each other, which limits guidance for forensic science. In order to confirm the influence of heat on DNA recovery, the important physical evidence, bloodstain, was selected for its common occurrence, and a standard heat source, the Cone Calorimeter, was used to simulate high temperatures in fire scenes. A series of bloodstains were prepared under different heating conditions, and the results of short tandem repeat (STR) typing were systematically correlated with the trace characteristics of bloodstains. The findings indicate that heating bloodstains below 150 °C for less than 10 mins has minimal effect on DNA testing. After heating bloodstains at 150 °C for 20 mins or at 180 °C for 5 mins, partial DNA profiles were obtained, accompanied by blackening and cracking of the bloodstains. After exposure to 180 °C for 20 mins or 200 °C for 10 mins, no DNA profiles were obtained with bloodstains exhibiting metallic lusters and black bulges. Furthermore, from the perspective of chemical bond energy, the C-N, C-O, C-C, and P-O bonds in DNA molecules are prone to breaking during heating. The C-N bond serves as the primary connection between the four bases and the strand, while the C-O, C-C, and P-O bonds are significant connections within the DNA strand. It is thus hypothesized that the breakage of any bond aforementioned during heating results in the failure of DNA typing. Understanding the correlation between trace characteristics of bloodstains and DNA typing results after thermal exposure is crucial for comprehending DNA recovery from physical evidence collected from fire scenes.</div></div>","PeriodicalId":50435,"journal":{"name":"Forensic Science International-Genetics","volume":"74 ","pages":"Article 103172"},"PeriodicalIF":3.2,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142640229","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0