103 research outputs found

    The multiple maternal legacy of the Late Iron Age group of Urville-Nacqueville (France, Normandy) documents a long-standing genetic contact zone in northwestern France

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    The compilation of archaeological and genetic data for ancient European human groups has provided persuasive evidence for a complex series of migrations, population replacements and admixture until the Bronze Age. If the Bronze-to-Iron Age transition has been well documented archaeologically, ancient DNA (aDNA) remains rare for the latter period and does not precisely reflect the genetic diversity of European Celtic groups. In order to document the evolution of European communities, we analysed 45 individuals from the Late Iron Age (La Tène) Urville-Nacqueville necropolis in northwestern France, a region recognized as a major cultural contact zone between groups from both sides of the Channel. The characterization of 37 HVS-I mitochondrial sequences and 40 haplogroups provided the largest maternal gene pool yet recovered for the European Iron Age. First, descriptive analyses allowed us to demonstrate the presence of substantial amounts of steppe-related mitochondrial ancestry in the community, which is consistent with the expansion of Bell Beaker groups bearing an important steppe legacy in northwestern Europe at approximately 2500 BC. Second, maternal genetic affinities highlighted with Bronze Age groups from Great Britain and the Iberian Peninsula regions tends to support the idea that the continuous cultural exchanges documented archaeologically across the Channel and along the Atlantic coast (during and after the Bronze Age period) were accompanied by significant gene flow. Lastly, our results suggest a maternal genetic continuity between Bronze Age and Iron Age groups that would argue in favour of a cultural transition linked to progressive local economic changes rather than to a massive influx of allochthone groups. The palaeogenetic data gathered for the Urville-Nacqueville group constitute an important step in the biological characterization of European Iron age groups. Clearly, more numerous and diachronic aDNA data are needed to fully understand the complex relationship between the cultural and biological evolution of groups from the period

    New insights on Neolithic food and mobility patterns of Mediterranean coastal populations

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    The aims of this research are to explore the diet, mobility, social organization, and environmental exploitation patterns of early Mediterranean farmers, particularly the role of marine and plant resources in these foodways. In addition, this work strives to document possible gendered patterns of behavior linked to the neolithization of this ecologically rich area. To achieve this, a set of multiproxy analyses (isotopic analyses, dental calculus, microremains analysis, ancient DNA) were performed on an exceptional deposit (n = 61) of human remains from the Les Bréguières site (France), dating to the transition of the sixth to the fifth millennium BCE. Materials and Methods: The samples used in this study were excavated from the Les Bréguières site (Mougins, Alpes-Maritimes, France), located along the southeastern Mediterranean coastline of France. Stable isotope analyses (C, N) on bone collagen (17 coxal bones, 35 craniofacial elements) were performed as a means to infer protein intake during tissue development. Sulfur isotope ratios were used as indicators of geographical and environmental points of origin. The study of ancient dental calculus helped document the consumption of plants. Strontium isotope analysis on tooth enamel (n = 56) was conducted to infer human provenance and territorial mobility. Finally, ancient DNA analysis was performed to study maternal versus paternal diversity within this Neolithic group (n = 30). Results: Stable isotope ratios for human bones range from −20.3 to −18.1¿ for C, from 8.9 to 11.1¿ for N and from 6.4 to 15¿ for S. Domestic animal data range from −22.0 to −20.2¿ for C, from 4.1 to 6.9¿ for N, and from 10.2 to 12.5¿ for S. Human enamel 87Sr/86Sr range from 0.7081 to 0.7102, slightly wider than the animal range (between 0.7087 and 0.7096). Starch and phytolith microremains were recovered as well as other types of remains (e.g., hairs, diatoms, fungal spores). Starch grains include Triticeae type and phytolith includes dicotyledons and monocot types as panicoid grasses. Mitochondrial DNA characterized eight different maternal lineages: H1, H3, HV (5.26%), J (10.53%), J1, K, T (5.2%), and U5 (10.53%) but no sample yielded reproducible Y chromosome SNPs, preventing paternal lineage characterization. Discussion: Carbon and nitrogen stable isotope ratios indicate a consumption of protein by humans mainly focused on terrestrial animals and possible exploitation of marine resources for one male and one undetermined adult. Sulfur stable isotope ratios allowed distinguishing groups with different geographical origins, including two females possibly more exposed to the sea spray effect. While strontium isotope data do not indicate different origins for the individuals, mitochondrial lineage diversity from petrous bone DNA suggests the burial includes genetically differentiated groups or a group practicing patrilocality. Moreover, the diversity of plant microremains recorded in dental calculus provide the first evidence that the groups of Les Bréguières consumed a wide breadth of plant foods (as cereals and wild taxa) that required access to diverse environments. This transdisciplinary research paves the way for new perspectives and highlights the relevance for novel research of contexts (whether recently discovered or in museum collections) excavated near shorelines, due to the richness of the biodiversity and the wide range of edible resources available

    Authenticated DNA from Ancient Wood Remains

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    • Background The reconstruction of biological processes and human activities during the last glacial cycle relies mainly on data from biological remains. Highly abundant tissues, such as wood, are candidates for a genetic analysis of past populations. While well-authenticated DNA has now been recovered from various fossil remains, the final ‘proof' is still missing for wood, despite some promising studies. • Scope The goal of this study was to determine if ancient wood can be analysed routinely in studies of archaeology and palaeogenetics. An experiment was designed which included blind testing, independent replicates, extensive contamination controls and rigorous statistical tests. Ten samples of ancient wood from major European forest tree genera were analysed with plastid DNA markers. • Conclusions Authentic DNA was retrieved from wood samples up to 1000 years of age. A new tool for real-time vegetation history and archaeology is ready to us

    Investigating mitochondrial DNA relationships in Neolithic Western Europe through serial coalescent simulations

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    Recent ancient DNA studies on European Neolithic human populations have provided persuasive evidence of a major migration of farmers originating from the Aegean, accompanied by sporadic hunter-gatherer admixture into early Neolithic populations, but increasing toward the Late Neolithic. In this context, ancient mitochondrial DNA data collected from the Neolithic necropolis of Gurgy (Paris Basin, France), the largest mitochondrial DNA sample obtained from a single archeological site for the Early/Middle Neolithic period, indicate little differentiation from farmers associated to both the Danubian and Mediterranean Neolithic migration routes, as well as from Western European hunter-gatherers. To test whether this pattern of differentiation could arise in a single unstructured population by genetic drift alone, we used serial coalescent simulations. We explore female effective population size parameter combinations at the time of the colonization of Europe 45000 years ago and the most recent of the Neolithic samples analyzed in this study 5900 years ago, and identify conditions under which population panmixia between hunter-gatherers/Early-Middle Neolithic farmers and Gurgy cannot be rejected. In relation to other studies on the current debate of the origins of Europeans, these results suggest increasing hunter-gatherer admixture into farmers' group migrating farther west in Europe.European Journal of Human Genetics advance online publication, 28 December 2016; doi:10.1038/ejhg.2016.180

    Origin and mobility of Iron Age Gaulish groups in present-day France revealed through archaeogenomics

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    The Iron Age period occupies an important place in French history, as the Gauls are regularly presented as the direct ancestors of the extant French population. We documented here the genomic diversity of Iron Age communities originating from six French regions. The 49 acquired genomes permitted us to highlight an absence of discontinuity between Bronze Age and Iron Age groups in France, lending support to a cultural transition linked to progressive local economic changes rather than to a massive influx of allochthone groups. Genomic analyses revealed strong genetic homogeneity among the regional groups associated with distinct archaeological cultures. This genomic homogenisation appears to be linked to individuals’ mobility between regions as well as gene flow with neighbouring groups from England and Spain. Thus, the results globally support a common genomic legacy for the Iron Age population of modern-day France that could be linked to recurrent gene flow between culturally differentiated communities

    Ten millennia of hepatitis B virus evolution

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    Hepatitis B virus (HBV) has been infecting humans for millennia and remains a global health problem, but its past diversity and dispersal routes are largely unknown. We generated HBV genomic data from 137 Eurasians and Native Americans dated between ~10,500 and ~400 years ago. We date the most recent common ancestor of all HBV lineages to between ~20,000 and 12,000 years ago, with the virus present in European and South American hunter-gatherers during the early Holocene. After the European Neolithic transition, Mesolithic HBV strains were replaced by a lineage likely disseminated by early farmers that prevailed throughout western Eurasia for ~4000 years, declining around the end of the 2nd millennium BCE. The only remnant of this prehistoric HBV diversity is the rare genotype G, which appears to have reemerged during the HIV pandemic

    Traçabilité des bois de chêne (méthodes moléculaires et applications)

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    Que ce soit en réponse à des inquiétudes d'ordre phytosanitaire, commercial, légal ou encore dans le cadre de l' écocertification, de nombreux acteurs de la filière forestière souhaiteraient que soit mise au point une technique fiable permettant de contrôler l'origine des bois. Au cours de cette étude, nous avons donc développé des marqueurs moléculaires utilisables sur ADN extrait de bois de chêne. Les données acquises sur la variabilité de l'ADN chloroplastique des chênes blancs européens ont permis de réaliser une cartographie très fine de cette variabilité, caractérisée par une très forte structuration géographique des variants sur le continent européen. C'est cette information qui permettait d'envisager des applications en matière de traçabilité, dès lors que les techniques moléculaires pouvaient être transposées sur bois. Ce travail se décompose donc en trois études successives. (1) La première étude a consisté à définir les potentialités du matériau bois pour des analyses moléculaires. L'ADN issu de ce matériau apparaît largement dégradé et en très faible quantité, et nous avons clairement montré que le taux de succès de génotypage est plus important quand nous travaillons sur de l'aubier frais, et quand les séquences ciblées sont courtes et présentes en de nombreuses copies dans la cellule. (2) L'étape suivante a consisté à mettre au point des méthodes moléculaires permettant de caractériser les haplotypes sur bois: l'analyse de cinq combinaisons PCR-RFLP constitue la clé de notre méthode. Nous sommes donc aujourd'hui capables de contrôler statistiquement la conformité des haplotypes identifiés sur un lot de bois avec ceux trouvés dans la région d'origine. La recherche de nouveaux polymorphismes, permettant de distinguer des régions françaises ou européennes, a également été amorcée. De nouvelles combinaisons PCR-RFLP polymorphes ont été identifiées. De plus, les microsatellites chloroplastiques pourraient permettre d'automatiser le génotypage. Enfin, les données sur la variabilité des microsatellites chloroplastiques ont permis d'initier une étude sur l'évolution moléculaire de ces marqueurs. Une relation nette entre la variabilité observée et le nombre de répétitions rencontrées au sein de ces motifs a été mise en évidence ; cette information doit être prise en compte dans la comparaison des niveaux de diversité entre différentes espèces. (3) La dernière partie de ce travail relate deux applications des méthodes de typage génétique des bois de chêne. La première application concerne le secteur de la tonnellerie française, où nos outils permettent de contrôler l'origine géographique des bois utilisés pour la fabrication des barriques; la seconde concerne des études de paléogénétique, où le typage de bois archéologiques permet de mieux appréhender l'action de 1 'Homme sur la diversité et la structuration des populations de chêne.In response to phytosanitary, commercial, legal or ecocertification concerns, numerous actors of the forestry industry are looking for a reliable technique permitting to control wood origin. ln this study, molecular markers adapted to the analysis of oak wood were developed. The important database on chloroplast DNA variability of European white oaks has allowed to precisely map this variation, which is characterised by a strong geographical structure throughout the European continent. This work is divided in three steps. (i) First, the potential of dry wood for genetic analyses was defined. The DNA isolated from wood is largely degraded and present in low amounts. Genotyping sucess rates increase on fresh sapwood and if targeted sequences are short and present in high copy number per ceIl. (2) Second, molecular methods were developed to characterise wood haplotypes. Five different PCR-RFLP combinations can be used for that purpose. They allow to check statistically the conformity of the haplotypes detected on wood samples with those encountered in the hypothetical region of origin. A new search for polymorphism bas been conducted in order to better distinguish French or European regions. Some new PCR-RFLP combinations allowed to detect additional variation in Franœ, whereas chloroplast microsatellites were designed that could permit the automation of genotyping procedures. Finally, the collection of chloroplast microsatellites variability data allowed us to initiate a study of their evolution. A clear relation between level of variation and microsatellite length has been demonstrated, which should be taken into account in interspecific comparisons. (3) The last study conccrned two different applications of these molecular methods for wood genotyping. The first is an industrial application: the method was adapted to the control the geographical origin of oak wood used to make barrels. The second is in the field of paleogenetics and archaeology: the typing of ancient oak wood allowed to better understand the action of Man on oak populations and the past use of this resource.NANCY1-SCD Sciences & Techniques (545782101) / SudocSudocFranceF

    Ancient DNA : a window to the past of Europe

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    Ancient DNA : a window to the past of Europe

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    International audienc
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