Recent developments in High-Throughput DNA sequencing (HTS) technologies and ancient DNA (aDNA) research have opened access to the characterization of the microbial communities within past populations. Most studies have, however, relied on the analysis of dental calculus as one particular material type particularly prone to the molecular preservation of ancient microbial biofilms and potential of entire teeth for microbial characterization, both of healthy communities and pathogens in ancient individuals, remains overlooked. In this study, we used shotgun sequencing to characterize the bacterial composition from historical subjects showing macroscopic evidence of oral pathologies. We first carried out a macroscopic analysis aimed at identifying carious or periodontal diseases in subjects belonging to a French rural population of the 18th century AD. We next examined radiographically six subjects showing specific, characteristic dental pathologies and applied HTS shotgun sequencing to characterize the microbial communities present in and on the dental material. The presence of Streptococcus mutans and also Rothia dentocariosa, Actinomyces viscosus, Porphyromonas gingivalis, Tannerella forsythia, Pseudoramibacter alactolyticus, Olsenella uli and Parvimonas micra was confirmed through the presence of typical signatures of post-mortem DNA damage at an average depth-of-coverage ranging from 0.5 to 7X, with a minimum of 35% (from 35 to 93%) of the positions in the genome covered at least once. Each sampled tooth showed a specific bacterial signature associated with carious or periodontal pathologies. This work demonstrates that from a healthy independent tooth, without visible macroscopic pathology, we can identify a signature of specific pathogens and deduce the oral health status of an individual.

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European genetic ancestry originates from three main ancestral populations - Western hunter-gatherers, early European farmers and Yamnaya Eurasian herders - whose edges geographically met in present-day France. Despite its central role to our understanding of how the ancestral populations interacted and gave rise to modern population structure, the population history of France has remained largely understudied. Here, we analysed 856 high-coverage whole-genome sequences along with genome-wide genotyping data of 3,234 present-day individuals from the northern half of France and merged them with publicly available present-day and ancient Europe-wide genotype datasets. We also analysed, for the first time, the whole-genome sequences of six medieval individuals (300-1100 CE) from Western France to gain insights into the genetic impact of what is commonly known as the Migration Period in Europe. We found extensive fine-scale population structure across Brittany and the downstream Loire basin, emphasizing the need for investigating local populations to better understand the distribution of rare and putatively deleterious variants across space. Overall, we observed an increased population differentiation between the northern and southern sides of the river Loire, which are characterised by different proportions of steppe vs. Neolithic-related ancestry. Samples from Western Brittany carry the largest levels of steppe ancestry and show high levels of allele sharing with individuals associated with the Bell Beaker complex, levels that are only comparable with those found in populations lying on the northwestern edges of Europe. Together, our results imply that present-day individuals from Western Brittany retain substantial legacy of the genetic changes that occurred in Northwestern Europe following the arrival of the Bell Beaker people c. 2500 BCE. Such genetic legacy may explain the sharing of disease-related alleles with other present-day populations from Western Britain and Ireland.

History and Archaeology of the Commandery-Great Priory of the Hospitallers of St John in Toulouse. Research Inventory. The commandery (which later became a great priory) of the Hospitallers of St John of Jerusalem in Toulouse, which has just become the seat of the Direction régionale des affaires culturelles de Midi-Pyrénées, is the subject of a diachronic and multidisciplinary research programme carried out in parallel and in together with a preventive dig. The research based on archives started in 2000 and the field operations, carried out between 2003 and 2005, are currently being reported. The present paper is only a stage in the reflection and relies on the crossing of all kinds of data. It favours the topographic and architectural dimensions of the urban commandery as well as the burial grounds, on which the dig of a cloister gallery with its funeral recesses and that of the cemetery have thrown light. Issues regarding burial places (chronology, hierarchy and layout) will be tackled, as well as burial methods and practices and the way people were selected to burial (lay and religious, prestigious or not, children, pilgrims etc.), so as to allow a reflection on the social dimension of death around the Hospitallers in Toulouse.

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