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Studies on the impact of ocean acidification on marine organisms involve exposing organisms to future acidification scenarios as projected for open ocean, which has limited relevance for coastal calcifiers. Characterization of reaction norms across a range of pH and identification of tipping points beyond which detrimental effects are observed has been limited and focus on only a few macro-physiological traits. Here we filled this knowledge gap by developing a framework to analyze the broad macro-physiological and molecular responses over a wide pH range of juvenile Pacific oyster, a model species for which the tolerance threshold to acidification remains unknown. We identify low tipping points for physiological traits at pH 7.3-6.9 that coincide with a major reshuffling in membrane lipids and transcriptome. In contrast, shell parameters exhibit effects with pH drop well before tipping points, likely impacting animal fitness. These findings were made possible by the development of an innovative methodology to synthesize and identify the main patterns of variations in large -omic datasets, fit them to pH and identify molecular tipping-points. We propose the application of our framework broadly to the assessment of effects of global change on other organisms.

The intensification of warming-induced mass-mortalities in invertebrate populations is a critical phenomenon that affects many regions worldwide, including temperate ones. Mesophotic zones (from 30 to 150 meters depth) have been hypothesized to provide refuge from climate change to gorgonian populations, a promise for re-seeding damaged or destroyed shallow populations. Using a proteomic approach, we investigated the responses and acclimatization ability of the yellow gorgonian Eunicella cavolini along an environmental gradient following reciprocal transplantations between shallow (20m) and mesophotic (70m) zones. Our results suggested that yellow gorgonians from mesophotic waters exhibit a more plastic response when transplanted into shallow waters, compared to shallow gorgonians when placed at 70m. Colonies transplanted from mesophotic to shallow waters presented a down-regulation of immune response compared to colonies that stayed at 70m. Despite immunodepression, transplanted colonies displayed no signs of necrosis or apoptosis, underscoring the potential acclimation capacity of mesophotic populations. Under future climate change scenarios, Eunicella cavolini populations could thus exhibit physiological plasticity in the face of environmental stress, suggesting that no physiological barrier may limit natural colonization from mesophotic populations. This analysis provides new insights into the cellular and molecular responses of gorgonians to environmental changes.

Modern humans have populated Europe for more than 45,000 years1,2. Our knowledge of the genetic relatedness and structure of ancient hunter-gatherers is however limited, owing to the scarceness and poor molecular preservation of human remains from that period3. Here we analyse 356 ancient hunter-gatherer genomes, including new genomic data for 116 individuals from 14 countries in western and central Eurasia, spanning between 35,000 and 5,000 years ago. We identify a genetic ancestry profile in individuals associated with Upper Palaeolithic Gravettian assemblages from western Europe that is distinct from contemporaneous groups related to this archaeological culture in central and southern Europe4, but resembles that of preceding individuals associated with the Aurignacian culture. This ancestry profile survived during the Last Glacial Maximum (25,000 to 19,000 years ago) in human populations from southwestern Europe associated with the Solutrean culture, and with the following Magdalenian culture that re-expanded northeastward after the Last Glacial Maximum. Conversely, we reveal a genetic turnover in southern Europe suggesting a local replacement of human groups around the time of the Last Glacial Maximum, accompanied by a north-to-south dispersal of populations associated with the Epigravettian culture. From at least 14,000 years ago, an ancestry related to this culture spread from the south across the rest of Europe, largely replacing the Magdalenian-associated gene pool. After a period of limited admixture that spanned the beginning of the Mesolithic, we find genetic interactions between western and eastern European hunter-gatherers, who were also characterized by marked differences in phenotypically relevant variants. Ancient DNA data generation Before the LGM LGM in southwestern and western Europe Post-LGM in the Italian peninsula Post-LGM in western and central Europe Post-14 ka to Neolithic Phenotypically relevant variants Discussion and conclusions Methods

Human activities induce direct or indirect selection pressure on natural population and may ultimately affect population's integrity. While numerous conservation programs aimed to minimize human‐induced genomic variation, human‐induced environmental variation may generate epigenomic variation potentially affecting fitness through phenotypic modifications. Major questions remain pertaining to how much epigenomic variation arises from environmental heterogeneity, whether this variation can persist throughout life, and whether it can be transmitted across generations. We performed whole genome bisulfite sequencing (WGBS) on the sperm of genetically indistinguishable hatchery and wild‐born migrating adults of Coho salmon (Oncorhynchus kisutch) from two geographically distant rivers at different epigenome scales. Our results showed that coupling WGBS with fine‐scale analyses (local and chromosomal) allows the detection of parallel early‐life hatchery‐induced epimarks that differentiate wild from hatchery‐reared salmon. Four chromosomes and 183 differentially methylated regions (DMRs) displayed a significant signal of methylation differentiation between hatchery and wild‐born Coho salmon. Moreover, those early‐life epimarks persisted in germ line cells despite about 1.5 year spent in the ocean following release from hatchery, opening the possibility for transgenerational inheritance. Our results strengthen the hypothesis that epigenomic modifications environmentally induced during early‐life development persist in germ cells of adults until reproduction, which could potentially impact their fitness.

International audience; In living organisms, calcium carbonate biomineralization combines complex bio-controlled physical and chemical processes to produce crystalline hierarchical hard tissues (usually calcite or aragonite) typically from an amorphous precursor phase. Understanding the nature of the successive transient amorphous phases potentially involved in the amorphous-to-crystalline transition requires characterization tools, which are able to provide a spatial and spectroscopic analysis of the biomineral structure. In this work, we present a highly sensitive coherent Raman microscopy approach, which allows one to image molecular bond concentrations in post mortem shells and living animals, by exploiting the vibrational signature of the different carbonates compounds. To this end, we target the nu_1 calcium carbonate vibration mode and produce spatially and spectroscopically resolved images of the shell border of a mollusk shell, the Pinctada margaritifera pearl oyster. A novel approach is further presented to efficiently compare the amount of amorphous carbonate with respect to its crystalline counterpart. Finally, the whole microscopy method is used to image in vivo the shell border and demonstrate the feasibility and the reproducibility of the technique. These findings open chemical imaging perspectives for the study of biogenic and bio-inspired crystals.

La grotte de La Marche est bien connue pour son art, en particulier les blocs gravés de figures animales et humaines. À la fin des années 30, L. Péricard et S. Lwoff, puis L. Pradel dans les années 50, ont découvert plusieurs restes humains qu’ils ont attribués au Magdalénien. Entre 1988 et 1993, la réévaluation stratigraphique et le tamisage des déblais réalisés par J. Airvaux a livré de nouveaux restes humains : un fragment de pariétal, quatre fragments de mandibules d’adultes et d’enfants et 35 dents isolées. La datation directe d’une de ces dents isolées confirme une attribution au Magdalénien moyen ancien. Dans cette étude, nous décrivons les dents humaines magdaléniennes de la grotte de La Marche découvertes lors du tamisage par J. Airvaux. Cette série est composée de 49 dents permanentes et déciduales (35 dents isolées et 14 dents incluses sur les fragments mandibulaires) qui représentent un nombre minimum de neuf individus, incluant trois adultes et six immatures. Les dimensions dentaires de La Marche se placent dans la variabilité des échantillons de comparaison datés du Paléolithique supérieur et de l’Holocène, mais montrent un signal contrasté selon les types de dents. La grotte de La Marche est ainsi un des sites magdaléniens européens ayant livré le plus grand nombre de restes humains. Cette série de vestiges fournit de nouvelles données paléobiologiques et enrichit nos connaissances sur la variabilité dentaire des populations contemporaines du Magdalénien moyen. The cave of La Marche is well known for its rock art, especially engraved blocks of animal and human figures. At the end of the ‘30s L. Péricard and S. Lwoff, and then L. Pradel in the ‘50s, discovered several human remains that were attributed to the Magdalenian. Between 1988 and 1993, the stratigraphic reassessment and the sieving of previous backdirt made by J. Airvaux yielded new human remains: a fragment of parietal bone, four mandibular fragments from immature and adult individuals, and 35 isolated teeth. The direct dating of an isolated human tooth confirms the attribution to the Early Middle Magdalenian. In this study, we describe the Magdalenian human teeth from La Marche discovered during the reassessment made by J. Airvaux. This collection is composed of 49 permanent and deciduous teeth (35 isolated teeth and 14 teeth included in mandibular fragments) and represent a minimum number of nine individuals, including three adults and six immature individuals. The dental dimensions of La Marche are included in the variability shown by the comparative samples dated from the Upper Palaeolithic and Holocene, but show a contrasted signal between tooth types. The cave of La Marche is one of the European Magdalenian sites with the largest number of human remains. This collection provides new paleobiological data and extends our knowledge on the dental variability of Middle Magdalenian populations.

Ocean warming challenges marine organisms' resilience, especially for species experiencing temperatures close to their upper thermal limits. A potential increase in thermal tolerance might significantly reduce the risk of population decline, which is intrinsically linked to variability in local habitat temperatures. Our goal was to assess the plastic and genetic potential of response to elevated temperatures in a tropical bivalve model, Pinctada margaritifera. We benefit from two ecotypes for which local environmental conditions are characterized by either large diurnal variations in the tide pools (Marquesas archipelago) or low mean temperature with stable to moderate seasonal variations (Gambier archipelago). We explored the physiological basis of individual responses to elevated temperature, genetic divergence as well as plasticity and acclimation by combining lipidomic and transcriptomic approaches. We show that P. margaritifera has certain capacities to adjust to long-term elevated temperatures that was thus far largely underestimated. Genetic variation across populations overlaps with gene expression and involves the mitochondrial respiration machinery, a central physiological process that contributes to species thermal sensitivity and their distribution ranges. Our results present evidence for acclimation potential in P. margaritifera and urge for longer term studies to assess populations resilience in the face of climate change.Le réchauffement des océans remet en question la résilience des organismes marins, en particulier pour les espèces connaissant des températures proches de leurs limites thermiques supérieures. Une augmentation potentielle de la tolérance thermique pourrait ainsi réduire considérablement le risque de déclin de la population. L'objectif de cette étude était d'évaluer le potentiel plastique et génétique de la réponse à l'exposition courte et chronique à températures élevées chez une espèce de bivalve tropical, Pinctada margaritifera. Ce modèle bénéficie de l'existence de deux écotypes pour lesquels les conditions environnementales locales sont caractérisées soit par de fortes variations diurnes associées aux marées (archipel des Marquises) soit par une température moyenne plus basse et des variations saisonnières prononcées (archipel des Gambier). Nous avons exploré les bases physiologiques des réponses individuelles ainsi que la divergence génétique et quantifié la plasticité en combinant des approches lipidomique et transcriptomique. Nous montrons que P. margaritifera possède des capacités d'acclimatation à des températures élevées sur le long terme jusqu'à présent largement sous-estimées. La divergence génétique entre populations est par ailleurs associée à des différences d'expression des gènes et implique la machinerie respiratoire mitochondriale, un processus physiologique central qui contribue à la sensibilité thermique des espèces et à leurs répartitions. Nos résultats présentent les bases des potentiels d'acclimatation chez P. margaritifera et soulignent l'importance d'études à plus long terme pour évaluer la résilience des populations face au changement climatique.

La présence internationale qu’incarnent les Français établis à l’étranger représente un atout pour la France. En filigrane des mesures déployées à leur attention, les objectifs d’influence que poursuit l’État concurrencent parfois les objectifs d’accompagnement affichés. Pensé dans une optique moderne et universaliste, le dispositif d’encadrement aborde la population établie hors de France selon une image valorisable sur laquelle capitaliser pour la poursuite d’un objectif de soft power. L’émigration française à Londres, autrefois aristocratique ou bourgeoise s’est démocratisée et la recomposition sociale de l’expatriation qui se traduit aujourd’hui dans les parcours professionnels révèle le manquement des dispositifs institutionnels à leur mission d’encadrement des citoyens. The international presence embodied by French nationals living abroad is an asset for France. Underlying the measures deployed for them, the objectives of influence pursued by the nation-state sometimes compete with the objectives of support for the population. Designed from a modern and universalist perspective, the public policies are based on a valuable image of the population established abroad that can be used to capitalise on the pursuit of a soft power agenda. French emigration in London, once aristocratic or bourgeois, has become more democratic, and the social recomposition of expatriation, which reflects in professional careers, reveals the failure of institutional mechanisms to fulfill their mission of providing an inclusive support system for citizens.

Human activities and resource exploitation led to a massive decline of wild salmonid populations, consequently, numerous conservation programs have been developed to supplement wild populations. However, many studies documented reduced fitness of hatchery-born relative to wild fish. Here, by using both RNA sequencing and Whole Genome Bisulfite Sequencing of hatchery and wild-born adult Coho salmon (Oncorhynchus kisutch) originating from two previously studied river systems, we show that early-life hatchery-rearing environment-induced significant and parallel gene expression differentiation is maintained until Coho come back to their natal river for reproduction. A total of 3,643 genes differentially expressed and 859 coexpressed genes were downregulated in parallel in hatchery-born fish from both rivers relative to their wild congeners. Among those genes, 26 displayed a significant relationship between gene expression and the median gene body methylation and 669 single CpGs displayed a significant correlation between methylation level and the associated gene expression. The link between methylation and gene expression was weak suggesting that DNA methylation is not the only player in mediating hatchery-related expression differences. Yet, significant gene expression differentiation was observed despite 18 months spent in a common environment (i.e., the sea). Finally, the differentiation is observed in parallel in two different river systems, highlighting the fact that early-life environment may account for at least some of the reduced fitness of the hatchery salmon in the wild. These results illustrate the relevance and importance of considering both epigenome and transcriptome to evaluate the costs and benefits of large-scale supplementation programs.

In order to supplement and develop the teaching of anesthesia at the Alfort Veterinary School (EnvA), a pedagogical program has been designed for the learning of the steps required to prepare a gaseous anesthesia. This course has been conceived with a special emphasis on the anesthetic machine checklist. Indeed, to carry out an effective and safe anesthesia, it is essential to know how it works, being both a central piece of anesthetics and yet a major source of incident. This work led to the production of a course composed of 10 simulation workshops, set up in the "Vetsims" room of EnvA. The first 7 workshops allow students to discover the machine and its checklist. The course continues with simulation exercises to learn intravenous catheterisation, check of endotracheal tubes integrity and endotracheal intubation. Then, students are asked to sum up the theoretical knowledge acquired during the simulation program, through an interactive e-learning course. Finally, students are encouraged to reflect on the following steps of the anesthetic process through an online self-assessment exercise (from a thesis put together in 2020 by G. Lapertot). Students are guided in their pedagogical program by a poster summarizing each step and allowing an introduction of the importance of the checklist as a cognitive aid. This pedagogical program offers many learning materials : procedural simulations, written classes, self-assessment exercises and instructional videos. The reason to use simulation as a major pedagogical tool for this program is to be consistent with the General Council for Food, Agriculture and Rural Areas’ recommendation of supporting the development of simulation in the french veterinary education. This pedagogical program is in no way intended to replace practice in real conditions. However, it was thought to enhance the acquisition of both theoretical and kinesthetic skills, at a level expected for graduate veterinarians while being compliant with the "Never the first time on the patient" requirement, promoted by both human and veterinary medicines as part of the "One Health" approach.; Dans l'objectif de compléter et d'enrichir l'enseignement de l'anesthésie à l'École nationale vétérinaire d'Alfort, un parcours pédagogique a été créé pour l'apprentissage des étapes nécessaires à préparation d'une anesthésie gazeuse. Ce parcours a été conçu en mettant l'accent sur les vérifications de la machine d'anesthésie. En effet, pour pratiquer une anesthésie gazeuse efficace et sécuritaire, il est indispensable de comprendre le fonctionnement de cet appareil, qui est à la fois une pièce maitresse de l'anesthésie volatile et une source majeure d'incidents. Ce travail a abouti à un parcours composé de 10 ateliers de simulation, installés dans la salle Vetsims de l'EnvA. Les 7 premiers ateliers permettent aux étudiants de se familiariser avec la machine d'anesthésie et ses vérifications. Le parcours se poursuit par la simulation de la pose de cathéter intraveineux, de la vérification de l'intégrité des sondes endotrachéales et de l'intubation endotrachéale. Ensuite, les étudiants sont amenés à faire la synthèse des connaissances théoriques acquises, au sein d'un parcours de e-learning interactif. Enfin, les étudiants sont encouragés à s'interroger sur la suite de la prise en charge anesthésique du cas clinique ayant servi de contexte à ce parcours, à travers un cas clinique en ligne (résultat d'une thèse soutenue en 2020 par G. Lapertot). Les étudiants sont guidés dans ce parcours par un poster exposant chaque étape, permettant également la sensibilisation des étudiants au concept de la check-list comme aide cognitive. Ce programme pédagogique utilise ainsi de nombreux supports d'apprentissage : simulations procédurales, cours écrits, exercices d'auto-évaluations et vidéos didactiques. La position centrale de la simulation comme support de ce parcours a été choisie pour s'accorder avec les recommandations du Conseil Général de l'Alimentation, de l'Agriculture et des Espaces Ruraux, promouvant le développement de la simulation dans l'enseignement vétérinaire. Ce parcours n'est aucunement destiné à remplacer la pratique en conditions réelles. Néanmoins, il a été pensé pour favoriser l'acquisition de compétences théoriques et kinesthésiques, attendues chez les vétérinaires diplômés, tout en respectant l'exigence « Jamais la première fois sur le patient » établie comme doctrine en médecine humaine et vétérinaire réunies au sein du nouveau concept de « One Health » (« Une seule santé »).

Territoire, territorialité et représentation : face à des notions plus que jamais polysémiques et polymorphes, géographes, juristes et politistes s’associent peur montrer que si entre mondialisation et fragmentation, l’Etat comme unité territoriale d’espace souverain est concurrencé par d’autres producteurs de normes, le principe territorial résiste et tend même à se renouveler. Ce renouvellement se concrétise par la prolifération de périmètres et de réseaux plus eu moins institutionnalisés et formalisés, à tous les échelons, sub-, trans- ou supra-nationaux Mais cette prolifération et cet enchevêtrement ne permettent pas toujours de légitimer leurs représentants ni de construire socialement des identités vécues Beaucoup de territoires ne deviennent ni des objets de représentation ni des référents identitaires. Il existe dès lots une crise de légitimité politique qui touche aussi, voire surtout, l’Union européenne, matérialisée par ses frontières extérieures : la crise est non seulement Interne, mais également externe, le mythe européen ayant laissé place à un grand vide en matière de représentation positive de l’idée européenne.

En 2017, 1,8 million d’individus figurent au registre des Français résidant hors de France. Ce chiffre, répertorié tous les ans depuis 1961 par le ministère des Affaires étrangères, est en constante augmentation. Les années 1990 marquent une accentuation de ce phénomène. L’expatriation des Français s’accroît. Par leur citoyenneté, par le lien qu’ils maintiennent avec les institutions, l’émigration des Français est susceptible de représenter un atout, car elle offre à la France une représentat...

The western Mesoamerica was the place of several human displacements and cultural exchanges. During the Middle Postclassic Period (1200-1450 AD), in the Zacapu basin (located in the NW of the actual state of Michoacán), large urban centers developed, resulting in an increase of the human population. Some hypotheses link this demographic growth to the arrival and the settlement of a new population and likely contributed to the development of these sites. In order to test whether a new populati...

Background Tenacibaculum maritimum is a fish pathogen known for causing serious damage to a broad range of wild and farmed marine fish populations worldwide. The recently sequenced genome of T. maritimum strain NCIMB 2154T provided unprecedented information on the possible molecular mechanisms involved in the virulence of this species. However, little is known about the dynamic of infection in vivo, and information is lacking on both the intrinsic host response (gene expression) and its associated microbiota. Here, we applied complementary omic approaches, including dual RNAseq and 16S rRNA gene metabarcoding sequencing using Nanopore and short-read Illumina technologies to unravel the host–pathogen interplay in an experimental infection system using the tropical fish Platax orbicularis as model. Results We showed that the infection of the host is characterised by an enhancement of functions associated with antibiotic and glucans catabolism functions but a reduction of sulfate assimilation process in T. maritimum. The fish host concurrently displays a large panel of immune effectors, notably involving innate response and triggering acute inflammatory response. In addition, our results suggest that fish activate an adaptive immune response visible through the stimulation of T-helper cells, Th17, with congruent reduction of Th2 and T-regulatory cells. Fish were, however, largely sensitive to infection, and less than 25% survived after 96 hpi. These surviving fish showed no evidence of stress (cortisol levels) or significant difference in microbiome diversity compared with controls at the same sampling time. The presence of T. maritimum in resistant fish skin and the total absence of any skin lesions suggest that these fish did not escape contact with the pathogen, but rather that some mechanisms prevented pathogens entry. In resistant individuals, we detected up-regulation of specific immune-related genes differentiating resistant individuals from controls at 96 hpi, which suggests a possible genomic basis of resistance, although no genetic variation in coding regions was found. Conclusion Here we focus in detail on the interplay between common fish pathogens and host immune response during experimental infection. We further highlight key actors of defence response, pathogenicity and possible genomic bases of fish resistance to T. maritimum.

Objective: To investigate and describe the variation in enamel daily secretion rates (DSRs) of naturally exfoliated deciduous molars (n = 345) from five modern-day populations (Aotearoa New Zealand, Britain, Canada, France, and Sweden). \ud \ud Design: Each tooth was thin sectioned and examined using a high-powered Olympus BX51 microscope and DP25 digital microscope camera. Mean DSRs were recorded for the inner, mid, and outer regions of cuspal and lateral enamel, excluding enamel nearest the enamel-dentin junction and at the outermost crown surface.\ud \ud Results: Mean DSRs did not vary significantly between populations, or by sex. Cuspal enamel grew slightly faster than lateral enamel (mean difference 0.16 µm per day; p < 0.001). The trajectory of DSRs remained relatively constant from inner to outer cuspal enamel and increased slightly in lateral enamel (p = 0.003). \ud \ud Conclusions: The DSRs of deciduous molars from modern-day children are remarkably consistent when compared among populations. While growth rates are faster in cuspal than lateral enamel, the trajectory of enamel formation changes only slightly from inner to outer regions. The trajectory of DSRs for deciduous molars differs to that of permanent molar enamel, which typically display a steep increase in matrix deposition from inner to outer enamel.

International audience; The anionic alternating ring-opening copolymerizations of three bio-based aromatic monomers, eugenol glycidyl ether (EGE), dihydroeugenol glycidyl ether (DEGE) and vanilin glycidyl ether (VGE), were carried out with renewable N-acetyl homocysteine thiolactone (NHTL) using benzyl alcohol and 2-tert-butylimino-2-diethylamino-1,3-dimethylperhydro-1,3,2-diazaphosphorine (BEMP) as initiating system. This polymerization is a rare example of eugenol-based monomers used to synthesize linear polyesters. Alternating poly(ester-alt-thioether)s are obtained with number-average molar masses M n ranging from 1.1 to 10.8 kg mol-1 and dispersities as low as 1.20. The copolymer structures were carefully characterized by 1 H, 13 C, COSY, HSQC, 1 H-15 N NMR. It was found that the alternate copolymers were obtained selectively under different monomer feed ratios. In addition, the use of EGE and VGE monomers allows the preparation of multi-functional poly(ester-alt-thioether) respectively bearing allyl or aldehyde groups in each repeating unit. The copolymers display only clear glass transition temperatures higher than ambient temperature. This alternating copolymerization method offers a new chemical pathway for the valorization of bio-based aromatic compounds and expand the scope of renewable polyesters.