Autosomal Markers Research Articles

SNP analysis of challenging bone DNA samples using the HID-Ion AmpliSeq™ Identity Panel: facts and artefacts

PCR-MPS is an emerging tool for the analysis of low-quality DNA samples. In this study, we used PCR-MPS to analyse 32 challenging bone DNA samples from three Second World War victims, which previously yielded no results in conventional STR PCR-CE typing. The Identity Panel was used with 27 cycles of PCR. Despite that we only had an average of 6.8 pg of degraded DNA as template, 30 out of 32 libraries (93.8%) produced sequencing data for about 63/90 autosomal markers per sample. Out of the 30 libraries, 14 (46.7%) yielded single source genetic profiles in agreement with the biological identity of the donor, whereas 12 cases (40.0%) resulted in SNP profiles that did not match or were mixed. The misleading outcomes for those 12 cases were likely due to hidden exogenous human contamination, as shown by the higher frequencies of allelic imbalance, unusual high frequencies of allelic drop-ins, high heterozygosity levels in the consensus profiles generated from challenging samples, and traces of amplified molecular products in four out of eight extraction negative controls. Even if the source and the time of the contamination were not identified, it is likely that it occurred along the multi-step bone processing workflow. Our results suggest that only positive identification by statistical tools (e.g. likelihood ratio) should be accepted as reliable; oppositely, the results leading to exclusion should be treated as inconclusive because of potential contamination issues. Finally, strategies are discussed for monitoring the workflow of extremely challenging bone samples in PCR-MPS experiments with an increased number of PCR cycles.

Internal validation study to assess the SeqStudio™ for human identification’s performance

The SeqStudio™ for human identification (HID) is a new benchtop capillary electrophoresis (CE) platform recently developed by Applied Biosystems for genotyping and sequencing short tandem repeat (STR) fragments. Compared to the previous series of CE systems developed by this maker, it is more compact and easier to use. Moreover, by allowing the detection of 4 to 8 fluorescent dyes, it seems to be fully compatible with the different kits of autosomal and gonosomal STR markers usually used in forensic genetics, which are available in trade and supplied by various manufacturers. However, being a new CE model, before its routine use in forensic genetics applications, it should undergo appropriate analytical validation studies in its own laboratories to understand its potential and limitations. A series of experiments on DNA samples coming from cell line controls, using the GlobalFiler™ IQC Amplification Kit, were carried out to meet this purpose. The SeqStudio™ Genetic Analyzer for HID’s findings on genotyping reproducibility (precision and accuracy of sizing), sensitivity, signal variability between dyes (intra- and inter-color channel balance), and stutter ratios are reported. These findings confirm the validity of this new CE system and its capability to generate reliable results.

Systematic revision of the ‘diminutive’ Kentish Plover (Charadriidae: Charadrius) with the resurrection of Charadrius seebohmi based on phenotypic and genetic analyses

The Kentish Plover Charadrius alexandrinus Linnaeus 1758 is a common shorebird in Eurasia and North Africa that breeds in a variety of habitats, exhibits different extents of migratory behaviour and is an emerging model species of breeding system evolution. Here we focus on the resident population found across the southern tip of India and Sri Lanka, and re‐evaluate its systematic status based on phenotypic and genetic distinctiveness from a sympatric migrant, Charadrius alexandrinus sensu stricto, and the recently elevated closely related Charadrius dealbatus in East Asia. We show that the Sri Lankan and South Indian (South Asian) population differs in body size, moulting pattern and plumage coloration from C. alexandrinus and C. dealbatus. Furthermore, based on two mitochondrial, two sex‐linked and 11 autosomal microsatellite markers from 378 individuals, we show that these three taxa have moderate genetic differentiation (Fst 0.078–0.096). The South Asian taxon is sister to the clade of C. alexandrinus sensu stricto and C. dealbatus with an estimated divergence time of 1.19 million years ago. We also examined ornithological records of major museum collections in Asia, Europe and North America for the south Asian taxon to evaluate its biogeographical and taxonomic status. Based on differences in genotype, phenotype, allochronic migratory pattern and breeding range, we resurrect the most suitable synonym, Charadrius alexandrinus seebohmi Hartert and Jackson, 1915, and elevate the nomen to the species level with the proposed English name ‘Hanuman Plover’.

Древняя ДНК носителей фатьяновской и абашевской культур (к вопросу о миграциях населения эпохи бронзы в лесной полосе на Русской равнине)

This study addresses a fundamental question of the origins and migration patterns of paleopopulations of the Fatyanovo and the Middle Volga Abashevo archaeological cultures. It is for the first time that we report a paleogenetic analysis of 14 Abashevo individuals (Pepkino and Starshy Nikitinsky sites). Besides, we analysed ancient DNA samples of 25 Fatyanovo individuals. Specifically, we performed analyses of STR marker and haplogroups of the Y chromosome, which revealed the distinct R1a (Z93) haplogroup in Fatyanovo samples. It indicates the influence of the founder effect and gene drift, confirming the hypothesis of their migrant origin. In contrast, the Abashevo culture samples are heterogenous, as we discovered 2 groups with different origins on the paternal line. To be more specific, three men from Pepkino mound are haplogroup R1b (Z2103) carriers, while seven other individuals have haplogroup R1a (Z93>Z94). In addition, close relatives with identical STR haplotypes of the Y-chromosome were identified in both Fatyanovo and Abashevo groups. The comparative analyses of autosomal markers from 19 samples and previously published data uncovered similarities between Abashevo men from Pepkino mound (the haplogroup R1a (Z93>Z94)) with the Fatyanovo people, as well as with some representatives of the Unetice culture. These results are suggestive of the genetic continuity in the Russian Plain. Yet, less recent ancestors of Abashevo group interred in Pepkino mound could have migrated from the same region as the Fatyanovo predesessors.

The Baron Pasquale Revoltella's Will in the Forensic Genetics Era.

In this article, we describe multiple analytical strategies that were first developed for forensic purposes, on a set of three bone samples collected in 2011. We analyzed a single bone sample (patella) collected from the artificially mummified body of the Baron Pasquale Revoltella (1795-1869), as well two femurs which allegedly belonged to the Baron's mother (Domenica Privato Revoltella, 1775-1830). Likely due to the artificial mummification procedures, the inner part of the Baron's patella allowed the extraction of high-quality DNA yields, which were successfully used for PCR-CE and PCR-MPS typing of autosomal, Y-specific, and mitochondrial markers. The samples extracted from the trabecular inner part of the two femurs yielded no typing results by using the SNP identity panel, whereas the samples extracted from the compact cortical part of the same bone samples allowed genetic typing, even by the employment of PCR-CE technology. Altogether, 10/15 STR markers, 80/90 identity SNP markers, and HVR1, HVR2, and HVR3 regions of the mtDNA were successfully typed from the Baron's mother's remains by the combined use of PCR-CE and PCR-MPS technologies. The kinship analysis showed a likelihood ratio of at least 9.1 × 106 (corresponding to a probability of maternity of 99.9999999%), and thus confirmed the identity of the skeletal remains as those of the Baron's mother. This casework represented a challenging trial for testing forensic protocols on aged bones samples. It highlighted the importance of accurately sampling from the long bones, and that DNA degradation is not blocked by freezing at -80 °C.

Relationship of the gene pool of the Khants with the peoples of Western Siberia, Cis-Urals and the Altai-Sayan Region according to the data on the polymorphism of autosomic locus and the Y-chromosome.

Khanty are indigenous Siberian people living on the territory of Western Siberia, mainly on the territory of the Khanty-Mansiysk and Yamalo-Nenets Autonomous Okrugs. The present study is aimed at a comprehensive analysis of the structure of the Khanty gene pool and their comparison with other populations of the indigenous population of Southern and Western Siberia. To address the issues of genetic proximity of the Khanty with other indigenous peoples, we performed genotyping of a wide genomic set of autosomal markers using high-density biochips, as well as an expanded set of SNP and STR markers of the Y-chromosome in various ethnic groups: Khakas, Tuvans, Southern Altaians, Siberian Tatars, Chulyms (Turkic language family) and Kets (Yeniseian language family). The structure of the gene pool of the Khanty and other West Siberian and South Siberian populations was studied using a genome-wide panel of autosomal single nucleotide polymorphic markers and Y-chromosome markers. The results of the analysis of autosomal SNPs frequencies by various methods, the similarities in the composition of the Y-chromosome haplogroups and YSTR haplotypes indicate that the Khanty gene pool is quite specific. When analyzing autosomal SNPs, the Ugrian genetic component completely dominates in both samples (up to 99-100 %). The samples of the Khanty showed the maximum match in IBD blocks with each other, with a sample of the Kets, Chulyms, Tuvans, Tomsk Tatars, Khakas, Kachins, and Southern Altaians. The degree of coincidence of IBD blocks between the Khanty, Kets, and Tomsk Tatars is consistent with the results of the distribution of allele frequencies and common genetic components in these populations. According to the composition of the Y-chromosome haplogroups, the two samples of the Khanty differ significantly from each other. A detailed phylogenetic analysis of various Y-chromosome haplogroups made it possible to describe and clarify the differences in the phylogeny and structure of individual ethnospecific sublines, to determine their relationship, traces of population expansion in the Khanty gene pool. Variants of different haplogroups of the Y-chromosome in the Khanty, Khakas and Tuvans go back to their common ancestral lines. The results of a comparative analysis of male samples indicate a close genetic relationship between the Khanty and Nenets, Komi, Udmurts and Kets. The specificity of haplotypes, the discovery of various terminal SNPs confirms that the Khanty did not come into contact with other ethnic groups for a long time, except for the Nenets, which included many Khanty clans.

Structure and origin of Tuvan gene pool according to autosome SNP and Y-chromosome haplogroups.

Tuvans are one of the most compactly living peoples of Southern Siberia, settled mainly in the territory of Tuva. The gene pool of the Tuvans is quite isolated, due to endogamy and a very low frequency of interethnic marriages. The structure of the gene pool of the Tuvans and other Siberian populations was studied using a genome-wide panel of autosomal single nucleotide polymorphic markers and Y-chromosome markers. The results of the analysis of the frequencies of autosomal SNPs by various methods, the similarities in the composition of the Y-chromosome haplogroups and YSTR haplotypes show that the gene pool of the Tuvans is very heterogeneous in terms of the composition of genetic components. It includes the ancient autochthonous Yeniseian component, which dominates among the Chulym Turks and Kets, the East Siberian component, which prevails among the Yakuts and Evenks, and the Far Eastern component, the frequency of which is maximum among the Nivkhs and Udeges. Analysis of the composition of IBD-blocks on autosomes shows the maximum genetic relationship of the Tuvans with the Southern Altaians, Khakas and Shors, who were formed during the settlement of the Turkic groups of populations on the territory of the Altai-Sayan region. A very diverse composition of the Tuvan gene pool is shown for various sublines of Y-chromosomal haplogroups, most of which show strong ethnic specificity. Phylogenetic analysis of individual Y-chromosome haplogroups demonstrates the maximum proximity of the gene pool of the Tuvans with the Altaians, Khakas and Shors. Differences in frequencies of Y-chromosome haplogroups between the Todzhans and Tuvans and a change in the frequencies of haplogroups from south to north associated with the East Asian component were found. The majority of the most frequent Y-chromosome haplogroups in the Tuvans demonstrate the founder effect, the formation age of which is fully consistent with the data on their ethnogenesis.

Genetic Variability of Small Horse Populations from Greek Islands

In this study, we analyzed microsatellite variation in DNA obtained from hair samples collected from 46 local Greek horse populations originating from the islands of Skyros (Skyros Small Horse; n=9), Rhodes (Rodos Small Horse; n=6), Lesvos (with the traditional miniature Midili Small Horse (n=2) and the larger Lesvos Gaiter (n=22)) and Crete (Messara) (n=7). We used 15 autosomal microsatellite markers (VHL20, HTG4, AHT4, HMS7, HTG6, AHT5, HMS6, ASB2, HTG10, HTG7, HMS3, HMS2, ASB17, ASB23 and LEX33) for the genetic characterization of the above populations and exploration of their genetic structure and diversity levels. A total of 120 alleles were detected across the 15 loci with a minimum of 4 alleles in HTG7 locus and a maximum of 13 alleles in ASB17 locus. Τhe total per population number of alleles was 42 (Skyros Small Horse), 20 (Rodos Small Horse), 71 (Lesvos Gaiter), 52 (Messara breed) and 21 (Midili Small Horse). The effective number of alleles (Ne) per locus ranged from 1.47±0.13 (Rodos Small Horse) to 4.67±0.31 (Lesvos Gaiter). The allelic richness (Ar) was between 1.50±0.12 (Rodos Small Horse) and 2.93±0.08 (Lesvos Gaiter) and the average Polymorphism Information Content (PIC) values varied from 0.200±0.035 (Rodos Small Horse) to 0.733±0.026 (Lesvos Gaiter). No significant deviations from H-W equilibrium were found except for three loci (ASB2, HTG10 and LEX33) in Messara and one locus (ASB23) in Lesvos Gaiter. Τhe inbreeding coefficient (Fis) ranged from -0.130 (Rodos Small Horse) to 0.042 (Lesvos Gaiter). The observed (Ho) and expected (He) multilocus heterozygosity mean estimations were highest in Lesvos Gaiter (0.764±0.027 and 0.783±0.024, respectively) and smallest in Rodos Small Horse (0.300±0.075 and 0.269±0.064, respectively). Across loci, the total genetic diversity HT was 0.741, the diversity among subpopulations HS was 0.621 and the multilocus genetic differentiation GST was 0.161, which was rather high. The population of Rodos Small Horse separated from the remaining horses as shown by factorial correspondence analysis, population assignment and metric multidimensional scaling diagrams. This study highlights the loss of genetic diversity in small isolated horse populations and the urgent need to take protective measures to preserve them.

Genetic Diversity of Autosomal STR Markers in the Brahmin Population of Rajasthan and Haryana: Significance in Population and Forensic Genetics.

A total of 203 male DNA samples from various districts of Haryana (n=104) and Rajasthan (n=99) were genotyped using the GlobalFiler® PCR Amplification Kit. Allelic frequencies and different forensic parameters like PD, PE, PIC, PM, Ho, He, UHe, and TPI were calculated with different software. More than 200 alleles were present in both populations, ranging from 6.0 to 35.2 and SE33 was the most polymorphic marker. The combined power of discrimination was 1. To know the relatedness with other Indian Brahmin populations, the UPGMA dendrogram and principal component analysis plot were visualized to show that both populations are close to each other and in nearby Saraswat Brahmins of Himachal Pradesh. This study showed a genetic relationship and forensic examination in the Haryana and Rajasthan Brahmin populations and various ethno-linguistically diverse populations of India. The results imply that the highly polymorphic 21 autosomal STR loci might be applied for individuals' forensic identification and parentage testing. This study also suggests that the kit having both autosomal and Y-STR markers is appropriate for a better understanding of the genetic and forensic examination in the Brahmin population of Haryana and Rajasthan.

DNA Phenotyping of Remains from Elite Burials of the Khazar Period of Southern Russia

Ancient DNA analyses help to solve the problems related to the genogeographic origin and migration patterns of populations. The Khazar Khaganate is a subject of controversy among researchers. Its complex historical development, lack of a sufficient number of artistic and written sources, the disappearance of representatives of Khazar culture leaves open the question of the appearance of the Khazars. DNA phenotyping of bone remains from elite burials of the Khazar period of Southern Russia was carried out with respect to eye color, hair color, skin color, and AB0 blood groups. Eight out of 10 individuals had brown eyes, dark hair (to varying degrees), and a predominantly dark skin during their lifetime. Individuals from two burials had gray-blue eyes, and one individual had blond hair. The most probable AB0 blood group was identified in eight people, of which five blood group 0 (I) group, four had blood group A (II), and one had blood group B (III). The allele frequency distribution was assessed for ten population-specific autosomal markers and suggested high heterogeneity for the ethnogeographic origin of the Khazars examined. The results are evidence for ethnocultural, genetic, and phenotypic diversity of the Khazar Khaganate.

Genetic differentiation of Andaman Islanders and their relatedness to Nicobar Islanders

The Andaman Islanders, living in isolation for centuries, have been subject to recent molecular scrutiny with their Asian origins being established. Although marked linguistic and physical variations are known to exist among the different extant population groups, the underlying genetic structure with reference to indigenous populations of adjacent Nicobar Islands has been poorly understood. To decipher the genetic structure of three indigenous Andaman Islanders; the Great Andamanese, Jarawa and the Onge, molecular analyses with autosomal, mitochondrial and Y-chromosomal markers were carried out and compared with indigenous Nicobar Islanders; the Nicobarese and Shompen.Biparental analyses revealed the Great Andamanese exhibiting considerable population substructuring owing to their present-day conglomeration of several erstwhile segregate tribes, in addition to discernable admixture from mainland Indian populations and other Andaman and Nicobar Islanders especially the Nicobarese. Distant separation between the Great Andamanese and Nicobarese was also discerned by the shared R22 mitochondrial lineage. The R22 lineage was previously reported in the Shompen of Nicobar Islands and Southeast Asian populations. The Nicobarese also exhibited mitochondrial haplogroup M74b, which has a Southeast Asian and East Asian distribution.The Onge-Jarawa group demonstrated a close genetic relatedness, consistent with their linguistic proximity. However, recent differentiation of the Jarawa from the Onge was also inferred from their separation on both mitochondrial M31 and M32 lineages as well as from autosomal and Y-chromosomal divergences. Our analyses indicate considerable genetic drift among the Andaman Islanders, a result of long-term isolation and inbreeding.Autosomal and mitochondrial data suggest considerable admixture between the ‘Negrito’ Great Andamanese and ‘non-Negrito’ Nicobarese.

Kinship analysis of skeletal remains from the Middle Ages

Medieval cemeteries Klisa-Guca Gora, Alihodze and Glavica-Han Bila located in the Travnik area (Travnik, Bosnia and Herzegovina) were archaeologically examined in the period 2011–2014, revealing human skeletal remains of 11 individuals in total. Archaeological skeletal samples, previously deposited in Travnik Homeland Museum (Travnik, Bosnia and Herzegovina) were subjected to genetic analysis. The aim of this research was to test familiar relationship of 11 individuals excavated from three medieval cemeteries and to predict Y-haplogroup for male individuals. In order to perform molecular-genetic characterisation of collected human skeletal remains, two systems of genetic markers were analysed: autosomal and Y-STR loci. Complete or partial data obtained by autosomal STR typing of 11 individuals were subjected to kinship analysis. Male sex was determined in eight samples out of 11. Direct relatives of the "brother-brother" type were detected in one case with high kinship probability (KP) value of 99.99996 %. Complete or nearly complete and usable Y-STR profiles were obtained for six out of eight male individuals. The presence of identical haplotypes at Y-STR loci and results of Y-haplogroup prediction suggest that all male individuals share the same paternal lineage and belong to J2a haplogroup. Overall, this study emphasises the usefulness, efficiency and sensitivity of STR markers in the molecular-genetic characterisation of old skeletal remains as well as the importance of employing additional markers like Y-STRs in archaeogenetic studies, besides traditionally used autosomal STR markers, in order to get a comprehensive information about close and distant relatives, and ancestry.

Forensic characterisation and polymorphism analysis of 16 X-chromosomal STRs in the Jining Han population in Eastern China

Background X-chromosomal short tandem repeats (X-STRs) are a useful supplementary approach to analysing autosomal markers in forensics and kinship studies; such markers are not well-characterised in many populations. Aim To investigate population genetic polymorphism and forensic characterisation of 16 X-STRs in the Jining Han population, and analyse genetic relationships with other Chinese populations. Subjects and methods Allele frequencies for 16 X-STR loci were obtained from a sample set of 527 unrelated individuals from the Jining Han population. Population genetic analyses of Jining Han and another 10 reference populations were conducted using phylogenetic tree, principal component analysis and multidimensional scaling. Results We detected 149 alleles, with frequencies ranging from 0.0013 to 0.8242. The combined powers of discrimination in males and females were 0.999999997194774 and 0.999999999999995, respectively. The combined mean exclusion change (MEC)Krüger, MECKishida, MECDesmarais, and MECDesmarais Duos values were 0.999974632649096, 0.999999976997582, 0.999999977013201, and 0.999993755768423, respectively. We detected relatively high genetic homogeneity in populations with similar ethnic or geographic origins, and a close relationship between the Jining Han and Beijing Han populations. Conclusions The present findings indicate that the 16 X-STR loci examined are highly polymorphic in the Han population of Jining, providing useful information for forensic science and population genetics studies.

Development and validation of a new multiplex for upgrading Y-STRs population databases from 12 to 23 markers and its forensic casework application

Y chromosomal short tandem repeats (Y-STRs) are used in forensic investigations as a useful complementary tool to autosomal markers. The ongoing development of new kits with an increasing number of markers makes it necessary to update populations typed in the Y-STR Haplotype Reference Database to reach at least 23 Y-STRs. A novel Y-STR multiplex panel was developed to offer a cost-efficient alternative to update Y-STR haplotypes from 12 to 23 loci. This panel includes the eleven markers, DYS448, DYS456, DYS458, DYS635, Y-GATA H4, DYS576, DYS481, DYS549, DYS533, DYS570 and DYS643, as well as DYS385a/b for traceability purpose. Developmental validation of this panel was conducted following the recommendations of the Scientific Working Group on DNA Analysis Methods (SWGDAM), showing high sensitivity, tolerance to common inhibitors as well as high species specificity. It was efficient for degraded DNA samples and for detection of male mixtures. When applying it for extending the current data of the Ibiza population, both the discrimination capacity and the haplotype diversity increased from 0.5952 to 0.9048 and from 0.9808 to 0.9977, respectively. Together, the study demonstrates the suitability of this panel in forensic casework.

Development of a new screening method for faster kinship analyses in mass disasters: a proof of concept study

Kinship analysis in forensics is based on the calculation of the respective kinship indices. However, this calculation is only possible when the subject under identification has been associated with a particular population, whose allele frequency data is available for the particular set of STR markers used in the forensic practices. In the case of mass disasters, where a large number of individuals are to be identified, gathering the population frequency data and calculating the kinship indices can be an intricate process which requires a lot of time and huge resources. The new method of allele matching cut off score (AMCOS) developed in this study is based on the allele sharing approach. This approach simply refers to the number of shared alleles (1 or 2) between the two individuals; also known as identical by state (IBS) alleles which might have been inherited from a recent common ancestor in which the alleles are identical by descendent (IBD). In case of mass disasters, this method can be used to narrow down the number of pairs (dead and alive) to be matched for kinship without using the allele frequency data. The results obtained from this method could further be confirmed by LR based method, which uses the allele frequency data of the respective population of the pairs being tested for kinship. AMCOS method has been tested for its sensitivity, specificity and various other statistical parameters and has shown promising values for the same in various types of kinship analyses. This ascertains the authenticity and potential use of this method in forensic practice but only after its validation in a larger sample size. AMCOS method has been tested on siblings and grandparent-grandchildren by using autosomal and X-STR markers both, as the reference samples from the parents cannot always be available for the identification. The present study also compared the results shown by the autosomal and X-STR markers in siblings and grandparent-grandchildren identification, thereby suggesting the use of better set of markers on the basis of obtained values of various statistical parameters.

Novel insights into the spatial genetic patterns of the finless porpoise from East to Southeast Asia

Several cetacean species are endemically distributed throughout the Indo-Pacific. Due to disproportionate sampling and research efforts across the Indo-Pacific region, the spatial genetic structure of these species remains poorly understood. This has led to poor phylogeographic knowledge and ambiguous taxonomic classification of many Indo-Pacific cetacean species. Of these, the finless porpoise (genus Neophocaena) is a small cetacean obligatory to the inshore waters from East Asia to the Persian Gulf of the Indian Ocean. To date, two species are generally recognized: the narrow-ridged finless porpoise inhabiting temperate and subtropical waters, and wide-ridged finless porpoises inhabiting subtropical and tropical waters. Early research efforts focused on the temperate waters off the northern China. However, recent studies have proposed that the primary divergence within the genus may lie between the Indian Ocean and Pacific region, which remains to be tested with more samples from tropical and subtropical regions. Here, we examined the genetic relationship among the finless porpoises from the Gulf of Thailand to the Taiwan Strait using both mitochondrial and autosomal markers. Bayesian assignment analysis suggested a minimum of four genetic populations within the study areas, corresponding to the narrow-ridged finless porpoise from the Taiwan Strait (TWSn), and the three wide-ridged finless porpoise populations from the Taiwan Strait (TWSw), Pearl River Delta region (PRDw), and the Gulf of Thailand (Thaiw), respectively. The minimum spanning network of the mtDNA control region found shared haplotypes among finless porpoises in Chinese waters, but those from the Gulf of Thailand formed a unique matriline lineage. Consistently, the genetic differentiation or divergence within the South China Sea (Thaiw vs. PRDw) appears to be higher than that of most finless porpoise populations examined to date, and meets the threshold values of species or sub-species level proposed for the cetacean species. The Mantel test detected a strong correlation between the geographic and genetic matrices within the South China Sea (r ​> ​0.99, p ​< ​0.001), indicating that the divergence associated with isolation-by-distance (IBD) has been accumulating in recent history. Our results imply that the formation and maintenance of the spatial genetic pattern of the finless porpoise is more complex than previously thought. However, this cannot be addressed by the current taxonomic classification of the genus.

Population Genetics of the European Roma-A Review.

The Roma are a group of populations with a common origin that share the Romani identity and cultural heritage. Their genetic history has been inferred through multiple studies based on uniparental and autosomal markers, and current genomic data have provided novel insights into their genetic background. This review was prompted by two factors: (i) new developments to estimate the genetic structure of the Roma at a fine-scale resolution have precisely identified the ancestral components and traced migrations that were previously documented only in historical sources, clarifying and solving debates on the origins and the diaspora of the Roma; (ii) while there has been an effort to review the health determinants of the Roma, the increasing literature on their population genetics has not been subjected to a dedicated review in the last two decades. We believe that a summary on the state of the art will benefit both the public and scholars that are approaching the subject.

Genetic variation of different Peruvian populations using 23 autosomal STR markers

In the present study the genetic variation of different Peruvian populations was investigated. The samples for this study were obtained from 669 individuals distributed among 11 populations from Peru. All samples were analyzed using 23 autosomal STR markers. The Arlequin v3.5.2.2 software was used to determine the genetic distances (Fst) of the studied populations. Notable population substructure was detected between some populations.

Genetic ancestry in Afro-descendants from the Andes and Pacific Coast regions of Ecuador

This study aimed to investigate genetic diversity and ancestry in Afro-descendants from the Andes (AN) and the Pacific Coast (PC) regions of Ecuador, using autosomal and lineage markers. CR-mtDNA and PPY23-STRs showed high haplotype diversities. Statistically significant differences were found between AN and PC. Due to different patterns of sex-biased matting, differences between regions were more pronounced for the mtDNA than for the Y-chromosomal markers. A lower African ancestry was detected in AN than PC, for autosomal and both maternal and paternal lineage markers.

Social injustice unveiled by genetic analysis: Argentina as a case study.

The population of the American countries is genetically heterogeneous, whose genesis result from of recent admixture events. In this process, the transoceanic European component displaced the original inhabitants of the continent. To investigate whether socially differentiated cohorts exhibit underlying ancestry components within an urban admixed population, two cohorts of individuals inhabiting Argentina were studied. One cohort included genetically unrelated individuals involved in voluntary paternity testing while the other included sexual or blood-crime suspects. We analyzed over 2500 unrelated individuals: four Native American maternal lineage mtDNA markers in 1024 samples, five Y chromosome haplogroups in 658 male samples, 24 autosomal ancestry informative markers (AIMs) in 205 samples, and 15 autosomal short tandem repeats (STRs) in 1557 samples; countrywide and divided by regions. While our results confirm a tricontinental ethnic contribution to both cohorts, their proportions showed statistically significant differences, with a higher proportion of Native American ancestry in the cohort linked to violent crimes compared to those in paternity testing. This hallmark was observed with all the marker sets used and at various levels of analysis. Since paternity tests are costly, socio-economic differences might help to interpret our observations. The effect of discrimination against descendants of Native American minorities, and exposure to violent social environments, might link marginal groups to criminality. Our findings underscore the relevance of proper social management since only by improving living conditions, reducing discrimination, promoting education, and providing job opportunities will it be possible to attain equality in a heterogeneous society. Genetic markers proved to be highly informative in unveiling unexpected social differences.