The ReAct (Recovery, Activity) project is an ENFSI (European Network of Forensic Science Institutes) supported initiative comprising a large consortium of laboratories. Here, the results from more than 23 laboratories are presented. The primary purpose was to design experiments simulating typical casework circumstances; collect data and to implement Bayesian networks to assess the value (i.e., likelihood ratio) of DNA results given activity level propositions. Two different experimental designs were used to simulate a robbery, where a screwdriver was used to force a door or window. Propositions and case information were chosen following laboratory feedback listing typical casework circumstances (included in the paper). In a direct transfer experiment, the defendant owned and used the screwdriver, but he did not force the door/window in question. An unknown person used the defendant's stolen screwdriver. In an indirect transfer experiment, the defendant neither owned, saw, nor used the screwdriver, nor did they force the door or window. For the second experiment, given the defence view, the defendant never held the screwdriver. We envisaged the situation where an object manipulated by the defendant (or the defendant himself/herself) would be touched by the unknown offender who would then force the window. It was found for the direct transfer experiment that unless a single contributor profile aligning with the known person's of interest profile was retrieved, the results did not allow to discriminate between propositions. On the other hand, for the indirect transfer experiment, both single and major contributor profiles that aligned with the person of interest (POI) supported the proposition that the person used the tool rather than an unknown person who had touched an object, when indeed the former was true. There was considerable variation in median recoveries of DNA between laboratories (between 200pg-5ng) for a given experiment if quantities are taken into account. These differences affect the likelihood ratios given activity level propositions. More than 2700 samples were analysed in the course of this study. Two different Bayesian Networks are made available via an open source application written in Shiny R: Shiny_React(). For comparison, all datasets were analysed using a qualitative method categorised into absent, single, major or other given contributors. The importance of standardising methods is emphasised, alongside the necessity of developing new approaches to assign the probability of laboratory-dependent DNA recovery. Freely accessible open databases play a crucial role in supporting these efforts.
- Klíčová slova
- Activity level, Bayesian networks, DNA direct and indirect transfer, Open access databases, ReAct project, Reproducibility,
- MeSH
- Bayesova věta * MeSH
- DNA fingerprinting * MeSH
- DNA * genetika MeSH
- laboratoře * MeSH
- lidé MeSH
- mikrosatelitní repetice MeSH
- pravděpodobnostní funkce MeSH
- soudní genetika metody MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- DNA * MeSH
BACKGROUND: Structural variants (SVs) represent an important source of genetic variation. One of the most critical problems in their detection is breakpoint uncertainty associated with the inability to determine their exact genomic position. Breakpoint uncertainty is a characteristic issue of structural variants detected via short-read sequencing methods and complicates subsequent population analyses. The commonly used heuristic strategy reduces this issue by clustering/merging nearby structural variants of the same type before the data from individual samples are merged. RESULTS: We compared the two most used dissimilarity measures for SV clustering in terms of Mendelian inheritance errors (MIE), kinship prediction, and deviation from Hardy-Weinberg equilibrium. We analyzed the occurrence of Mendelian-inconsistent SV clusters that can be collapsed into one Mendelian-consistent SV as a new measure of dataset consistency. We also developed a new method based on constrained clustering that explicitly identifies these types of clusters. CONCLUSIONS: We found that the dissimilarity measure based on the distance between SVs breakpoints produces slightly better results than the measure based on SVs overlap. This difference is evident in trivial and corrected clustering strategy, but not in constrained clustering strategy. However, constrained clustering strategy provided the best results in all aspects, regardless of the dissimilarity measure used.
- Klíčová slova
- Breakpoints uncertainty problem, Constrained clustering, Mendelian inheritance error, Structural variants, Whole genome sequencing,
- MeSH
- genom lidský * MeSH
- genomika MeSH
- lidé MeSH
- nejistota MeSH
- shluková analýza MeSH
- strukturální variace genomu * MeSH
- vysoce účinné nukleotidové sekvenování MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
OBJECTIVES: The Sahel belt is occupied by populations who use two types of subsistence strategy, nomadic pastoralism and sedentary farming, and who belong to three linguistic families, Niger-Congo, Nilo-Saharan, and Afro-Asiatic. Little is known, however, about the origins of these two populations and their mutual genetic relationships. MATERIALS AND METHODS: We have built a large dataset of mitochondrial DNA sequences and Y chromosomal STR haplotypes of pastoralists and farmers belonging to all three linguistic phyla in the western, central, and eastern parts of the Sahel. We calculated pairwise genetic, geographic, and linguistic distances between populations and analyzed the effects of geography, language, and subsistence on population genetic structure. RESULTS: We found that subsistence mode significantly contributed to the generally low population structure in the Sahel and that language affiliation plays a more important role for pastoralists than for farmers. We also demonstrated that geographic isolation significantly influenced the population structure of sedentary farmers but not of nomadic pastoralists. Finally, we found haplotypes shared between the Fulani and Arabic-speaking Baggara, supporting the theory of Baggarization, which explains the recent adaptation of Arabic-speaking nomads in the Sahel region through contact with autochthonous sub-Saharan populations. CONCLUSIONS: Based on various genetic and archaeological evidence pertaining to the Sahel, we suggest that the idea of a bidirectional Sahelian corridor is valid, but that pastoralists made a more important contribution to its population structure. It is also possible that agropastoralists diverged into farmers and pastoralists in the early stages of formation of the Sahelian gene pool.
- Klíčová slova
- African Sahel, Baggarization, Y chromosome, mtDNA, subsistence,
- MeSH
- genetická variace * MeSH
- kulturní evoluce MeSH
- lidé MeSH
- lidský chromozom Y * MeSH
- migrace lidstva MeSH
- mikrosatelitní repetice * MeSH
- mitochondriální DNA analýza MeSH
- zemědělství klasifikace MeSH
- životní styl * etnologie MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- střední Afrika MeSH
- východní Afrika MeSH
- západní Afrika MeSH
- Názvy látek
- mitochondriální DNA MeSH
The human Y-chromosome has proven to be a powerful tool for tracing the paternal history of human populations and genealogical ancestors. The human Y-chromosome haplogroup Q is the most frequent haplogroup in the Americas. Previous studies have traced the origin of haplogroup Q to the region around Central Asia and Southern Siberia. Although the diversity of haplogroup Q in the Americas has been studied in detail, investigations on the diffusion of haplogroup Q in Eurasia and Africa are still limited. In this study, we collected 39 samples from China and Russia, investigated 432 samples from previous studies of haplogroup Q, and analyzed the single nucleotide polymorphism (SNP) subclades Q1a1a1-M120, Q1a2a1-L54, Q1a1b-M25, Q1a2-M346, Q1a2a1a2-L804, Q1a2b2-F1161, Q1b1a-M378, and Q1b1a1-L245. Through NETWORK and BATWING analyses, we found that the subclades of haplogroup Q continued to disperse from Central Asia and Southern Siberia during the past 10,000 years. Apart from its migration through the Beringia to the Americas, haplogroup Q also moved from Asia to the south and to the west during the Neolithic period, and subsequently to the whole of Eurasia and part of Africa.
- Klíčová slova
- Eurasia, Han Chinese, Haplogroup Q, Multidirectional migrations, Y-chromosome,
- MeSH
- fylogeneze MeSH
- haplotypy genetika MeSH
- jednonukleotidový polymorfismus MeSH
- lidé MeSH
- lidský chromozom Y genetika MeSH
- migrace lidstva * MeSH
- mikrosatelitní repetice genetika MeSH
- populační genetika * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Asie MeSH
- Čína MeSH
- Sibiř MeSH
BACKGROUND: Today, African pastoralists are found mainly in the Sahel/Savannah belt spanning 6,000 km from west to east, flanked by the Sahara to the north and tropical rainforests to the south. The most significant group among them are the Fulani who not only keep cattle breeds of possible West Eurasian ancestry, but form themselves a gene pool containing some paternally and maternally-transmitted West Eurasian haplogroups. MATERIALS AND METHODS: We generated complete sequences for 33 mitogenomes belonging to haplogroups H1 and U5 (23 and 10, respectively), and genotyped 16 STRs in 65 Y chromosomes belonging to haplogroup R1b-V88. RESULTS: We show that age estimates of the maternal lineage H1cb1, occurring almost exclusively in the Fulani, point to the time when the first cattle herders settled the Sahel/Savannah belt. Similar age estimates were obtained for paternal lineage R1b-V88, which occurs today in the Fulani but also in other, mostly pastoral populations. Maternal clade U5b1b1b, reported earlier in the Berbers, shows a shallower age, suggesting another possibly independent input into the Sahelian pastoralist gene pool. CONCLUSIONS: Despite the fact that animal domestication originated in the Near East ∼ 10 ka, and that it was from there that animals such as sheep, goats as well as cattle were introduced into Northeast Africa soon thereafter, contemporary cattle keepers in the Sahel/Savannah belt show uniparental genetic affinities that suggest the possibility of an ancient contact with an additional ancestral population of western Mediterranean ancestry.
- Klíčová slova
- Fulani, Y chromosome, mtDNA, pastoralism, phylogeography,
- MeSH
- antropologie fyzická MeSH
- černoši genetika MeSH
- dějiny starověku MeSH
- fylogeneze MeSH
- haplotypy genetika MeSH
- lidé MeSH
- lidský chromozom Y genetika MeSH
- migrace lidstva dějiny MeSH
- mitochondriální DNA genetika MeSH
- populační genetika MeSH
- zemědělství dějiny MeSH
- Check Tag
- dějiny starověku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- historické články MeSH
- Geografické názvy
- subsaharská Afrika MeSH
- Názvy látek
- mitochondriální DNA MeSH
In a worldwide collaborative effort, 19,630 Y-chromosomes were sampled from 129 different populations in 51 countries. These chromosomes were typed for 23 short-tandem repeat (STR) loci (DYS19, DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393, DYS385ab, DYS437, DYS438, DYS439, DYS448, DYS456, DYS458, DYS635, GATAH4, DYS481, DYS533, DYS549, DYS570, DYS576, and DYS643) and using the PowerPlex Y23 System (PPY23, Promega Corporation, Madison, WI). Locus-specific allelic spectra of these markers were determined and a consistently high level of allelic diversity was observed. A considerable number of null, duplicate and off-ladder alleles were revealed. Standard single-locus and haplotype-based parameters were calculated and compared between subsets of Y-STR markers established for forensic casework. The PPY23 marker set provides substantially stronger discriminatory power than other available kits but at the same time reveals the same general patterns of population structure as other marker sets. A strong correlation was observed between the number of Y-STRs included in a marker set and some of the forensic parameters under study. Interestingly a weak but consistent trend toward smaller genetic distances resulting from larger numbers of markers became apparent.
- Klíčová slova
- AMOVA, Database, Discriminatory power, Gene diversity, Population structure,
- MeSH
- alely MeSH
- haplotypy * MeSH
- lidé MeSH
- lidský chromozom Y * MeSH
- mikrosatelitní repetice * MeSH
- soudní genetika MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
AIM: To evaluate Y-chromosomal diversity of the Moravian Valachs of the Czech Republic and compare them with a Czech population sample and other samples from Central and South-Eastern Europe, and to evaluate the effects of genetic isolation and sampling. METHODS: The first sample set of the Valachs consisted of 94 unrelated male donors from the Valach region in northeastern Czech Republic border-area. The second sample set of the Valachs consisted of 79 men who originated from 7 paternal lineages defined by surname. No close relatives were sampled. The third sample set consisted of 273 unrelated men from the whole of the Czech Republic and was used for comparison, as well as published data for other 27 populations. The total number of samples was 3244. Y-short tandem repeat (STR) markers were typed by standard methods using PowerPlex® Y System (Promega) and Yfiler® Amplification Kit (Applied Biosystems) kits. Y-chromosomal haplogroups were estimated from the haplotype information. Haplotype diversity and other intra- and inter-population statistics were computed. RESULTS: The Moravian Valachs showed a lower genetic variability of Y-STR markers than other Central European populations, resembling more to the isolated Balkan populations (Aromuns, Csango, Bulgarian, and Macedonian Roma) than the surrounding populations (Czechs, Slovaks, Poles, Saxons). We illustrated the effect of sampling on Valach paternal lineages, which includes reduction of discrimination capacity and variability inside Y-chromosomal haplogroups. Valach modal haplotype belongs to R1a haplogroup and it was not detected in the Czech population. CONCLUSION: The Moravian Valachs display strong substructure and isolation in their Y chromosomal markers. They represent a unique Central European population model for population genetics.
- MeSH
- amplifikace genu MeSH
- DNA analýza MeSH
- genetická variace genetika MeSH
- haplotypy MeSH
- lidé MeSH
- lidský chromozom Y genetika MeSH
- mikrosatelitní repetice genetika MeSH
- modely genetické * MeSH
- ochrana genetických informací MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- srovnávací studie MeSH
- Geografické názvy
- Česká republika MeSH
- Názvy látek
- DNA MeSH
Allele frequencies for 17 short tandem repeats (STRs) autosomal loci (D2S1338, D3S1358, D5S818, D7S820, D8S1179, D13S317, D16S539, D18S51, D19S433, D21S11, CSF1PO, FGA, PentaD, PentaE, TH01, TPOX, vWA) were studied in an extensive sample (max. N=1411) of unrelated individuals originating from the Czech Republic. Population and forensic parameters were estimated. Except for FGA and Penta E loci, no deviations from the Hardy-Weinberg equilibrium were detected. A comparative analysis with published data revealed significant differences in allele frequencies for some loci from the Polish population and three Hungarian populations (Ashkenazim population and Romany populations from Debrecen and Baranya County, respectively). A combination of these 17 STR loci provides a powerful tool for forensic identification in the native Czech population.
- MeSH
- DNA fingerprinting MeSH
- frekvence genu * MeSH
- lidé MeSH
- polymerázová řetězová reakce MeSH
- populační genetika * MeSH
- tandemové repetitivní sekvence * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Česká republika MeSH