A set of autosomal multiple InDel markers for forensic application and population genetic analysis in the Chinese Xinjiang Hui group

Genetic variation and phylogenetic analysis of 23 STR in Chinese Han population from Hainan, Southern China

The forensic characteristics and genetic relationships of Hainan Han population are still not fully understood. The aim of this study was to investigate the forensic features and genetic variations of 23 short tandem repeat (STR) included in the HuaxiaTM Platinum system in Hainan Han and analyze the population genetic relationships between Hainan Han and other adjacent Chinese populations. The genetic polymorphisms of 23 STR loci included in the HuaxiaTM Platinum kit were evaluated from 2971 Hainan Han individuals. Comprehensive comparisons were conducted based on genetic distance, phylogenetic tree, multidimensional scaling and principal component analysis (PCA) to explore inter-population genetic relationship. The combined power of discrimination (CPD) and the combined power of exclusion (CPE) of the 23 STR loci was 0.999 999 999 999 999 999 999 999 999 819 and 0.999 999 999 625 408, respectively. The investigated Hainan Han population has high genetic similarity with geographically close Han populations, while great genetic difference with other ethnic minorities, prominently in Yunnan Miao, Xinjiang Uygurs, Xinjiang Kazakh, and Tibetans. Our study found the 23 STR loci were highly polymorphic and suitable for forensic personal identification and paternity testing in Hainan Han population. Genetic similarity widely existed among Han populations from different regions, and significant genetic divergence existed between Han populations and some ethnic minorities. The populations genetic diversity and similarity were closely associated with ethnic origin and geographical distribution.

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.

Unveiling the genetic landscape of high-altitude adaptive ethnic groups with polymorphic markers: Implications of comprehensive forensic appraisals and population genetic investigations

Background

Deletion/insertion polymorphisms (DIPs), a novel class of biomarker, have been widely utilized in forensic areas for individual identification, paternity tests, and ancestral origin inference due to its applicability to degraded samples and low mutation rates. Despite the availability of a well-established commercial kit, the Investigator® DIPplex kit (Qiagen), certain loci exhibit limited levels of polymorphisms in East Asian populations, particularly in Chinese populations.

Objective

This dissertation seeks to undertake a comprehensive evaluation about the forensic efficiency of a self-developed multiplex amplification system in high-altitude adaptive ethnic groups of China. Healthy unrelated Tibetan individuals residing in Tibet Autonomous Region and Qinghai Province were genotyped using previously reported 43 deletion/insertion polymorphism loci. Forensic statistical analyses including allele frequencies and forensic parameters were conducted in the two Tibetan groups, and the genetic relatedness of the studied groups with reference populations from the 1000 Genomes Project Phase 3 were investigated.

Results

Forensic statistical results showed that the polymorphism information content values of the 43 deletion/insertion polymorphism loci in the two Tibetan groups exceeded 0.35. Moreover, the combined power of discrimination using the 43 deletion/insertion polymorphism loci was calculated to be 0.9999999999999999984 in the Qinghai Tibetan group and 0.9999999999999999921 in the Tibet Tibetan group. The cumulative power of exclusion using the 43 deletion/insertion polymorphism loci was calculated to be 0.999782512 in the Qinghai Tibetan group and 0.999886205 in the Tibet Tibetan group. Analysis of population genetics demonstrated that the two studied Tibetan groups shared close genetic relationships with East Asia populations.

Conclusion

The set of 43 deletion/insertion polymorphism loci exhibited remarkable forensic efficacy, rendering it a promising tool for forensic practice. Population genetic analyses indicated that the two Tibetan groups had closer genetic affinities to East Asian populations.

The infertile individual analysis based on whole-exome sequencing in chinese multi-ethnic groups

BACKGROUND

Infertility is a common and rapidly growing health issue around the world. The genetic analysis based on the infertile population is crucial for intervention and treatment.

OBJECTIVE

To find candidate gene locus led to azoospermia in Chinese multi-ethnic groups and provide theoretical guidance for the diagnosis of genetic diseases to progressively aggravated infertility patients and sterile offspring with ART.

METHODS

The study based on whole-exome sequencing (WES) was presented for genetic characteristic analysis of multi-ethnics and identification of variants related to infertility in Xinjiang area of China.

RESULTS

The frequency of pathogenic variants showed significant ethnic differences among four main ethnics in Xinjiang. The population structure analysis confirmed that the Hui was close to the Han population, the Kazak was close to the Uygur population, and there are three ancestry components in the four ethnics. In addition, ten candidate variants potentially regulated azoospermia were detected, and KNTC1 (rs7968222: G > T) was chosen to validate the association. Through the analysis in the valid group, the frequency of rs7968222 (G > T) has a significant difference in the azoospermia population (11.76%, 8/68) and normospermia population (4.63%, 35/756) (P < 0.001). Interestingly, the proportion of people with abnormal follicle-stimulating hormone (FSH) level in the group carrying rs7968222 (G > T) was significantly higher than non-carriers (P < 0.05). Therefore, rs7968222 may regulate spermatogenesis through affecting hormone level.

CONCLUSION

Our study establishes the genetics analysis of Northwest China and finds a candidate gene locus KNTC1 (rs7968222: G > T), which is one of the genetic susceptibility factors for male azoospermia.

Systematically exploring the performance of a self-developed Multi-InDel system in forensic identification, ancestry inference and genetic structure analysis of Chinese Manchu and Mongolian groups

The insertion/deletion (InDel) polymorphism has promising applications in forensic DNA analysis. However, the insufficient forensic efficiencies of the present InDel-based systems restrict their applications in parentage testing, due to the lower genetic polymorphism of the biallelic InDel locus and the limited number of InDel loci in a multiplex amplification system. Here, we introduced an in-house developed system which contained 41 polymorphic Multi-InDel markers (equivalent to 82 InDels in total), to serve as an efficient and reliable tool for different forensic applications in the Manchu and Mongolian groups. We demonstrated that the new system exhibited potential efficiencies for personal identification, parentage testing, two-person DNA mixture interpretation and ancestry inference of intercontinental populations. Meanwhile, we explored the genetic backgrounds of the Manchu and Mongolian groups by conducting a series of population genetic analyses. We showed that the Manchu and Mongolian groups shared closer genetic relationships with East Asian populations, especially Han Chinese populations in northern China. Moreover, more similar genetic compositions were detected between the Manchu group and the northern Han populations in this study, suggesting that the Manchu group had higher genetic affinities with northern Han populations than the Mongolian group. Overall. this study provided the necessary evidence that these Multi-InDel genetic markers could play an important role in forensic applications.

Forensic efficiency evaluation of a novel multiplex panel of InDels and STRs in the Guizhou Han population and its phylogenetic relationships with other reference populations

BACKGROUND

Insertion/deletion polymorphism (InDel), as the third genetic marker, has been given a lot of attention by forensic geneticists since it has the advantages of extensive distributions in the human genome, small amplicon, and low mutation rate. However, the extant InDel panels were only viewed as supplemental tools for kinship analyses. In addition, these panels were not conductive to mixture deconvolution because InDels in these panels mainly displayed two alleles.

AIMS

The purpose of this study is to investigate genetic distributions of a novel panel of InDels and STRs in the Guizhou Han population; assess the forensic application value of the panel; and conduct population genetic analyses of the Guizhou Han and other reference populations based on the overlapping loci.

SUBJECTS AND METHODS

The bloodstain samples of 209 Guizhou Han were gathered and genotyped by the novel panel. Allelic frequencies and forensic parameters of two miniSTRs and 59 InDels in the panel were estimated. In addition, we assessed phylogenetic relationships among the Guizhou Han and other reference populations by principal component analysis, D_A genetic distance, and neighbor-joining tree.

RESULTS

A total of 139 alleles of 61 loci could be observed in the Guizhou Han population. Polymorphic information content values of 59 InDels were greater than 0.3 in the Guizhou Han population. The cumulative power of discrimination and probability of exclusion of two miniSTRs and 59 InDels in the Guizhou Han population were 0.999999999999999999999999997984 and 0.9999986, respectively. Principal component analysis of 14 populations showed that the Guizhou Han population located closer to Hunan Han and Southern Han Chinese (CHS) populations. Similar results were also discerned from D_A genetic distances and the neighbor-joining tree.

CONCLUSION

To sum up, the novel panel could be employed for forensic personal identification and paternity testing in the Guizhou Han population as a promising independent tool. Besides, the principal component analysis and phylogenetic tree of the Guizhou Han and other compared populations revealed that the Guizhou Han population possesses close genetic affinities with Hunan Han, CHS, and Han Chinese in Beijing (CHB) populations.

Performance evaluation of an in-house panel containing 59 autosomal InDels for forensic identification in Chinese Hui and Mongolian groups

In recent years, a novel multiplex system containing two mini-short tandem repeats, 59 autosomal InDels, two Y-chromosomal InDels, and the Amelogenin gene with all amplicons less than 200 bp has been constructed and validated by ourselves for forensic degration sample, and its forensic application efficiency has been studied in Chinese some populations. Herein, the population genetic polymorphisms of these loci were investigated in Chinese Hui (n = 249) and Mongolian (n = 222) ethnic groups using direct multiplex amplification and capillary electrophoresis platform. The forensic identification efficiencies of this self-developed system were further evaluated in these two groups. And the results showed that the values of the combined power of discrimination were 0.9999999999999999999999999999006 (Hui) and 0.999999999999999999999999999738 (Mongolian), respectively. Moreover, the combined power of exclusion values were 0.99999817 (Hui) and 0.99999779 (Mongolian). The 59 autosomal InDels used in this study exhibited high forensic identification efficiencies in 10 East Asian populations, which was also expected to be a new powerful tool for identifying degraded biological materials in East Asian populations.

Systematic Evaluation of a Novel 6-dye Direct and Multiplex PCR-CE-Based InDel Typing System for Forensic Purposes

Insertion/deletion (InDel) polymorphisms, combined desirable characteristics of both short tandem repeats (STRs) and single nucleotide polymorphisms (SNPs), are considerable potential in the fields of forensic practices and population genetics. However, most commercial InDel kits designed based on non-Asians limited extensive forensic applications in East Asian (EAS) populations. Recently, a novel 6-dye direct and multiplex PCR-CE-based typing system was designed on the basis of genome-wide EAS population data, which could amplify 60 molecular genetic markers, consisting of 57 autosomal InDels (A-InDels), 2 Y-chromosomal InDels (Y-InDels), and Amelogenin in a single PCR reaction and detect by capillary electrophoresis, simultaneously. In the present study, the DNA profiles of 279 unrelated individuals from the Hainan Li group were generated by the novel typing system. In addition, we collected two A-InDel sets to evaluate the forensic performances of the novel system in the 1,000 Genomes Project (1KG) populations and Hainan Li group. For the Universal A-InDel set (UAIS, containing 44 A-InDels) the cumulative power of discrimination (CPD) ranged from 1-1.03 × 10-14 to 1-1.27 × 10-18, and the cumulative power of exclusion (CPE) varied from 0.993634 to 0.999908 in the 1KG populations. For the East Asia-based A-InDel set (EAIS, containing 57 A-InDels) the CPD spanned from 1-1.32 × 10-23 to 1-9.42 × 10-24, and the CPE ranged from 0.999965 to 0.999997. In the Hainan Li group, the average heterozygote (He) was 0.4666 (0.2366-0.5448), and the polymorphism information content (PIC) spanned from 0.2116 to 0.3750 (mean PIC: 0.3563 ± 0.0291). In total, the CPD and CPE of 57 A-InDels were 1-1.32 × 10-23 and 0.999965, respectively. Consequently, the novel 6-dye direct and multiplex PCR-CE-based typing system could be considered as the reliable and robust tool for human identification and intercontinental population differentiation, and supplied additional information for kinship analysis in the 1KG populations and Hainan Li group.

Development a multiplex panel of AISNPs, multi-allelic InDels, microhaplotypes and Y-SNP/InDel loci for multiple forensic purposes via the NGS

Recently, next generation sequencing showed the promising application value in forensic research. In this study, we constructed a multiplex system of different molecular genetic markers based on the previous selected AISNPs, multi-allelic InDels, microhaplotypes and Y-SNP/InDel loci and evaluated forensic efficiencies of the system in Chinese Shaanxi Han, Hui and Mongolian groups via the NGS platform. Ancestry informative analyses of Shaanxi Han, Hui and Mongolian groups revealed that most Mongolian individuals could be differentiated from Shaanxi Hans and Huis based on the selected AISNPs. Multi-allelic InDels and microhaplotypes showed the multiple allele variations and possessed relatively high genetic polymorphisms in these three groups, indicating these loci could also provide higher forensic efficiencies for individual identification and paternity testing. Based on Y-SNPs, different haplogroup distributions were observed among Shaanxi Han, Hui and Mongolian groups. In conclusion, the self-developed system could be used to simultaneously carry out the individual identification, paternity analysis, mixture deconvolution, forensic ancestry information analysis and Y chromosomal haplogroup inference, which could provide more investigative clues in forensic practices. This article is protected by copyright. All rights reserved.

Comprehensive Insights Into Forensic Features and Genetic Background of Chinese Northwest Hui Group Using Six Distinct Categories of 231 Molecular Markers

The Hui minority is predominantly composed of Chinese-speaking Islamic adherents distributed throughout China, of which the individuals are mainly concentrated in Northwest China. In the present study, we employed the length and sequence polymorphisms-based typing system of 231 molecular markers, i.e., amelogenin, 22 phenotypic-informative single nucleotide polymorphisms (PISNPs), 94 identity-informative single nucleotide polymorphisms (IISNPs), 24 Y-chromosomal short tandem repeats (Y-STRs), 56 ancestry-informative single nucleotide polymorphisms (AISNPs), 7 X-chromosomal short tandem repeats (X-STRs), and 27 autosomal short tandem repeats (A-STRs), into 90 unrelated male individuals from the Chinese Northwest Hui group to comprehensively explore its forensic characteristics and genetic background. Total of 451 length-based and 652 sequence-based distinct alleles were identified from 58 short tandem repeats (STRs) in 90 unrelated Northwest Hui individuals, denoting that the sequence-based genetic markers could pronouncedly provide more genetic information than length-based markers. The forensic characteristics and efficiencies of STRs and IISNPs were estimated, both of which externalized high polymorphisms in the Northwest Hui group and could be further utilized in forensic investigations. No significant departure from the Hardy-Weinberg equilibrium (HWE) expectation was observed after the Bonferroni correction. Additionally, four group sets of reference population data were exploited to dissect the genetic background of the Northwest Hui group separately from different perspectives, which contained 26 populations for 93 IISNPs, 58 populations for 17 Y-STRs, 26 populations for 55 AISNPs (raw data), and 109 populations for 55 AISNPs (allele frequencies). As a result, the analyses based on the Y-STRs indicated that the Northwest Hui group primarily exhibited intimate genetic relationships with reference Hui groups from Chinese different regions except for the Sichuan Hui group and secondarily displayed close genetic relationships with populations from Central and West Asia, as well as several Chinese groups. However, the AISNP analyses demonstrated that the Northwest Hui group shared more intimate relationships with current East Asian populations apart from reference Hui group, harboring the large proportion of ancestral component contributed by East Asia.

Genetic analysis of 32 InDels in four ethnic minorities from Chinese Xinjiang

The present study used the previously constructed 32-plex InDels panel to investigated the genetic diversity of four ethnic minorities (Hui, Mongol, Uygur and Kazakh) from Xinjiang, and analyzed the genetic relationships between the four populations and 27 reference populations. No significant deviations were observed from the Hardy-Weinberg equilibrium (HWE) at the 32 InDels for each population. The average observed heterozygosity (H_exp), average polymorphic information content (PIC), combined power of discrimination (CPD) and cumulative probability of exclusion (CPE) for the 32 InDels were all higher than the Qiagen Investigator DIPplex kit in the four populations from Xinjiang. The CPD ranged from 0.999999999999903 (Kazakh) to 0.999999999999952 (Hui) and CPE ranged from 0.9971 (Uygur) to 0.9985 (Hui), which indicated that the 32 InDels were capable for individual identification and could be a supplementary tool in paternity test for these populations. Population genetic analysis by the method of analysis of molecular variance (AMOVA), F_ST, phylogenetic tree, TreeMix-based topology, multi-dimensional scale analysis (MDS), principal components analysis (PCA) and STRUCTURE analysis showed that Xinjiang Hui population has a close relationship with East Asians (EAS), especially Chinese Han, and the populations of Xinjiang Mongol, Uygur and Kazakh showed mixed ancestral components related to EAS and Europeans (EUR).

A Novel Panel of 43 Insertion/Deletion Loci for Human Identifications of Forensic Degraded DNA Samples: Development and Validation

Insertion/deletion polymorphism is a promising genetic marker in the forensic genetic fields, especially in the forensic application of degraded sample at crime scene. In this research, a novel five-dye multiplex amplification panel containing 43 highly polymorphic Insertion/deletion (InDel) loci and one Amelogenin gene locus is designed and constructed in-house for the individual identification in East Asian populations. The amplicon sizes of 43 InDel loci are less than 200 bp, which help to ensure that full allele profiles can be obtained from degraded DNA sample. A series of optimizations and developmental validations including optimization of PCR conditions, detection efficiency of the degraded and casework samples, sensitivity, reproducibility, precision, tolerance for inhibitors, species specificity and DNA mixtures are performed according to the Scientific Working Group on DNA Analysis Methods (SWGDAM) guideline. The results of the internal validation demonstrated that this novel InDel panel was a reliable, sensitive and accurate system with good tolerances to different inhibitors, and performed the considerable detection efficiency for the degraded or mixed samples, which could be used in the forensic applications.

The Polymorphism Analyses of Short Tandem Repeats as a Basis for Understanding the Genetic Characteristics of the Guanzhong Han Population

The short tandem repeat (STR) loci are polymorphic markers in the combined DNA index system (CODIS) and non-CODIS STR loci. Due to the highly polymorphic characteristic of STR loci, they are popular and widely used in forensic DNA typing laboratories. In this study, 22 STR loci (1 CODIS, 21 non-CODIS STR loci) and an Amelogenin locus were genotyped and analyzed in 590 unrelated individuals of the Guanzhong Han population. None of the 22 STR loci deviated from the Hardy-Weinberg equilibrium, and all the loci were in the linkage equilibrium state. We observed 247 alleles, and the corresponding allelic frequencies ranged from 0.0008 to 0.3695 in the Guanzhong Han population. The combined power of discrimination and the cumulative exclusion probability was 0.999 999 999 999 999 999 999 999 999 346 36 and 0.999 999 999 709 74, respectively. The results including Nei's D _A genetic distance, multidimensional scaling analysis, and principal component analysis showed that the Guanzhong Han population has closer genetic affinities with Northern Han, Chengdu Han, and Xinjiang Hui groups from China based on allelic frequencies of 15 overlapped STR loci from Guanzhong Han and 13 reference groups. The present results indicated that Microreader™ 23sp ID kit included highly polymorphic loci, and it could be well used for individual identification, paternity testing, and population genetics in the Guanzhong Han population.

Analysis of Structural Variants Reveal Novel Selective Regions in the Genome of Meishan Pigs by Whole Genome Sequencing

Structural variants (SVs) represent essential forms of genetic variation, and they are associated with various phenotypic traits in a wide range of important livestock species. However, the distribution of SVs in the pig genome has not been fully characterized, and the function of SVs in the economic traits of pig has rarely been studied, especially for most domestic pig breeds. Meishan pig is one of the most famous Chinese domestic pig breeds, with excellent reproductive performance. Here, to explore the genome characters of Meishan pig, we construct an SV map of porcine using whole-genome sequencing data and report 33,698 SVs in 305 individuals of 55 globally distributed pig breeds. We perform selective signature analysis using these SVs, and a number of candidate variants are successfully identified. Especially for the Meishan pig, 64 novel significant selection regions are detected in its genome. A 140-bp deletion in the Indoleamine 2,3-Dioxygenase 2 (IDO2) gene, is shown to be associated with reproduction traits in Meishan pig. In addition, we detect two duplications only existing in Meishan pig. Moreover, the two duplications are separately located in cytochrome P450 family 2 subfamily J member 2 (CYP2J2) gene and phospholipase A2 group IVA (PLA2G4A) gene, which are related to the reproduction trait. Our study provides new insights into the role of selection in SVs' evolution and how SVs contribute to phenotypic variation in pigs.

The Genetic Structure of Chinese Hui Ethnic Group Revealed by Complete Mitochondrial Genome Analyses Using Massively Parallel Sequencing

Mitochondrial DNA (mtDNA), coupled with maternal inheritance and relatively high mutation rates, provides a pivotal way for us to investigate the formation histories of populations. The Hui minority with Islamic faith is one of the most widely distributed ethnic groups in China. However, the exploration of Hui's genetic architecture from the complete mitochondrial genome perspective has not been detected yet. Therefore, in this study, we employed the complete mitochondrial genomes of 98 healthy and unrelated individuals from Northwest China, as well as 99 previously published populations containing 7274 individuals from all over the world as reference data, to comprehensively dissect the matrilineal landscape of Hui group. Our results demonstrated that Hui group exhibited closer genetic relationships with Chinese Han populations from different regions, which was largely attributable to the widespread of haplogroups D4, D5, M7, B4, and F1 in these populations. The demographic expansion of Hui group might occur during the Late Pleistocene. Finally, we also found that Hui group might have gene exchanges with Uygur, Tibetan, and Tajik groups in different degrees and retained minor genetic imprint of European-specific lineages, therefore, hinting the existence of multi-ethnic integration events in shaping the genetic landscape of Chinese Hui group.

Forensic parameters and genetic structure analysis of 30 autosomal InDels of the population in Freetown, Sierra Leone

As the origin of modern humanity, African populations show high genetic diversity and are attracting increasing academic attention. However, populations living in West Africa have so far received less study and exploration. In this study, we analyze 30 insertion/deletion (InDel) loci of 516 samples from Freetown, Sierra Leone, to evaluate the forensic properties and reveal the genetic structure in Freetown, Sierra Leone, West Africa. No significant linkage disequilibrium (LD) between 30 InDels was observed after the Bonferroni correction. The random match probability (RMP), the combined power of exclusion for duos (CPE duos), and the combined power of exclusion for trios (CPE trios) were 6.823 × 10^-11, 0.9168, and 0.9731, respectively. Null alleles and off-ladder alleles were observed, suggesting that we should be cautious when using this kit for forensic caseworks in African populations. In the population comparison study, we found that the Freetown population is genetically closer to geographically distinct West Africans and has a closer genetic relationship with the Bantu-speaking populations than other African populations.

Forensic applicability of autosomal insertion/deletion loci in Chinese Daur ethnic group and genetic affinity evaluations between Daur group and reference populations

In present study, we evaluated the genetic diversities of 30 insertion/deletion (InDel) loci and analyzed the genetic relationships between Daur and other comparison populations. In the studied Daur group, any two InDel loci showed no linkage disequilibrium, and all loci showed no deviations from exact tests of Hardy-Weinberg equilibrium. Insertion allele frequencies at 30 InDel loci ranged from 0.1459 (HLD39) to 0.8774 (HLD118). The observed heterozygosity and expected heterozygosity values were ranged from 0.1984 (HLD118) to 0.5564 (HLD6) and 0.2155 (HLD118) to 0.5000 (HLD92 and HLD6), respectively. The combined power of discrimination and power of exclusion values were 0.999999999993428 and 0.9878, respectively, which indicated that this panel of 30 InDels could be used for individual identifications in Daur group. Population genetic analyses including pairwise fixation index, STRUCTURE analysis, principal component analysis, genetic distance, multidimensional scaling analysis and phylogenetic analysis demonstrated that the Daur group had the closer genetic relationships with the groups from western China in comparison with other continental populations.

Forensic characteristic and population structure dissection of Shaanxi Han population in the light of diallelic deletion/insertion polymorphism data

The genetic polymorphisms of diallelic deletion/insertion polymorphic (DIP) loci in the Shaanxi Han population are still not clearly characterized. Herein, allele frequencies and forensic application efficiencies for 30 diallelic DIP loci were investigated in 506 unrelated healthy Han individuals from Chinese Shaanxi province. Based on population data of the same 30 diallelic DIP loci, the genetic differentiations, hierarchical clustering relationships and population architectures among Shaanxi Han and other 50 populations were further dissected through genetic and bioinformatics analyses. Results indicated that most of the 30 diallelic DIP loci were relatively high polymorphisms in the Shaanxi Han population; and there were the genetically intimate relationships between Shaanxi Han and the East Asian populations. In summary, this study provided significant insights into genetic background of Shaanxi Han population, and the multiplex amplification of these 30 diallelic DIP loci was appropriate for forensic individual identification and population genetic research in Shaanxi Han population.

Ancestry Prediction Comparisons of Different AISNPs for Five Continental Populations and Population Structure Dissection of the Xinjiang Hui Group via a Self-Developed Panel

Ancestry informative markers are genetic markers that show distinct genetic divergences among different populations. These markers can be utilized to discern population substructures and estimate the ancestral origins of unknown individuals. Previously, we developed a multiplex system of 30 ancestry informative single nucleotide polymorphism (AISNP) loci to facilitate ancestral inferences in different continental populations. In the current study, we first compared the ancestry resolutions of the 30 AISNPs and the other previously reported AISNP panels for African, European, East Asian, South Asian and American populations. Next, the genetic components of the Xinjiang Hui group were further explored in comparison to these continental populations based on the 30 AISNPs. Genetic divergence analyses of the 30 AISNPs in these five continental populations revealed that most of the AISNPs showed high genetic differentiations between these populations. Ancestry analysis comparisons of the 30 AISNPs and other published AISNPs revealed that these 30 AISNPs had comparable efficiency to other AISNP panels. Genetic relationship analyses among the studied Hui group and other continental populations demonstrated that the Hui group had close genetic affinities with East Asian populations and might share the genetic ancestries with East Asian populations. Overall, the 30 AISNPs can be used to predict the bio-geographical origins of different continental populations. Moreover, the obtained genetic data of 30 AISNPs in the Hui group can further enrich the extant reference data, which can be used as reference data for ancestry analyses of the Hui group.

Haplotype diversity and phylogenetic characteristics for Guanzhong Han population from Northwest China via 38 Y-STRs using Yfiler™ Platinum Amplification System

BACKGROUND

For better application in human forensic cases and population genetics research, it is imperative to investigate the genetic characteristics of Guanzhong Han population using enhanced Y-chromosomal short tandem repeats (Y-STR) detecting system with higher discriminating power than previous ones.

METHODS

In this study, 38 Y-STRs were profiled in 430 unrelated Chinese Han male individuals from Guanzhong region of Shaanxi Province, Northwest China, using the Yfiler™ Platinum PCR Amplification Kit. Haplotype frequencies and forensic parameters were calculated. Comprehensive population comparisons with geographically/ethnically different populations in China and other worldwide countries were performed.

RESULTS

A total of 422 different haplotypes were observed with the overall haplotype diversity (HD), discriminatory power (DC) and haplotype match probability (HMP) were 0.9999, 0.9814, and 0.0024, respectively. Guanzhong Han showed genetically affinity with Han ethnicity from Shanxi and Henan provinces, while far distant from Tibetan populations.

CONCLUSION

This study offered a unique insight into Guanzhong Han population, the 38 Y-STRs included in the the Yfiler™ Platinum system are highly polymorphic and informative and can be used for forensic practice and human genetic research.

Genetic diversity and phylogenetic structure of four Tibeto-Burman-speaking populations in Tibetan-Yi corridor revealed by insertion/deletion polymorphisms

BACKGROUND

Insertion/deletion polymorphisms (InDels), combined with all the desirable features of both short tandem repeat and single nucleotide polymorphism, have been used in archaeological and anthropological research, population genetics and forensic application.

METHODS

Thirty InDels in 530 individuals residing in the Tibetan-Yi corridor (142 Dujiangyan Tibetans, 164 Muli Tibetans, 187 Xichang Yis, and 37 Yanyuan Mosuos) were genotyped using the Investigator DIPplex. Forensic parameters and allele frequency spectrum were calculated. Genetic relationships between the investigated populations and worldwide and nationwide populations were assessed based on both the allele frequency distribution and genotype data.

RESULTS

The combined powers of exclusion were 0.9807 (Dujiangyan Tibetan), 0.9880 (Muli Tibetan), 0.9852 (Xichang Yi) and 0.9892 (Yanyuan Mosuo). The combined powers of discrimination were 0.999999999983 (Dujiangyan Tibetan), 0.999999999942 (Muli Tibetan), 0.999999999982 (Xichang Yi) and 0.999999999962 (Yanyuan Mosuo), respectively. The comprehensive population comparisons among worldwide and nationwide populations uniformly illustrated that the investigated populations have a genetically closer relationship with Tibeto-Burman-speaking populations and geographically adjacent populations.

CONCLUSION

These 30 loci can be regarded as an efficient genetic tool in forensic individual identification and as a supplementary tool in paternity testing in Dujiangyan Tibetan, Muli Tibetan, Xichang Yi, and Yanyuan Mosuo. The genetic proximity between the four populations in the Tibetan-Yi corridor and other populations is strongly correlated with the linguistic origin and geographical distance.

Genetic variation and population structure analysis of Chinese Wuzhong Hui population using 30 Indels

Background: Insertions and deletions (Indels) have been used in routine forensic studies, archaeology, and population genetics. They have certain advantages, such as absence of stutter, small amplicon lengths, and low mutation rates. The genetic variations and forensic features of Indels in the Wuzhong Hui population are, as yet, unclear.Aim: To investigate the genetic polymorphisms of 30 Indels in Wuzhong Hui people and explore their genetic relationship with 48 reference populations from all over the world.Subjects and methods: We genotyped 30 Indels included in the Investigator DIPplex Kit in 156 Wuzhong Hui individuals. The genetic polymorphisms and population genetic relationships were analysed and explored via pairwise Fst, principal component analysis, multidimensional scaling plots, phylogenetic tree, and structure.Results: The combined power of discrimination (CPD) and the combined probability of exclusion (CPE) were 0.9999999999899 and 0.9880, respectively. Population genetic diversity and affinity were associated with geographic origin and linguistic affiliation.Conclusions: The 30 Indels can be utilised as an important tool in forensic personal identification and as a supplementary method in paternity testing in Wuzhong Hui. The Wuzhong Hui people have a close genetic relationship with populations of geographical proximity and Sinitic-speaking populations, while they are different from other continental populations and Turkic-speaking populations.

An innovative panel containing a set of insertion/deletion loci for individual identification and its forensic efficiency evaluations in Chinese Hui ethnic minority

BACKGROUND

Individual identification is one of the most important tasks in the field of forensic genetics. Insertion/Deletion (InDel) polymorphism marker has been a promising marker for individual identification. However, a part of InDel loci in commonly used commercial kit show low polymorphisms in Chinese populations.

METHODS

We evaluated a panel of 35 InDel loci constructed previously for individual identifications in Hui group. Subsequently, population data of three Chinese populations from 1,000 Genomes Project database were used to evaluate individual identification performance of these 35 InDels. Forensic parameters, such as heterozygosity, power of exclusion, match probability and power of discrimination, were calculated to evaluate the forensic efficiency of these loci in Hui group. The heatmap of insertion allelic frequencies, Nei's genetic distances, pairwise fixation index values, principal component analyses and admixture analyses were used to analyze the genetic differentiations and structure between Hui group and other populations.

RESULTS

In studied Hui group, besides rs3054057, polymorphism information content values of the remaining loci were greater than 0.3. Values of expected heterozygosity of these loci were close to 0.5. The combined power of discrimination and power of exclusion values were 0.99999999999999659609 and 0.998682, respectively. Analyses of population genetics revealed that Chinese Hui group had closer genetic relationships with East Asian populations than other intercontinental populations.

CONCLUSION

The forensic statistical analyses revealed these loci showed relatively high genetic polymorphisms in Chinese Hui group, and could be served as a useful tool for individual identifications in Hui group. Population genetic evaluations indicated that Chinese Hui group had close genetic relationships with East Asian populations.

Genetic affinity between Ningxia Hui and eastern Asian populations revealed by a set of InDel loci

According to historical records, ethnic Hui in China obtained substantial genetic components from western Eurasian populations during their Islamization. However, some scholars believed that the ancestry of Hui people were native Chinese populations. In this context, the formation of Hui is due to simple cultural diffusion rather than demic diffusion. In this study, we examined the forensic and population genetic application of the 30 InDel loci in Hui population from Ningxia Hui Autonomous Region, Northwest China. Genotype analysis of 129 unrelated individuals revealed that all loci were in the Hardy-Weinberg equilibrium in Ningxia Hui. Forensic indices calculated from genotypes demonstrated that this panel, Qiagen DIPplex® Investigator kit, was powerful enough to be used in individual identification but not in paternity cases. Through population genetic analysis, we found that Ningxia Hui received much more genetic contributions from East Asian populations than those from western Eurasian populations. Finally, we statistically identified the admixture signal of eastern and western Eurasians, although the latter is weak, in Ningxia Hui via the three-population test. All this evidence suggested that the formation of Ningxia Hui was mainly attributed to the cultural transformation of local Chinese residents with minor gene flow from western Eurasian populations.

Genetic diversity and phylogenetic analysis of Chinese Han and Li ethnic populations from Hainan Island by 30 autosomal insertion/deletion polymorphisms

With the characteristics of low mutation rate, length variation and short amplicon size, insertion/deletion polymorphisms (InDels) have the advantages of both short tandem repeats (STRs) and single nucleotide polymorphisms (SNPs). Herein, people of two ethnicities from Hainan Island were genotyped for the first time using the Investigator DIPplex kit. We investigated the forensic parameters of the 30 InDels and the phylogenetic relationships among different populations. The accumulated powers of discrimination and powers of exclusion were 0.999 999 999 9646 and 0.9897 in the Hainan Han population and 0.999 999 999 9292 and 0.9861 in the Hainan Li population, respectively. Additionally, population comparisons among geographically, ethnically and linguistically diverse populations via cluster heatmap, multidimensional scaling, principal component analysis, phylogenetic tree and STRUCTURE analyses demonstrated that the Hainan Han population had genetic similarities to the other Han, She and Tujia populations, while the Hainan Li population had close genetic relationships to the Zhuang and Miao groups; both populations had a high degree of genetic differentiation from most Turkic-speaking populations. Aforementioned results suggested that the 30 autosomal InDels are highly polymorphic and informative, which are suitable for human identification and population genetics.

Four hundred and forty-five Chinese individuals from two ethnicities (Hainan Han and Hainan Li) were firstly analyzed by 30 autosomal InDels included in the Investigator DIPplex panel.

Forensic parameters of the 30 InDels in the two populations showed high polymorphism and universality for human identification purposes.

The Investigator DIPplex panel had a certain capacity of differentiating intercontinental populations and different language populations.

Genetic diversity, structure and forensic characteristics of Hmong-Mien-speaking Miao revealed by autosomal insertion/deletion markers

Insertion/deletion (Indel) genetic markers have special features compared to other forensic-related markers, such as the low mutation rate and di-allelic markers with length polymorphism, playing an indispensable role in the forensic and population genetics, molecular anthropology and evolutionary biology. However, the genetic diversity, allelic frequency, forensic parameters and population genetic characteristics of the Indel markers in Hmong-Mien-speaking Guizhou Miao people are unclear due to the sparse sampling. Thus, we genotyped 30 forensic-related Indel markers in 311 unrelated healthy Miao individuals (149 females and 161 males) residing in the Guizhou Province in Southwest China using the Investigator DIPplex amplification system. All 30 Indels are in accordance with the no departures of Hardy-Weinberg equilibrium and linkage disequilibrium. The combined probability of discrimination and the probability of exclusion in Guizhou Miao population are 0.999999999948 and 0.9843, respectively. This observed ideal forensic parameter estimates indicate that this di-allelic Indel panel can be used as a supplementary tool in forensic retinue personal identification and complemented for autosomal STRs in the parentage testing in Miao population, especially used as the main tool in old or highly degraded samples in disaster victim identification. Eleven Indels show a high allele frequency difference between different continental populations and could be used as ancestry-informative markers in forensic ancestry inference. Phylogenetic relationships between Guizhou Miao and 68 worldwide populations based on the genetic polymorphisms of Indels are investigated via three different pairwise genetic distances, principal component analysis, multidimensional scaling analysis and phylogenetic relationship reconstructions. Analyses of the comprehensive population genetic relationship comparison reveal significant genetic differentiation of Chinese groups. Our results demonstrate that Guizhou Miao people are genetically closer related to the geographically adjacent populations, especially with Liangshan Yi, Guangxi Miao and Dong, but genetically distinct with Turkic-speaking populations. Comprehensive and precise genetic admixture and divergence history of Guizhou Miao and neighboring populations are needed to further investigate and reconstruct via high-density marker panel or whole-genome sequencing of modern or ancient Miao samples.

Forensic performance of 30 InDels included in the Investigator DIPplex system in Miao population and comprehensive genetic relationship in China

Binary markers of insertion and deletion (InDel) play an important role in forensic personal identification, parentage testing, and individual ancestry inference. We first genotyped 30 InDels included in the Investigator DIPplex in 403 unrelated healthy Zunyi Miao people and analyzed the genetic polymorphisms, as well as explored the genetic relationship between Miao and 32 Chinese reference populations. No departures from the HWE were observed. The combined power of discrimination and the combined probability of exclusion were 0.99999999998 and 0.9884, respectively. Forensic parameters demonstrated that 30 markers are polymorphic and informative in the Zunyi Miao population and can be used as a tool for forensic personal identification and parentage testing. Allele frequency divergence analysis found that 12 out of 30 displaying high allele frequency difference between Turkic-speaking populations and other Chinese populations can be used as candidates of ancestry informative markers for ancestry inference of sub-population in East Asia. Population genetic parameters in the comprehensive population comparison among 33 Chinese populations indicated that our studied Hmong-Mien-speaking Miao has a close genetic relationship with geographically adjacent Enshi Tujia and genetically differentiate from Turkic-speaking populations.

Genetic structure and forensic parameters of 30 InDels for human identification purposes in 10 Tibetan populations of China

Insertion/deletion analysis can serve as a promising and useful supporting tool in forensic research. The Qiagen Investigator® DIPplex Kit contained 30 well-chosen autosomal InDels was targeted to reveal the population genetic variation. In the present study, 10 Tibetan populations residing in different geographic areas of China were recruited and genotyped by Investigator® DIPplex Kit. Allele frequencies and forensic parameters were determined. No significant departures from Hard-Weinberg equilibrium (HWE) in all loci/populations after Bonferroni correction. The combined matching probability values range from 1.7148 × 10^-11 to 5.3516 × 10^-1° in 10 Tibetan populations. Our results revealed 10 Tibetan populations in China are genetically very similar. Intercontinental population differentiation analysis indicated Tibetan populations had a close genetic relationship with East Asian populations using Hierarchical clustering, multi-dimensional scaling (MDS), principal component analysis (PCA) and STRUCTURE. Comprehensive population genetic studies revealed that the 30-InDels assay was similarly efficient in forensic personal identification and could be regarded as an effective supplementary protocol for kinship testing.

Population Genetic Diversity and Clustering Analysis for Chinese Dongxiang Group With 30 Autosomal InDel Loci Simultaneously Analyzed

In comparison with the most preferred genetic marker utilized in forensic science (STR), insertion/deletion analysis possesses further benefits, like absence of stutter peak, low mutation rate, and enabling mixed stain analysis. At present, a total of 169 unrelated healthy Dongxiang individuals dwelling in Dongxiang Autonomous county of Gansu province were recruited in our study to appraise the forensic usefulness of the panel including 30 autosomal diallelic genetic markers. The insertion allele frequencies were in the range of 0.1598 at HLD 111 to 0.8550 at HLD 118. The cumulative match of probability and the combined probability of exclusion were estimated based on independence of pairwise loci, with the values of 3.96 × 10^-11 and 0.9886, respectively, which showed tremendous potential of this panel to be qualified for forensic personal identification in Chinese Dongxiang group. And it could also be used as a complementary tool for forensic parentage testing when combined with standard STR genetic markers. Furthermore, calculation of the D_A distance and F_st values of pairwise populations, phylogenetic reconstruction, multidimensional scaling analysis, structure clustering analysis were also conducted to probe the genetic relationships between Dongxiang group and the other 30 reference populations. Results demonstrated that Dongxiang ethnic group might be genetically closer related with most Chinese populations involved in our study, especially Tibet groups, Xibe group, and several Han populations.