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International audience; Over the last 40 years, research on (sub)fossil Spanish ibex (Capra pyrenaica) in the French Pyrenees is mainly based on discoveries made by cavers. In the western Pyrenees, more than 25 natural sites yielding Spanish ibex remains are known allowing palaeoecological research. Based on topographical settings (maps, bone location), paleontological records (osteometry, sexual dimorphism) and taphonomic analysis (skeletal discarding, biotic/abiotic traces), this paper provides information on the formation processes for some unpublished caprid sites. The deposits are mainly located in high mountains, in (deep) vertical holes or descending galleries having trapped one or two adult Spanish ibex or exceptionally several (non-) adult individuals. Osteometrical dataset suggests that males are more often trapped than females. Bone surfaces do not bear any important predator nor scavenger activities (large and/or small carnivores). The sites correspond to natural incursions of Spanish ibex into dark galleries, which are diachronic and/or independent of wintering occupations by brown bears (Ursus arctos). Résumé L'histoire récente du bouquetin d'Espagne (Capra pyrenaica) dans les Pyrénées françaises : une contribution de la spéléologie à la paléontologie. Au cours des 40 dernières années, les recherches sur les bouquetins des Pyrénées (Capra pyrenaica) reposent principalement sur des découvertes spéléologiques. Dans les Pyrénées occidentales, plus de 25 sites naturels renfermant des restes de bouquetins sont actuellement connus, autorisant des recherches paléoécologiques. A partir des données topographiques, paléontologiques et taphonomiques, cet article propose de caractériser les processus de formation des sites à caprinés. Les ossements sont principalement situés en haute montagne, au fond de puits (profonds), ou dans des grottes à galeries descendantes (ressauts), ayant piégé un à deux individus et exceptionnellement plusieurs animaux (non-) adultes. Les données ostéologiques (mesures) suggèrent que les bouquetins mâles sont plus fréquemment piégés que les femelles. Les surfaces osseuses ne présentent pas d'importantes traces de prédation ou de charognage (grands/petits carnivores). Ces sites correspondent à des incursions naturelles de bouquetins dans les galeries sombres qui sont indépendantes/diachroniques des occupations hivernales par les ours bruns (Ursus arctos).; L'histoire récente du bouquetin d'Espagne (Capra pyrenaica) dans les Pyrénées françaises : une contribution de la spéléologie à la paléontologie. Au cours des 40 dernières années, les recherches sur les bouquetins des Pyrénées (Capra pyrenaica) reposent principalement sur des découvertes spéléologiques. Dans les Pyrénées occidentales, plus de 25 sites naturels renfermant des restes de bouquetins sont actuellement connus, autorisant des recherches paléoécologiques. A partir des données topographiques, paléontologiques et taphonomiques, cet article propose de caractériser les processus de formation des sites à caprinés. Les ossements sont principalement situés en haute montagne, au fond de puits (profonds), ou dans des grottes à galeries descendantes (ressauts), ayant piégé un à deux individus et exceptionnellement plusieurs animaux (non‐) adultes. Les données ostéologiques (mesures) suggèrent que les bouquetins mâles sont plus fréquemment piégés que les femelles. Les surfaces osseuses ne présentent pas d’importantes traces de prédation ou de charognage (grands/petits carnivores). Ces sites correspondent à des incursions naturelles de bouquetins dans les galeries sombres qui sont indépendantes/diachroniques des occupations hivernales par les ours bruns (Ursus arctos).

The large bovids, bison and aurochs, both feature in Paleolithic archaeofauna and art, particularly in Southwestern Eu- rope during the Late Upper Pleistocene. We present a brief taxonomic and morphological description of the bovid spe- cies present at that time, as well as their biogeographical distribution. We then compare this distribution data with their presence in cave and portable art from this period and describe and interpret their depictions according to a number of themes. Our knowledge of the anatomical traits and ecology of these species allows us to better identify and interpret their representation in cave art and portable art made by hunter-gatherer societies. Several examples of Paleolithic art are given, illustrating the relationship between biological context and socio-economic value, and allowing us to under- stand the particular and highly symbolic nature of the relationship between humans and bovids. Beyond subsistence, Paleolithic representations clearly demonstrate a mythological dimension.

Les lynx sont rares dans le registre paleontologique quaternaire. Fouillee dans les annees 1960 par Eugene et Marie-Francoise Bonifay, la grotte de l’Escale, dans le Sud-Est de la France (Bouches-du-Rhone), renferme un puissant remplissage, date de la premiere moitie du Pleistocene moyen. La presente etude dresse un inventaire actualise des restes crâniens et postcrâniens de lynx identifies dans les differents niveaux et livre un corpus osteometrique pour l’ensemble des elements squelettiques. Le nombre de restes attribues a cette espece est de 435, le nombre minimal d’individus de 15, faisant de la grotte de l’Escale l’un des plus riches gisements a lynx des cavernes d’Europe. Par ses caracteristiques morphologiques dentaires, ce lynx appartient au lynx pardelle, dont il constitue une sous-espece evolutive en raison de la frequence elevee du metaconide sur la carnassiere inferieure. Les donnees osteometriques pour chaque dent / os, mises en ligne sur internet, permettent de decrire une « population » de lynx homogene avec un faible dimorphisme sexuel. Des donnees taphonomiques (fragmentation osseuse in situ, quasi absence de traces de predation) et paleobiologiques (population composee d’individus adultes) suggerent un piegeage des lynx dans les remplissages verticaux (dolines, cheminees) du site.

National audience; Connue pour être un site archéologique exceptionnel par ses figurations pariétales datées du tout début du Paléolithique supérieur, la grotte Chauvet est aussi un site paléontologique majeur. Elle conserve notamment les restes osseux et les empreintes de deux grands Canidés : le loup et le dhole. Les études paléontologiques et ichnologiques entreprises ces dernières années permettent de mieux connaître les comportements préhistoriques de ces deux espèces, sans équivalents actuels. L’association d’empreintes de loup et d’Homme anatomiquement moderne dans certains secteurs de la grotte vient aussi questionner les possibles relations qu’entretenaient ces deux prédateurs.

Célèbre depuis le début du XXe siècle par ses gravures, la grotte des Combarelles (Les Eyzies, Dordogne, France), a livré depuis une quarantaine d’années quelques échantillons paléontologiques lors d’interventions archéologiques ou spéléologiques ponctuelles. Parmi les collections du Musée national de Préhistoire, une portion diaphysaire d’un os long de taille importante est rapportée à un tibia non épiphysé de mammouth laineux (Mammuthus primigenius Blumenbach, 1798). En dépit de toute précision contextuelle (topographie, chrono-culture), cet os présente le double intérêt de porter des traces de découpe sur sa face caudale d’une part et d’avoir pu être directement daté d’autre part. Les deux dates radiocarbone AMS obtenues sur un fragment cortical prélevé sur ce tibia sont respectivement de 14 310 ± 70 et de 14 620 ± 100 uncal BP, soit ~ 17 500 cal BP ou ~ 15 600 cal BC. Il s’agit de la première date AMS sur os de mammouth laineux pour le Sud-Ouest de la France. Une révision de la présence de l’espèce dans les registres paléontologiques, symboliques (art pariétal et art mobilier) et économiques (industrie en ivoire) est engagée et suggère que le mammouth laineux a perduré jusqu’au début du Magdalénien supérieur dans la grande plaine d’Aquitaine et les régions limitrophes. Famous since the beginning of the XXth century for its engravings, the Combarelles cave has produced bone fragments over the last 40 years during sporadic fieldwork research in Archaeology and Speleology. Among provided samples held in the National Museum of Prehistory, a shaft of a large long bone was found and identified as an unfused tibia belonging to the woolly mammoth (Mammuthus primigenius Blumenbach, 1798). Although precise information of this discovery is still unknown (location, topographical context), this bone is important because of some cutmarks visible on its posterior side and direct radiocarbon dating. Two dates (14310 ± 70 and 14620 ± 100 uncal BP respectively, i.e. ~ 17 500 cal BP or ~ 15 600 cal BC) were obtained and are the first AMS radiocarbon dates for this species in Southwestern France. A revision of this species in the paleontological, symbolic (rock art and portable art) and economic (ivory) records is presented and suggests that the woolly mammoth had survived until the beginning of the Late Magdalenian in Aquitaine and in adjacent regions.

An infectious retroviral particle contains 1000–1500 molecules of the nucleocapsid protein (NC) that cover the diploid RNA genome. NC is a small zinc finger protein that possesses nucleic acid chaperone activity that enables NC to rearrange DNA and RNA molecules into the most thermodynamically stable structures usually those containing the maximum number of base pairs. Thanks to the chaperone activity, NC plays an essential role in reverse transcription of the retroviral genome by facilitating the strand transfer reactions of this process. In addition, these reactions are involved in recombination events that can generate multiple drug resistance mutations in the presence of anti-HIV-1 drugs. The strand transfer reactions rely on base pairing of folded DNA/RNA structures. The molecular mechanisms responsible for NC-mediated strand transfer reactions are presented and discussed in this review. Antiretroviral strategies targeting the NC-mediated strand transfer events are also discussed., Highlights • DNA strand transfers are essential steps of reverse transcription in retroviruses. • DNA strand transfers rely on base pairing of structured nucleic acids. • In vitro studies identified NC as an actor who facilitates DNA strand transfers. • NC increases the rate of transfers, thanks to its nucleic acid chaperone activity. • The nucleic acid-NC complexes are potential targets for antiretroviral therapy.

International audience

International audience

International audience

International audience; This first volume of Monographie de la grotte Chauvet-Pont d’Arc presents a reasoned inventory of the information contained in the cave in the form of an atlas. While this type of publication may seem unusual, the dimensions of the cave, the morphology of the chambers and galleries that compart-mentalize its space, as well as the inscription of artworks in its underground landscape, are all invitations to reflect upon, study and structure our knowledge of the cave using a cartographic approach. The progressive presentation of the Atlas de la grotte Chauvet-Pont d’Arc enables us to address, in the most neutral manner possible, the complexity and factual richness, often emphasized, of this underground sanctuary.The proposed itinerary, close to that of the current path of the walkways from the entrance to the end of the cavity, invites us to discover the cave via twenty maps extracted from the integrated map of the cave floors. Moving through the cave and into its smallest and most intimate spaces, each person can shape their reading according to their interests. The visit to each of the twenty zones is organized according to the same narrative structure. The first page, accompa-nied by a panoramic photograph, presents the main charac-teristics of the zone and the themes that will be addressed. Depending on the sectors, the archaeology, paleontology, geology, speleogenesis or underground landscape is empha-sized. The second and third pages are positioned opposite each other and are designed to interact. The second page presents the integrated map reproduced at the 1:100 scale. Below it, a thumbnail representation enables the reader to identify the location of the map within the cave. A small map at the 1:300 scale presents the cave floor in 3D and shows the location, feature and artwork designations, the permanent and temporary paths installed for observations, as well as the camera angles and the position of the longitudinal profile of the zone. A synoptic figure shows the relative representation of each of the research domains in the map zone. The pages that follow provide an initial synthesis of the observations and research in progress. These aspects will be presented in detail in the succeeding volumes of the Atlas de la grotte Chauvet-Pont d’Arc.

International audience

International audience

International audience

Carte intégrée des sols, Carte 18 Integrated map of the floors, Map 18 Emplacement de la Carte 18 au sein de la grotte Location of Map 18 in the cave Importance des objets d’étude en Carte 18 Relative proportions of observed objects on Map 18 Désignations et angles de prise de vue Designations and camera angles Coupe transversale AA’ Cross section AA’ On accède à la Galerie des Mégacéros depuis la Salle Hillaire, qui s’ouvre en léger surplomb à droite de l’Alcôve du Rhinocéros [fig. 228]...

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International audience

International audience; 2. « Une guilde est un groupe d'espèces utilisant la même ressource et dont les niches se chevauchent en partie. Par extension, l'ensemble des carnivores sera considéré comme une guilde, bien que composée d'espèces diurnes ou nocturnes, omnivores ou hypercarnivores, n'entrant pas toujours en compétition » (Brugal, Fosse, 2004 : 581). Résumé.-Deux sites monégasques en grottes livrent des ensembles fossiles très diversifiés en carnivores. La comparaison des associations précisent à la fois la biochronologie des dépôts mais aussi la taphonomie de ces ensembles et les environnements pléistocènes contemporains. Pleistocene Carnivores from Monaco Principaty. The caves of Observatoire and Saint-Martin Keywords.-Carnivores, Pleistocene, Monaco, Cave sites. Abstract.-Two Monegasque sites in caves yield very diversified fossil carnivore species. The comparison of associations specifies both the biochronology of the deposits but also the taphonomy of these sets as well as contemporary Pleistocene environments.

International audience

International audience; This first volume of Monographie de la grotte Chauvet-Pont d’Arc presents a reasoned inventory of the information contained in the cave in the form of an atlas. While this type of publication may seem unusual, the dimensions of the cave, the morphology of the chambers and galleries that compart-mentalize its space, as well as the inscription of artworks in its underground landscape, are all invitations to reflect upon, study and structure our knowledge of the cave using a cartographic approach. The progressive presentation of the Atlas de la grotte Chauvet-Pont d’Arc enables us to address, in the most neutral manner possible, the complexity and factual richness, often emphasized, of this underground sanctuary.The proposed itinerary, close to that of the current path of the walkways from the entrance to the end of the cavity, invites us to discover the cave via twenty maps extracted from the integrated map of the cave floors. Moving through the cave and into its smallest and most intimate spaces, each person can shape their reading according to their interests. The visit to each of the twenty zones is organized according to the same narrative structure. The first page, accompa-nied by a panoramic photograph, presents the main charac-teristics of the zone and the themes that will be addressed. Depending on the sectors, the archaeology, paleontology, geology, speleogenesis or underground landscape is empha-sized. The second and third pages are positioned opposite each other and are designed to interact. The second page presents the integrated map reproduced at the 1:100 scale. Below it, a thumbnail representation enables the reader to identify the location of the map within the cave. A small map at the 1:300 scale presents the cave floor in 3D and shows the location, feature and artwork designations, the permanent and temporary paths installed for observations, as well as the camera angles and the position of the longitudinal profile of the zone. A synoptic figure shows the relative representation of each of the research domains in the map zone. The pages that follow provide an initial synthesis of the observations and research in progress. These aspects will be presented in detail in the succeeding volumes of the Atlas de la grotte Chauvet-Pont d’Arc.

International audience; Un lion des cavernes (Panthera (Leo) spelaea) exploité au Dryas récent : les données du gisement du Peyrat (Saint-Rabier, Dordogne, France) Philippe FOSSE (a) , Stéphane MADELAINE (b) , Christine OBERLIN (c) , Catherine CRETIN (b) , Peggy BONNET-JACQUEMENT (b) Résumé : Dans les années 1960, les fouilles du gisement du Peyrat (Saint-Rabier, Dordogne) par A. Cheynier ont livré un abondant matériel lithique et osseux, rapporté au Magdalénien et à l'Azilien. La stratigraphie complexe, décrite à partir de cinq tranchées profondes, comprend une dizaine de couches d'inégale puissance dans lesquelles de très nombreux vestiges paléontologiques ont été recueillis. Ponctuellement déterminée (carnets de terrain de Cheynier) à partir de restes dentaires, la faune se compose principalement du renne et du cerf. La révision de quelques pièces paléontologiques déterminables a permis à l'un des auteurs (SM) d'identifier la présence du lion des cavernes à partir d'une colonne vertébrale sub-complète (sept vertèbres cervicales, six vertèbres thoraciques, six vertèbres lombaires), rapportée à un individu mâle. La présence de ce Félidé dans un contexte stratigraphique de l'extrême fin du Tardiglaciaire, dans un horizon culturel azilien récent, est étayée par une date radiométrique directe de 10590 ± 70 BP (SacA-38311), soit-10755/-10455 cal BC (2 ). Cette date est, à ce jour, la plus récente jamais obtenue pour cette espèce à l'échelle eurasiatique. De plus, deux vertèbres (atlas, 12 e vertèbre thoracique) présentent des traces de découpe. Le présent article dresse un bilan géo-chronologique des restes du lion des cavernes dans le Sud-Ouest de la France (nord Aquitaine-versant sud des Pyrénées) et souligne l'intérêt des gisements régionaux dans les études taphonomiques et zooarchéologiques concernant la disparition de la grande faune glaciaire.

International audience; SHAPE chemistry (selective 2’-hydroxyl acylation analyzed by primer extension) has been developed to specifically target flexible nucleotides (often unpaired nucleotides) independently to their purine or pyrimidine nature for RNA secondary structure determination. However, to the best of our knowledge, the structure of 2’-O-acylation products has never been confirmed by NMR or X-ray data. We have realized the acylation reactions between cNMP and NMIA under SHAPE chemistry conditions and identified the acylation products using standard NMR spectroscopy and LC-MS/MS experiments. For cAMP and cGMP, the major acylation product is the 2’-O-acylated compound (> 99 %). A trace amount of N-acylated cAMP has also been identified by LC-UV-MS². While for cCMP, the isolated acylation products are composed of 96 % of 2’-O-acylated, 4 % of N,O-diacylated, and trace amount of N-acylated compounds. In addition, the characterization of the major 2’-O-acylated compound by NMR showed slight differences in the conformation of the acylated sugar between the three cyclic nucleotides. This interesting result should be useful to explain some unexpected reactivity of the SHAPE chemistry.

International audience

International audience; This contribution presents a general account and summary of the research carried out over the past decades on the Quaternary faunas of France. This country is located in the center of Western Europe, and presents distinct topographical features and very varied climatic influences. This paper is the result of collaborative work between French teams and different researchers specialized in the paleontology of large mammals. Over a hundred paleontological or archaeological sites are mentioned in this review, which covers a broad chronological period, ranging from the Early (including the end of Pliocene/Gelasien) and Middle Pleistocene to the Late Pleistocene. One of the aims of this work is to present studies of the main families or subfamilies of herbivores (Equidae, Rhinocerotidae, Bovidae [Bovines, Caprines, Antilopines, and Rupicaprines], Cervidae, Proboscid) and carnivores (Canidae, Ursidae, Mustelidae, Hyenidae, Felidae). It is not exhaustive at the generic and specific level, but details on the taxonomic status, evolutionary levels and biochronological importance of the most important taxa are given alongside an extensive and up-to-date bibliography of French works.; Cette contribution expose un bilan général et synthétique des recherches menées ces dernières décades en France sur les faunes Quaternaires de ce pays situé au centre de l’Europe de l’Ouest, avec une topographie et des influences climatiques très variées. Cet article est le résultat d’un travail collectif entre différents spécialistes et équipes françaises en Paléontologie des grands mammifères. Près d’une centaine de gisements, paléontologiques ou archéologiques sont concernés et couvrent une large période, depuis la fin du Pliocène, le Pléistocène inférieur et moyen jusqu’au Pléistocène supérieur. Un des buts du travail est de présenter les études réalisées sur les principales familles ou sous-familles d’herbivores (Équidés, Rhinocérotidés Bovidés [Bovinés, Caprinés, Antilopinés, Rupicaprinés] Cervidés, Proboscidiens) et de carnivores (Canidés, Ursidés, Mustélidés, Hyénidés, Félidés). Sans être exhaustif au niveau générique et spécifique, des précisions sur le statut taxonomique, les degrés évolutifs et l’importance biochronologique des taxons sont présentées, accompagnées d’une bibliographie abondante et à jour des travaux français.

International audience; En raison de l'exceptionnel état de conservation des parois (peintures ...) et des sols (ossements, empreintes, coprolithes), la grotte Chauvet Pont d'Arc est un site remarquable, qui permet de relever et de s'interroger sur les fréquentations humaines et animales au cours du Paléolithique supérieur ancien (~45.000 - 28.000 ans cal BP).Parmi les témoignages originaux contenus dans la plupart des galeries de la cavité, depuis l'entrée paléolithique jusqu'aux parois ornées, figurent des restes osseux et plusieurs plages argileuses marquées d'empreintes attribués à de grands Canidés. La présence d'un Canidé "apprivoisé" avait été suggérée par M. A. Garcia à partir de ses relevés ichnologiques.Les conditions particulières d'étude (observations à distance, accessibilité des galeries, non manipulation des ossements, enfouissement partiel des vestiges et des traces) nécessitent une méthode d'étude adaptée afin de restituer au plus juste ces données paléobiologiques. Pour la première fois, un travail combinant données paléontologiques et ichnologiques est proposé pour des Canidés pléistocènes en contexte karstique (relevés et code de mesurages des empreintes, diagnose ichnologique). A partir de relevés photogrammétriques et des modélisations 3D des ossements suffisamment visibles (n=10) et des empreintes sub-complètes (n=17), une étude comparative reposant sur l'ostéométrie et la morphologie des restes osseux et empreintes de grands Canidés eurasiatiques modernes et fossiles, suggère la présence de deux taxons, le loup (Canis lupus) et le cuon (Cuon alpinus). Une discussion sur des considérations paléoéthologiques (occupation naturelle des cavités profondes, association avec les secteurs anthropisés (Art, empreintes humaines) est enfin abordée.

Due to its essential roles in the viral replication cycle and to its highly conserved sequence, the nucleocapsid protein (NCp7) of the human immunodeficiency virus type 1 is a target of choice for inhibiting replication of the virus. Most NCp7 inhibitors identified so far are small molecules. A small number of short peptides also act as NCp7 inhibitors by competing with its nucleic acid (NA) binding and chaperone activities but exhibit antiviral activity only at relatively high concentrations. In this work, in order to obtain more potent NCp7 competitors, we designed a library of longer peptides (10-17 amino acids) whose sequences include most of the NCp7 structural determinants responsible for its specific NA binding and destabilizing activities. Using an in vitro assay, the most active peptide (pE) was found to inhibit the NCp7 destabilizing activity, with a 50% inhibitory concentration in the nanomolar range, by competing with NCp7 for binding to its NA substrates. Formulated with a cell-penetrating peptide (CPP), pE was found to accumulate into HeLa cells, with low cytotoxicity. However, either formulated with a CPP or overexpressed in cells, pE did not show any antiviral activity. In vitro competition experiments revealed that its poor antiviral activity may be partly due to its sequestration by cellular RNAs. The selected peptide pE therefore appears to be a useful tool for investigating NCp7 properties and functions in vitro, but further work will be needed to design pE-derived peptides with antiviral activity.

International audience

Recently, a 3-hydroxychromone based nucleoside 3HCnt has been developed as a highly environment-sensitive nucleoside surrogate to investigate protein-DNA interactions. When it is incorporated in DNA, the probe is up to 50-fold brighter than 2-aminopurine, the reference fluorescent nucleoside. Although the insertion of 3HCnt in DNA was previously shown to not alter the overall DNA structure, the possibility of the probe inducing local effects cannot be ruled out. Hence, a systematic structural and dynamic study is required to unveil the 3HCnt's limitations and to properly interpret the data obtained with this universal probe. Here, we investigated by NMR a 12-mer duplex, in which a central adenine was replaced by 3HCnt. The chemical shifts variations and nOe contacts revealed that the 3HCnt is well inserted in the DNA double helix with extensive stacking interactions with the neighbor base pairs. These observations are in excellent agreement with the steady-state and time-resolved fluorescence properties indicating that the 3HCnt fluorophore is protected from the solvent and does not exhibit rotational motion. The 3HCnt insertion in DNA is accompanied by the extrusion of the opposite nucleobase from the double helix. Molecular dynamics simulations using NMR-restraints demonstrated that 3HCnt fluorophore exhibits only translational dynamics. Taken together, our data showed an excellent intercalation of 3HCnt in the DNA double helix, which is accompanied by localized perturbations. This confirms 3HCnt as a highly promising tool for nucleic acid labeling and sensing.

As chemical methods for RNA secondary structure determination, SHAPE chemistry (selective 2′-hydroxyl acylation analyzed by primer extension) has been developed to specifically target flexible nucleotides (often unpaired nucleotides) independently to their purine or pyrimidine nature. In order to improve the specificity of acylating reagents towards unpaired nucleotides, we have explored the reactivity of symmetric anhydrides, acyl fluorides, active esters like succinimidyl ester and cyanomethyl esters for 2′- O -acylation reaction. Among the tested compounds, only the acyl fluoride 4 showed a low reactivity (compared to NMIA). However, this study is the first to show that nucleophilic catalysts like DMAP greatly improved the selective 2′-hydroxyl acylation by symmetric anhydrides, acyl fluorides and succinimidyl ester, with the 2-fluorobenzoic anhydride 5 being the most reactive.

Le gisement paléontologique de Fouvent (Fouvent-le-Bas, Haute-Saône, France) est une accumulation osseuse karstique connue depuis le début du XIXe siècle. Ce site est à l’origine de nombreuses avancées paléontologiques (reconnaissance de l’hyène fossile par Cuvier, première mention du glouton en France) et taphonomique (caractérisation du repaire de carnivore). Le présent article porte sur l’analyse de 14 977 restes osseux issus à la fois de la collection historique (fouilles de 1842) et des fouilles récentes (1989-1992). Une liste faunique de 19 taxons de grands mammifères a été établie : 11 carnivores (Crocuta crocuta spelaea, Panthera (Leo) spelaea, Ursus spelaeus, Canis lupus, Vulpes vulpes, cf. Alopex, Gulo gulo, Meles meles, Martes sp., Mustela eversmanii, Mustela sp.) et 8 ongulés (Mammuthus primigenius, Coelodonta antiquitatis, Megaloceros giganteus, Cervus elaphus, Rangifer tarandus, Equus germanicus, Bos primigenius et/ou Bison priscus). L’étude des hyènes des cavernes permet de préciser les caractères d’une population du stade isotopique 3 et de discuter de sa composition. Quant au spectre d’ongulés, son identification permet de préciser la diversité des proies de l’hyène (en termes d’espèces et d’âges individuels). Les interactions entre le prédateur et ses proies sont caractérisées grâce à l’étude de la distribution squelettique, de la fragmentation osseuse, des morphologies des restes consommés et des traces de dents. L’examen détaillé de l’ensemble des éléments taphonomiques de l’accumulation osseuse de Fouvent permet de discuter et de préciser la spécificité d’un repaire d’hyènes pléistocène. The palaeontological site of Fouvent (Fouvent-le-Bas, Haute-Saône, France) is a fissure-filling bone accumulation known from the beginning of the XIXth century. This assemblage is at the origin of palaeontological (description of fossil hyena by Cuvier, first record of French wolverine) and taphonomical advances (first carnivore den characterization). This paper presents the analysis of 14 977 bone remains from both the historical collection (1842) and recent excavations (between 1989 and 1992). A faunal list of 19 mammalian species has been identified: 11 carnivore species (Crocuta crocuta spelaea, Panthera (Leo) spelaea, Ursus spelaeus, Canis lupus, Vulpes vulpes, cf. Alopex, Gulo gulo, Meles meles, Martes sp., Mustela eversmanii, Mustela sp.) and 8 large ungulate species (Mammuthus primigenius, Coelodonta antiquitatis, Megaloceros giganteus, Cervus elaphus, Rangifer tarandus, Equus germanicus, Bos primigenius and/or Bison priscus). The analysis of cave hyenas from Fouvent allows us to precise characteristics of an OIS3 population and to discuss population structure. The study of ungulate populations allows us to describe prey diversity (in terms of species and individual age). Prey skeletal part distribution, bone fragmentation, consumption morphotypes and tooth marks are observed to point out predator-prey interactions. The detailed analysis of taphonomical aspects of Fouvent bone accumulation allows also to discuss and to give criteria about hyena den characterization grids.

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If cave bear (Ursus spelaeus) sites are suspected to be occupied during winters (hibernation), studies clearly demonstrating seasons of cave occupation by this species are still rare, and are mainly based on cementochronology. However, in numerous cave bear sites, postcranial elements belonging to non-adult individuals at different ontogenic stages are abundant and better preserved than are teeth. Studies on brown bear (Ursus arctos) skeletal growth have considered sequences of eruption and wear of deciduous teeth, and sometimes length of skulls or long bone epiphysation. In order to appraise seasons of cave occupation by Ursids, measurements have been taken on modern and subfossil complete brown bear skeletons. Those samples concern measurements taken from pictures (one 6-day old in Natural History Museum in Vienna (Austria), one 10-day old individual) or directly taken by the present authors (2 skeletons of Pyrenean modern 6-month old individuals in Natural History museum, Toulouse; an articulated skeleton belonging to the same stage of growth coming from the Mont Ventoux natural trap n°29 (MV29); and an articulated Pyrenean juvenile skeleton coming from the Trou Sylvain natural trap). Individual ages of those skeletons have been determined with eruption sequence of deciduous teeth and concern the first 2 years of brown bear life. Measurements on those samples have been taken and have been compared to the huge Holocene samples from 2 Mont Ventoux (MV2, MV4) natural traps, yielding each several hundred non-adult postcranial elements. As far as is known, those sites yield the largest brown bear populations from Europe. Seasonality has been previously studied from deciduous teeth eruption sequences. For postcranial elements, found discarded or mixed together, no analysis has been achieved. The goals of the current work are: 1) to match estimation of age from postcranial elements with the teeth eruption sequences; 2) to present rates of growth from appendicular elements during the first 2 years of life; 3) to evaluate evidence of sexual dimorphism during early life; and 4) to compare growth of brown bear postcranial skeleton with cave bear homologues. This work might provide interesting information on chronology of osseous growth and on seasons of cave occupations (winter vs annual occupation).

The HIV-1 transactivator of transcription (Tat) protein is thought to stimulate reverse transcription (RTion). The Tat protein and, more specifically, its (44–61) domain were recently shown to promote the annealing of complementary DNA sequences representing the HIV-1 transactivation response element TAR, named dTAR and cTAR, that plays a key role in RTion. Moreover, the kinetic mechanism of the basic Tat(44–61) peptide in this annealing further revealed that this peptide constitutes a representative nucleic acid annealer. To further understand the structure–activity relationships of this highly conserved domain, we investigated by electrophoresis and fluorescence approaches the binding and annealing properties of various Tat(44–61) mutants. Our data showed that the Tyr47 and basic residues of the Tat(44–61) domain were instrumental for binding to cTAR through stacking and electrostatic interactions, respectively, and promoting its annealing with dTAR. Furthermore, the annealing efficiency of the mutants clearly correlates with their ability to rapidly associate and dissociate the complementary oligonucleotides and to promote RTion. Thus, transient and dynamic nucleic acid interactions likely constitute a key mechanistic component of annealers and the role of Tat in the late steps of RTion. Finally, our data suggest that Lys50 and Lys51 acetylation regulates Tat activity in RTion.

The mature HIV-1 nucleocapsid protein NCp7 (NC) plays a key role in reverse transcription facilitating the two obligatory strand transfers. Several properties contribute to its efficient chaperon activity: preferential binding to single-stranded regions, nucleic acid aggregation, helix destabilization, and rapid dissociation from nucleic acids. However, little is known about the relationships between these different properties, which are complicated by the ability of the protein to recognize particular HIV-1 stem–loops, such as SL1, SL2, and SL3, with high affinity and without destabilizing them. These latter properties are important in the context of genome packaging, during which NC is part of the Gag precursor. We used NMR to investigate destabilization of the full-length TAR (trans activating response element) RNA by NC, which is involved in the first strand transfer step of reverse transcription. NC was used at a low protein:nucleotide (nt) ratio of 1:59 in these experiments. NMR data for the imino protons of TAR identified most of the base pairs destabilized by NC. These base pairs were adjacent to the loops in the upper part of the TAR hairpin rather than randomly distributed. Gel retardation assays showed that conversion from the initial TAR–cTAR complex to the fully annealed form occurred much more slowly at the 1:59 ratio than at the higher ratios classically used. Nevertheless, NC significantly accelerated the formation of the initial complex at a ratio of 1:59.