Next Generation Sequencing Plus (NGS+) with Y-chromosomal Markers for Forensic Pedigree Searches

Development and validation of YARN: A novel SE-400 MPS kit for East Asian paternal lineage analysis

Y-chromosomal short tandem repeat polymorphisms (Y-STRs) and Y-chromosomal single nucleotide polymorphisms (Y-SNPs) are valuable genetic markers used in paternal lineage identification and population genetics. Currently, there is a lack of an effective panel that integrates Y-STRs and Y-SNPs for studying paternal lineages, particularly in East Asian populations. Hence, we developed a novel Y-chromosomal targeted panel called YARN (Y-chromosome Ancestry and Region Network) based on multiplex PCR and a single-end 400 massive parallel sequencing (MPS) strategy, consisting of 44 patrilineage Y-STRs and 260 evolutionary Y-SNPs. A total of 386 reactions were validated for the effectiveness and applicability of YARN according to SWGDAM validation guidelines, including sensitivity (with a minimum input gDNA of 0.125 ng), mixture identification (ranging from 1:1-1:10), PCR inhibitor testing (using substances such as 50 μM hematin, 100 μM hemoglobin, 100 μM humic acid, and 2.5 mM indigo dye), species specificity (successfully distinguishing humans from other animals), repeatability study (achieved 100% accuracy), and concordance study (with 99.91% accuracy for 1121 Y-STR alleles). Furthermore, we conducted a pilot study using YARN in a cohort of 484 Han Chinese males from Huaiji County, Zhaoqing City, Guangdong, China (GDZQHJ cohort). In this cohort, we identified 52 different Y-haplogroups and 73 different surnames. We found weak to moderate correlations between the Y-haplogroups, Chinese surnames, and geographical locations of the GDZQHJ cohort (with λ values ranging from 0.050 to 0.340). However, when we combined two different categories into a new independent variable, we observed stronger correlations (with λ values ranging from 0.617 to 0.754). Overall, the YARN panel, which combines Y-STR and Y-SNP genetic markers, meets forensic DNA quality assurance guidelines and holds potential for East Asian geographical origin inference and paternal lineage analysis.

YHP: Y-chromosome Haplogroup Predictor for predicting male lineages based on Y-STRs

Human Y chromosome reflects the evolutionary process of males. Male lineage tracing by Y chromosome is of great use in evolutionary, forensic, and anthropological studies. Identifying the male lineage based on the specific distribution of Y haplogroups narrows down the investigation scope, which has been used in forensic scenarios. However, existing software aids in familial searching using Y-STRs (Y-chromosome short tandem repeats) to predict Y-SNP (Y-chromosome single nucleotide polymorphism) haplogroups, they often lack resolution. In this study, we developed YHP (Y Haplogroup Predictor), a novel software offering high-resolution haplogroup inference without requiring extensive Y-SNP sequencing. Leveraging existing datasets (219 haplogroups, 4064 samples in total), YHP predicts haplogroups with 0.923 accuracy under the highest haplogroup resolution, employing a random forest algorithm. YHP, available on Github (https://github.com/cissy123/YHP-Y-Haplogroup-Predictor-), facilitates high-resolution haplogroup prediction, haplotype mismatch analysis, and haplotype similarity comparison. Notably, it demonstrates efficacy in East Asian populations, benefiting from training data from eight distinct East Asian ethnic populations. Moreover, it enables seamless integration of additional training sets, extending its utility to diverse populations.

Developmental validation of a novel 8-dye fluorescent typing system with 59 Y-STRs and 3 Y-indels for forensic applications

An 8-dye fluorescence-labeling forensic Y-chromosomal short tandem repeats (Y-STRs) kit, the 62-plex Y-STR multiplex amplification system, was developed and optimized. The system was validated by testing PCR conditions, stutter ratios (SR) and peak height ratios, sensitivity, mixture samples, precision and accuracy, species-specificity, and inhibition studies according to the Scientific Working Group on DNA Analysis Methods guidelines. PCR-based studies showed that the recommended PCR conditions were optimized for this kit. In the sensitivity study, a full profile was obtained from template DNA with a quantity of u125 pg. Consistent profiles were obtained from three different laboratories. The SRs in all loci were less than 15%, and nice balance and suitable average peak height were shown. No peaks were detected in the profiles of common animal species and microorganisms. In the male-male mixture studies, all loci were observed at a ratio of 1:8, and in the male-female mixture study, all alleles could be profiled at a ratio of 1:500 if the male DNA inputs were ≥0.5 ng/µL. An inhibitor study demonstrated that the kit had varying degrees of resistance to the presence of common inhibitors. Population study demonstrated the 62-plex Y-STR Kit improved the power of discrimination in unrelated Chinese Han males (n = 192). When haplotype diversity was 1, the probability of discrimination power of the 62-plex Y-STR Kit was 0.9948, which is suitable for forensic investigations. The results show that the developed 8-dye fluorescence labeling 62 loci system is sensitive, robust, convenient, and highly informative for forensic applications.

Improving the strategy to identify historical military remains: a literature review and Y-STR meta-analysis

The identification of historical military remains by Unrecovered War Casualties-Army (UWC-A) currently relies on Y-chromosome Short Tandem Repeat (Y-STR) testing when maternal relatives are not available, or when a mitochondrial DNA match does not provide sufficient certainty of identification. However, common Y-STR profiles (using Yfiler™) between sets of remains or families often prevent identification. To resolve these cases, an investigation of additional Y-DNA markers is needed for their potential inclusion into the DNA identification strategy. The number of genetic transmissions between missing soldiers and their living relatives needs to be considered to avoid false exclusions between paternal relatives. Analysis of 236 World War I/II (WWI/II) era pairs of relatives identified up to seven genetic transmissions between WWII soldiers and their living relatives, and nine for WWI. Previous Y-STR meta-analyses were published approximately 10 years ago when rapidly mutating markers were relatively new. This paper reports a contemporary literature review and meta-analysis of 35 studies (which includes 23 studies not previously used in meta-analysis) and 23 commonly used Y-STR's mutation rates to inform the inclusion of additional loci to UWC-A's DNA identification strategy. Meta-analysis found mutation data for a given Y-STR locus could be pooled between studies and that the mutation rates were significantly different between some loci (at P < 0.05). Based on this meta-analysis, we have identified two additional markers from PowerPlex® Y23 for potential inclusion in UWC-A's identification strategy. Further avenues for potential experimental exploration are discussed.

Key points

From 236 UWC-A pairs of relatives, we observed up to nine genetic transmissions between WWI soldiers and their living relatives, and seven for WWII.MedCalc® software for meta-analysis utilizing the Freeman-Tukey transformation was run, which analysed 35 published studies and 23 commonly used loci. Previous Y-STR mutation rate meta-analyses are now 10 years old; this paper includes 23 studies that were not included in previous meta-analyses.Through meta-analysis, we identify two markers from PowerPlex® Y23 for potential inclusion in UWC-A's historical remains identification strategy (alongside Yfiler™). We discuss potential next steps for experimental exploration of additional Y-DNA markers.

Unraveling the paternal genetic structure and forensic traits of the Hui population in Liaoning Province, China using Y-chromosome analysis

The Hui people are the second-largest ethnic minority in China, and they are distributed throughout the country. A previous study explored the paternal genetic structure of the Hui population in nine different regions of China, but it overlooked the Liaoning province. In this study, we examined the paternal genetic makeup and forensic traits of the Hui population in Liaoning province by analyzing 157 Y-chromosome single nucleotide polymorphisms (Y-SNPs) and 26 short tandem repeats (Y-STRs). We successfully genotyped 282 unrelated male individuals from the Hui population of Liaoning province using the SNaPshot® single base extension assay and Goldeneye™ Y26 system kit (PEOPLESPOT R&D, Beijing, China). The results revealed high haplotypic diversity (0.9998) and identified 46 terminal haplogroups for the Hui population. Additional analyses, such as heat maps, principal component analysis (PCA), genetic distance (FST), Multidimensional scaling (MDS) analysis, and median-joining network (MJ) analysis, showed that the Hui population could be classified into three groups: Northwest Hui populations (NWH), including Liaoning, Xinjiang, Qinghai, Gansu, Ningxia, Shaanxi, and Henan; Hui populations from Sichuan and Shandong (SSH); and Yunnan Hui populations (YNH). Pairwise genetic distance (Rst) comparisons with other Chinese populations revealed that the Hui population displayed genetic affinity with the Han population. The comprehensive understanding of the Hui population in Liaoning province, explored by Y-SNPs and Y-STRs, can be utilized to interpret their genetic structure and enhance the accuracy of forensic databases.

Developmental validation of a 381 Y-chromosome SNP panel for haplogroup analysis in the Chinese populations

Y-chromosome single nucleotide polymorphism (Y-SNP) shows great variation in geographical distribution and population heterogeneity and can be used to map population genetics around the world. Massive parallel sequencing (MPS) methodology enables high-resolution Y-SNP haplogrouping for a certain male and is widely used in forensic genetics and evolutionary studies. In this present study, we used MPS to develop a customized 381 Y-SNP panel (SifaMPS 381 Y-SNP panel) to investigate the basic structure and subbranches of the haplogroup tree of the Chinese populations. The SifaMPS 381 Y-SNP panel covers all the Y-SNPs from our previously designed 183 Y-SNP panel and additional SNPs under the predominant haplogroups in the Chinese populations based on certain criteria. We also evaluated the sequencing matrix, concordance, sensitivity, repeatability of this panel and the ability to analyze mixed and case-type samples based on the Illumina MiSeq System. The results demonstrated that the novel MPS Y-SNP panel possessed good sequencing performance and generated accurate Y-SNP genotyping results. Although the recommended DNA input was greater than 1.25 ng, we observed that a lower DNA amount could still be used to analyze haplogroups correctly. In addition, this panel could handle mixed samples and common case-type samples and had higher resolution among Chinese Han males than previously reported. In conclusion, the SifaMPS 381 Y-SNP panel showed an overall good performance and offers a better choice for Y-SNP haplogrouping of the Chinese population, thereby facilitating paternal lineage classification, familial searching and other forensic applications.

Inference of population structure and admixture proportion from Y chromosomal data of Chinese population

In the past two decades, Y chromosome data has been generated for human population genetic studies. These Y chromosome datasets were produced with various testing methods and markers, thus difficult to combine them for a comprehensive analysis. In this study, we combine four human Y chromosomal datasets of Han, Tibetan, Hui, and Li ethnic groups. The dataset contains 27 microsatellites and 137 single nucleotide polymorphisms these populations share in common. We assembled a single dataset containing 2439 individuals from 25 nationwide populations in China. A systematic analysis of genetic distance and clustering was performed. To determine the gene flow of the studied population with worldwide populations, we modeled the ancestry informative markers. The reference panel was regarded as a mixture of South Asian (SAS), East Asian (EAS), European (EUR), African (AFR), and American (AMR) populations from 1000 Genomes data of Y chromosome using nonlinear data-fitting. We then calculated the admixture proportion of these four studied populations with 26 worldwide populations. The results showed that the Han and Hui have great genetic affinity, and Hui is the most admixed ethnic group, with 61.53% EAS, 34.65% SAS, 1.91% AFR, 1.56% AMR, and 0.04% EUR ancestry component (the AMR is highly admixed and thus should be ignored). All the other three ethnic groups contained more than 97% EAS ancestry component. The Li is the least admixed population in this study. The combined dataset in this study is the largest of this kind reported to date and proposes reference population data for use in future paternal genetic studies and forensic genealogical identification.

Development and validation of a new multiplex Y-STR panel designed to increase the power of discrimination

In an attempt to increase the discrimination capacity (DC) and reduce the adventitious match probability, a 6-dye multiplex Y-chromosomal short tandem repeat (Y-STR) panel named Y34plex was constructed that combined 25 Y-chromosomal markers (DYS456, DYS627, DYS390, DYS570, DYS635, DYS385a/b, DYS448, DYS437, DYS533, DYS449, DYS481, DYS392, DYS391, DYS389I, DYS460, YGATAH4, DYS438, DYS389II, DYS19, DYS458, DYF387S1a/b, DYS439, DYS393, DYS576, and DYS518) in widely used commercial kits, with nine highly polymorphic Y-STR loci (DYS557, DYS527a/b, DYS593, DYS444, DYS596, DYS643, DYS447, DYS549, and DYS645). The Y34plex is a promising type system to distinguish both unrelated and related male individuals due to the incorporation of rapidly mutated Y-STR loci. A validation study of the Y34plex was performed and followed the guidelines of the Scientific Working Group on DNA analysis methods. Results show that full Y-STR profiles were obtained from male/female DNA mixtures with 125 pg of male DNA in the presence of 50 ng of female DNA. The ability to tolerate polymerase chain reaction inhibitors commonly contained in forensic casework samples demonstrated the applicability and robustness of the Y34plex. Compared with the Yfiler Plus kit, the novel panel showed an increased power of discrimination in Chinese Wuxi Han population (n = 434). The overall haplotype diversity of the Y34plex was 0.999606, whereas DC value was 0.956221, which is suitable for use on forensic paternal investigation.

Improving DNA Data Capacity: Forensic Parameters and Genetic Structure Analysis of Jinjiang Han Population with the Microreader™ Y Prime Plus ID System

OBJECTIVE

Population genetic analysis based on genetic markers harbors valuable forensic applications. In this regard, it is informative and imperative to explore Han groups as they are the largest population of China. In particular, there is a largely underrepresented amount of information from recent decades regarding the southeast costal Han Chinese. Therefore, the aim of this study is to investigate the available genetic characteristics of the Han population living in the Jinjiang, Fujian Province, Southeastern China.

METHODS

We sampled 858 saliva samples and used the commercially available Microreader™ Y Prime Plus ID System to identify population data of Y-short tandem repeat (STR) loci of this region.

RESULTS

A total of 822 different haplotypes were observed. The overall haplotype diversity, discriminatory power and haplotype match probability were 0.9999, 0.9999 and 0.0012, respectively.

CONCLUSION

Our results showed that the Jinjiang Han population was closely genetically related to Han groups of China. Overall, we identified a set of 37 Y-STRs that are highly polymorphic, and that can provide meaningful information in forensic practice and human genetic research.

Improving the regional Y-STR haplotype resolution utilizing haplogroup-determining Y-SNPs and the application of machine learning in Y-SNP haplogroup prediction in a forensic Y-STR database: A pilot study on male Chinese Yunnan Zhaoyang Han population

Improving the resolution of the current widely used Y-chromosomal short tandem repeat (Y-STR) dataset is of great importance for forensic investigators, and the current approach is limited, except for the addition of more Y-STR loci. In this research, a regional Y-DNA database was investigated to improve the Y-STR haplotype resolution utilizing a Y-SNP Pedigree Tagging System that includes 24 Y-chromosomal single nucleotide polymorphism (Y-SNP) loci. This pilot study was conducted in the Chinese Yunnan Zhaoyang Han population, and 3473 unrelated male individuals were enrolled. Based on data on the male haplogroups under different panels, the matched or near-matching (NM) Y-STR haplotype pairs from different haplogroups indicated the critical roles of haplogroups in improving the regional Y-STR haplotype resolution. A classic median-joining network analysis was performed using Y-STR or Y-STR/Y-SNP data to reconstruct population substructures, which revealed the ability of Y-SNPs to correct misclassifications from Y-STRs. Additionally, population substructures were reconstructed using multiple unsupervised or supervised dimensionality reduction methods, which indicated the potential of Y-STR haplotypes in predicting Y-SNP haplogroups. Haplogroup prediction models were built based on nine publicly accessible machine-learning (ML) approaches. The results showed that the best prediction accuracy score could reach 99.71% for major haplogroups and 98.54% for detailed haplogroups. Potential influences on prediction accuracy were assessed by adjusting the Y-STR locus numbers, selecting Y-STR loci with various mutabilities, and performing data processing. ML-based predictors generally presented a better prediction accuracy than two available predictors (Nevgen and EA-YPredictor). Three tree models were developed based on the Yfiler Plus panel with unprocessed input data, which showed their strong generalization ability in classifying various Chinese Han subgroups (validation dataset). In conclusion, this study revealed the significance and application prospects of Y-SNP haplogroups in improving regional Y-STR databases. Y-SNP haplogroups can be used to discriminate NM Y-STR haplotype pairs, and it is important for forensic Y-STR databases to develop haplogroup prediction tools to improve the accuracy of biogeographic ancestry inferences.

CSYseq: The first Y-chromosome sequencing tool typing a large number of Y-SNPs and Y-STRs to unravel worldwide human population genetics

Male-specific Y-chromosome (chrY) polymorphisms are interesting components of the DNA for population genetics. While single nucleotide polymorphisms (Y-SNPs) indicate distant evolutionary ancestry, short tandem repeats (Y-STRs) are able to identify close familial kinships. Detailed chrY analysis provides thus both biogeographical background information as paternal lineage identification. The rapid advancement of high-throughput massive parallel sequencing (MPS) technology in the past decade has revolutionized genetic research. Using MPS, single-base information of both Y-SNPs as Y-STRs can be analyzed in a single assay typing multiple samples at once. In this study, we present the first extensive chrY-specific targeted resequencing panel, the ‘CSYseq’, which simultaneously identifies slow mutating Y-SNPs as evolution markers and rapid mutating Y-STRs as patrilineage markers. The panel was validated by paired-end sequencing of 130 males, distributed over 65 deep-rooted pedigrees covering 1,279 generations. The CSYseq successfully targets 15,611 Y-SNPs including 9,014 phylogenetic informative Y-SNPs to identify 1,443 human evolutionary Y-subhaplogroup lineages worldwide. In addition, the CSYseq properly targets 202 Y-STRs, including 81 slow, 68 moderate, 27 fast and 26 rapid mutating Y-STRs to individualize close paternal relatives. The targeted chrY markers cover a high average number of reads (Y-SNP = 717, Y-STR = 150), easy interpretation, powerful discrimination capacity and chrY specificity. The CSYseq is interesting for research on different time scales: to identify evolutionary ancestry, to find distant family and to discriminate closely related males. Therefore, this panel serves as a unique tool valuable for a wide range of genetic-genealogical applications in interdisciplinary research within evolutionary, population, molecular, medical and forensic genetics.

Around 95% of the male-specific Y-chromosome (chrY) is non-recombining and therefore inherited in a conserved manner from father to son. It can therefore serve as a powerful marker for interdisciplinary genetic-genealogical research as it provides a strong link between genetic information and a family tree or pedigree. While Y-chromosomal short tandem repeats (Y-STRs) discriminate close paternal kinships, single nucleotide polymorphisms (Y-SNPs) enables the identification of far evolutionary ancestry. Unfortunately, an extensive chrY-specific sequencing panel combining a large number of familial Y-STRs and evolutionary Y-SNPs was not yet available. Therefore, chrY is rarely included in research projects and not often linked to a genealogical, history-demographical or life science database. In this way, the importance of chrY still remains not yet fully understood. Massive parallel sequencing (MPS) allows the simultaneous analysis at sequence level of Y-SNPs and Y-STRs with variable mutation rates in a large number of males. However, up until today, no commercial kit is exploiting the full potential that MPS offers on chrY. Therefore, we developed the ‘CSYseq’, which is the first extensive chrY-specific sequencing panel. The CSYseq simultaneously identifies 9,014 slow mutating Y-SNPs to identify evolutionary ancestry, and 202 rapid mutating Y-STRs to investigate paternal relationships. We validated and optimized the panel through the analysis of 130 males distributed over 65 families. This novel MPS panel is useful for biogeographical identity and ancestry analysis, together with Y-chromosome profiling for the identification of patrilineages and discrimination of closely related males. As the CSYseq includes a very diverse set of markers that can be easily interpreted, it is interesting for different interdisciplinary applications within evolutionary, population, molecular, medical and forensic genetics.

BGISEQ-500RS sequencing of a 448-plex SNP panel for forensic individual identification and kinship analysis

Next generation sequencing (NGS)-based single nucleotide polymorphism (SNP) genotyping is widely used in the field of forensics. SNP genotyping data from several NGS platforms have been published, but forensic application trials of DNA nanoball sequencing platforms have been very limited. In this work, we developed a 448-plex SNP panel on the BGISEQ-500RS platform. The sequencing metrics of a total of 261 samples that were sequenced with this panel are reported in detail. The average sequencing depth was 8373 × and the average heterozygosity of the 448-plex assay was 0.85. Sensitivity analysis showed that 325 SNPs were successfully genotyped with as little as 50 pg of genomic DNA, with the mean quality score of the sequencing data above Q30. Forensic parameters were calculated based on the data of 142 unrelated Chinese Han individuals and the combined matching probability was as low as 5.21 × 10^-101. Kinship analyses based on experiments and computer simulations showed that the 448-panel was as effective as the ForenSeq™ DNA Signature Prep Kit for second-degree kinship identification, and when the two panels were merged, the related pairs were almost completely distinguished from unrelated pairs. The 448-plex SNP panel on the BGISEQ-500RS platform provides a powerful tool for forensic individual identification and kinship analysis.

Genetic insights into the paternal admixture history of Chinese Mongolians via high-resolution customized Y-SNP SNaPshot panels

The Mongolian people, one of the Mongolic-speaking populations, are native to the Mongolian Plateau in North China and southern Siberia. Many ancient DNA studies recently reported extensive population transformations during the Paleolithic to historic periods in this region, while little is known about the paternal genetic legacy of modern geographically different Mongolians. Here, we genotyped 215 Y-chromosomal single nucleotide polymorphisms (Y-SNPs) and 37 Y-chromosomal short tandem repeats (Y-STRs) among 679 Mongolian individuals from Hohhot, Hulunbuir, and Ordos in North China using the AGCU Y37 kit and our developed eight Y-SNP SNaPshot panels (including two panels first reported herein). The C-M130 Y-SNP SNaPshot panel defines 28 subhaplogroups, and the N/O/Q complementary Y-SNP SNaPshot panel defines 30 subhaplogroups of N1b-F2930, N1a1a1a1a3-B197, Q-M242, and O2a2b1a1a1a4a-CTS4658, which improved the resolution our developed Y-SNP SNaPshot panel set and could be applied for dissecting the finer-scale paternal lineages of Mongolic speakers. We found a strong association between Mongolian-prevailing haplogroups and some observed microvariants among the newly generated Y-STR haplotype data, suggesting the possibility of haplogroup prediction based on the distribution of Y-STR haplotypes. We identified three main ancestral sources of the observed Mongolian-dominant haplogroups, including the local lineage of C2*-M217 and incoming lineages from other regions of southern East Asia (O2*-M122, O1b*-P31, and N1*-CTS3750) and western Eurasia (R1*-M173). We also observed DE-M145, D1*-M174, C1*-F3393, G*-M201, I-M170, J*-M304, L-M20, O1a*-M119, and Q*-M242 at relatively low frequencies (< 5.00%), suggesting a complex admixture history between Mongolians and other incoming Eurasians from surrounding regions. Genetic clustering analyses indicated that the studied Mongolians showed close genetic affinities with other Altaic-speaking populations and Sinitic-speaking Hui people. The Y-SNP haplotype/haplogroup-based genetic legacy not only revealed that the stratification among geographically/linguistically/ethnically different Chinese populations was highly consistent with the geographical division and language classification, but also demonstrated that patrilineal genetic materials could provide fine-scale genetic structures among geographically different Mongolian people, suggesting that our developed high-resolution Y-SNP SNaPshot panels have the potential for forensic pedigree searches and biogeographical ancestry inference.

Genetic reconstruction and phylogenetic analysis by 193 Y-SNPs and 27 Y-STRs in a Chinese Yi ethnic group

Yi is the seventh-largest ethnic group in China and features mountainous regional characteristics. The Liangshan Yi Autonomous Prefecture is the largest Yi agglomeration with isolated geographical conditions, profoundly impeding genetic communication. Here, we investigated 427 unrelated males of Liangshan from 193 Y-chromosome single nucleotide polymorphisms (Y-SNPs) and 27 Y-chromosome short tandem repeats (Y-STRs) to reveal the genetic structure and paternal phylogeny of the group. The haplogroup diversity reached 0.9169 with 46 different subhaplogroups by 193 Y-SNPs, and the haplotype diversity reached 0.9999 by 27 Y-STR loci. Multidimensional scaling (MDS), N-J tree, and Network were constructed to decipher and visualize the genetic relations between Yi and worldwide groups. Our results revealed: (1) the Network by Y-STRs and Y-SNPs showed the haplogroup D1a1a-M15 in the Liangshan Yi population was a ramification of Tibetan groups' expansion from west to east on the plateau; (2) the haplogroup distribution and the mismatch mutation analysis indicated the haplogroup O2a2b1a1a1a4a2-Z25929 of Liangshan Yi derived from manifold Southeast Asian immigrants; (3) a high-resolution Y-SNPs panel is vital to depict accurate paternal derivations and build an integrated and refining genetic structure of ethnic groups.

Development and validation of a custom panel including 183 Y-SNPs for Chinese Y-chromosomal haplogroups dissection using a MALDI-TOF MS system

Y-chromosome SNP haplogroups exhibit geographic structuring in many populations around the world. Therefore, Y-chromosome haplogroups have been widely used to infer paternal biogeographical ancestry and high-resolution paternal lineage classification. In the present study, we designed a customized panel containing 183 Y-SNPs based on previous studies and evaluated the genotyping performance and repeatability, concordance, sensitivity, and ability of analysing case-type samples using a MALDI-TOF MS platform. The average call rate for duplicate typing of any one SNP in the panel was 97.0%. In the concordance and accuracy study, the results of haplogroup designation obtained from MALDI-TOF MS platform were fully consistent with those obtained from the next-generation sequencing (NGS) platform. The optimal amount of template DNA in the PCR seemed to be 10 ng. However, if less DNA (≥156.25 pg) was available, it was still possible to obtain meaningful haplogroup information. For the application part, this panel could be applied for the detection of blood, semen, and buccal swabs samples. Particularly, blood stain on FTA card samples could be dissected by direct PCR amplification on the MALDI-TOF MS platform. Besides, 371 unrelated male individuals from four Chinese ethnic groups (Han, Hui, Mongolian, and Kazak) were detected using this panel. Total 78 terminal haplogroups were found and the haplogroup diversity was 0.933576. The results demonstrate that this panel could be an accurate, fast, and cost-effective method for database construction where the amount of sample material is less of a concern and when the cost of the assay is taken into consideration.

Is MPS always the answer? Use of two PCR-based methods for Y-chromosomal haplotyping in highly and moderately degraded bone material

Forensic and population genetics often rely on Y-chromosomal studies. Whether it is a human identification case, trace evidence examination or phylogenetic analysis, a Y-STR haplotype is an important tool in the hands of law enforcement agencies. A common obstacle in achieving satisfactory results in all of the above mentioned circumstances, is low DNA quantity and quality within samples obtained. In this study we have examined Y-STR haplotypes in 75 bone material samples, coming from different time periods. For this purpose we have chosen YFiler Plus PCR Amplification Kit (ThermoFisher Scientific) and ForenSeq Signature DNA Prep Kit (Verogen Inc.), which use two different allele calling technologies - capillary electrophoresis and Massively Parallel Sequencing respectively. Full profiles were obtained from DNA extracts with as little as 0.1896 ng (Degradation Index 1.3) (ForenSeq) and 0.0591 ng (Degradation Index 26.8) (YFiler Plus) DNA input. The results that we present in this paper show differences in amplification rates between common markers in both kits. The differences strictly reflect mean amplicon length of markers. This, however, does not seem to influence Y-haplogroup estimation results noticeably. In one sample a discordance occurred between haplotypes obtained with both methods, where a 24 allele was called in DYS390 marker by capillary electrophoresis, while for the same sample in this locus a 23 allele was shown with MPS. A reason for this is yet to be investigated. The sequence analysis revealed a significant variation between isometric alleles, especially within repetitive regions of studied Y-STR markers.

Forensic characteristics and genetic analysis of both 27 Y-STRs and 143 Y-SNPs in Eastern Han Chinese population

Y-chromosome short tandem repeat (Y-STR) and Y-chromosome single nucleotide polymorphism (Y-SNP) frequency distributions provide resources for assessment of male population stratification among world-wide populations. Currently, the Y-STR Haplotype Reference Database (YHRD) contains numerous Y-chromosome haplotype profiles from various populations and countries around the world. However, for many of the recently discovered and already phylogenetically mapped Y-SNPs, the population data are scarce. Herein, the typing of 27 Y-STRs (Yfiler Plus) and 143 Y-SNPs (self-designed Y-SNP panel) was performed on 1269 unrelated males from 11 Han Chinese populations. Haplogroup O-M175 was the most predominant haplogroup in our Han Chinese data, ranging from 67.34% (Henan Han) to 93.16% (Guangdong Han). The highest haplogroup diversity (0.967056) was observed in Heilongjiang Han, with a discrimination capacity (DC) value of 0.3723. The number of alleles at single-copy loci varied from 2 for DYS391 (Guangdong Han) to 16 for DYS518 (Henan Han). For the majority of the populations (8/11), both the haplotype diversity and DC values are 1.0000. Furthermore, genetic differentiations were observed between Northern and Southern Han Chinese. These genetic differences were mainly reflected in haplogroup distribution and frequency, and they were confirmed by statistical analysis.

Prediction of Y haplogroup by polymerase chain reaction-reverse blot hybridization assay

BACKGROUND

The analysis of Y-SNPs from crime scene samples is helpful for investigators in narrowing down suspects by predicting biogeographical ancestry.

OBJECTIVE

In this study, a PCR-reverse blot hybridization assay (REBA) for predicting Y-chromosome haplogroups was employed to determine the major haplogroups worldwide, including AB, DE, C, C3, F, K, NO, O, O2, and O3 and evaluated.

METHODS

The REBA detects nine biallelic Y chromosome markers (M9, M89, M122, M145, M175, M214, M217, P31, and RPS4Y₇₁₁) simultaneously using multiple probes.

RESULTS

The REBA for Y-single nucleotide polymorphisms (SNP) genotyping was performed using 40 DNA samples from Asians-14 Koreans, 10 Indonesians, six Chineses, six Thais, and four Mongolians. 40 Asian samples were identified as haplogroup O2 (40%), O3 (32.5%), C3 (17.5%), O (7.5%) and K (2.5%). These cases were confirmed by DNA sequence analysis (κ = 1.00; P < 0.001).

CONCLUSION

PCR-REBA is a rapid and reliable method that complements other SNP detection methods. Therefore, implementing REBA for Y-SNP testing may be a useful tool in predicting Y-chromosome haplogroups.