Consulta: creatorFacets:"Auguet, Jean-christophe"
Registros recuperados: 15
Data/hora: 09/06/2024 02:29:14

Les virus de l'estuaire de la Charente el du bassin de Marennes-Oleron. Dynamiques spatio-temporelles et  interactions avec les communautés bactériennes
Provedor de dados: 5
Autores: Auguet, Jean-christophe.
This study is divided in two parts; one aim is to evaluate the in situ spalio-temporal dynamics of viral communities  in the Charante estuary in order to define the appropriate seasons to conduct in vitro viral enrichment experiments. These experiments, that constitute the second part of this study, were performed to assess the impact of freshwater viruses carried by the Charante River on the dynamics and composition of coastal bacterial communities. With abundance ranging from 1.4 x 107 to 208 x I07 VLPml-1. viruses are the most abundant component among plankton microorganisms in surface waters of the Charente estuary. Thre temporal dynamics of this component reflects the indirect influence of temperature through the control of bacterial abundance,...
Tipo: Text
Palavras-chave: Richesse spécifique; Composition clonale; Enrichissement vital; Infection lyrique; Structure des communautés; MET; PPGE; Dynamique temporelle; Gradient de salinité; Estuaire; Bactérioplancton; Virioplancton; Species richness; Clonal composition; Viral enrichment; Lytic infection; Community structure; Diversity; TEM; PEGE; Temporal dynamic; Gradient; Salinity; Estuary; Bacterioplankton; Virioplankton.
Ano: 2005
URL: http://archimer.ifremer.fr/doc/2005/these-3071.pdf

Seasonality of archaeal proteorhodopsin and associated Marine Group IIb ecotypes (Ca. Poseidoniales) in the North Western Mediterranean Sea
Provedor de dados: 5
Autores: Pereira, Olivier; Hochart, Corentin; Boeuf, Dominique; Auguet, Jean-christophe; Debroas, Didier; Galand, Pierre E.
The Archaea Marine Group II (MGII) is widespread in the world’s ocean where it plays an important role in the carbon cycle. Despite recent discoveries on the group’s metabolisms, the ecology of this newly proposed order (Candidatus Poseidoniales) remains poorly understood. Here we used a combination of time-series metagenome-assembled genomes (MAGs) and high-frequency 16S rRNA data from the NW Mediterranean Sea to test if the taxonomic diversity within the MGIIb family (Candidatus Thalassarchaeaceae) reflects the presence of different ecotypes. The MAGs’ seasonality revealed a MGIIb family composed of different subclades that have distinct lifestyles and physiologies. The vitamin metabolisms were notably different between ecotypes with, in some, a possible...
Tipo: Text
Ano: 2021
URL: https://archimer.ifremer.fr/doc/00663/77526/79334.pdf

Chronic Polyaromatic Hydrocarbon (PAH) Contamination Is a Marginal Driver for Community Diversity and Prokaryotic Predicted Functioning in Coastal Sediments
Provedor de dados: 5
Autores: Jeanbille, Mathilde; Gury, Jérôme; Duran, Robert; Tronczynski, Jacek; Ghiglione, Jean-françois; Agogué, Hélène; Saïd, Olfa Ben; Taïb, Najwa; Debroas, Didier; Garnier, Cédric; Auguet, Jean-christophe.
Benthic microorganisms are key players in the recycling of organic matter and recalcitrant compounds such as polyaromatic hydrocarbons (PAHs) in coastal sediments. Despite their ecological importance, the response of microbial communities to chronic PAH pollution, one of the major threats to coastal ecosystems, has received very little attention. In one of the largest surveys performed so far on coastal sediments, the diversity and composition of microbial communities inhabiting both chronically contaminated and non-contaminated coastal sediments were investigated using high-throughput sequencing on the 18S and 16S rRNA genes. Prokaryotic alpha-diversity showed significant association with salinity, temperature, and organic carbon content. The effect of...
Tipo: Text
Palavras-chave: Microbial communities; PAH; Chronic contamination; Coastal sediment; Functional diversity.
Ano: 2016
URL: http://archimer.ifremer.fr/doc/00347/45854/45522.pdf

Resistance of the oyster pathogen   Vibrio tasmaniensis   LGP32 against grazing by   Vannella sp   . marine amoeba involves Vsm and CopA virulence factors
Provedor de dados: 5
Autores: Robino, Etienne; Poirier, Aurore C.; Amraoui, Hajar; Le Bissonnais, Sandra; Perret, Angelique; Lopez‐joven, Carmen; Auguet, Jean-christophe; Rubio, Tristan P.; Cazevieille, Chantal; Rolland, Jean-luc; Héchard, Yann; Destoumieux‐garzón, Delphine; Charrière, Guillaume.
ibrios are ubiquitous in marine environments and opportunistically colonize a broad range of hosts. Strains of Vibrio tasmaniensis present in oyster farms can thrive in oysters during juvenile mortality events and behave as facultative intracellular pathogen of oyster hemocytes. Herein, we wondered whether V. tasmaniensis LGP32 resistance to phagocytosis is specific to oyster immune cells or contributes to resistance to other phagocytes, like marine amoebae. To address this question, we developed an integrative study, from the first description of amoeba diversity in oyster‐farms to the characterization of LGP32 interactions with amoebae. An isolate of the Vannella genus, Vannella sp. AP1411, which was collected from oyster farms, is ubiquitous, and...
Tipo: Text
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00509/62109/66292.pdf

Skin microbiome of coral reef fish is highly variable and driven by host phylogeny and diet
Provedor de dados: 5
Autores: Chiarello, Marlene; Auguet, Jean-christophe; Bettarel, Yvan; Bouvier, Corinne; Claverie, Thomas; Graham, Nicholas A. J.; Rieuvilleneuve, Fabien; Sucre, Elliot; Bouvier, Thierry; Villeger, Sebastien.
Background: The surface of marine animals is covered by abundant and diversified microbial communities, which have major roles for the health of their host While such microbiomes have been deeply examined in marine invertebrates such as corals and sponges, the microbiomes living on marine vertebrates have received less attention. Specifically, the diversity of these microbiomes, their variability among species, and their drivers are still mostly unknown, especially among the fish species living on coral reefs that contribute to key ecosystem services while they are increasingly affected by human activities. Here, we investigated these knowledge gaps analyzing the skin microbiome of 138 fish individuals belonging to 44 coral reef fish species living in the...
Tipo: Text
Palavras-chave: Tropical; Teleost; Microbiota; Phylogenetic diversity; Phylosymbiosis; Phylogenetic signal.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00454/56565/74934.pdf

Exceptional but vulnerable microbial diversity in coral reef animal surface microbiomes
Provedor de dados: 5
Autores: Chiarello, Marlène; Auguet, Jean-christophe; Graham, Nicholas A. J.; Claverie, Thomas; Sucré, Elliott; Bouvier, Corinne; Rieuvilleneuve, Fabien; Restrepo-ortiz, Claudia Ximena; Bettarel, Yvan; Villéger, Sébastien; Bouvier, Thierry.
Coral reefs host hundreds of thousands of animal species that are increasingly threatened by anthropogenic disturbances. These animals host microbial communities at their surface, playing crucial roles for their fitness. However, the diversity of such microbiomes is mostly described in a few coral species and still poorly defined in other invertebrates and vertebrates. Given the diversity of animal microbiomes, and the diversity of host species inhabiting coral reefs, the contribution of such microbiomes to the total microbial diversity of coral reefs could be important, yet potentially vulnerable to the loss of animal species. Analysis of the surface microbiome from 74 taxa, including teleost fishes, hard and soft corals, crustaceans, echinoderms,...
Tipo: Text
Palavras-chave: Skin microbiota; Phylogenetic diversity; Conservation; Marine biodiversity; Octocorallia; Scleratinia.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00629/74121/73596.pdf

Genomic ecology of Marine Group II, the most common marine planktonic Archaea across the surface ocean
Provedor de dados: 5
Autores: Pereira, Olivier; Hochart, Corentin; Auguet, Jean-christophe; Debroas, Didier; Galand, Pierre E.
Planktonic Archaea have been detected in all the world's oceans and are found from surface waters to the deep sea. The two most common Archaea phyla are Thaumarchaeota and Euryarchaeota. Euryarchaeota are generally more common in surface waters, but very little is known about their ecology and their potential metabolisms. In this study, we explore the genomic ecology of the Marine Group II (MGII), the main marine planktonic Euryarchaeota, and test if it is composed of different ecologically relevant units. We re‐analyzed Tara Oceans metagenomes from the photic layer and the deep ocean by annotating sequences against a custom MGII database and by mapping gene co‐occurrences. Our data provide a global view of the distribution of Euryarchaeota, and more...
Tipo: Text
Palavras-chave: 16S rRNA; Euryarchaeota; Global ocean; Metagenomics; Poseidoniales; Proteorhodopsin.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00505/61676/65607.pdf

A community perspective on the concept of marine holobionts: state-of-the-art, challenges, and future directions
Provedor de dados: 5
Autores: Dittami, Simon M; Arboleda, Enrique; Auguet, Jean-christophe; Bigalke, Arite; Briand, Enora; Cardenas, Paco; Cardini, Ulisse; Decelle, Johan; Engelen, Aschwin; Eveillard, Damien; Gachon, Claire Mm; Griffiths, Sarah; Harder, Tilmann; Kayal, Ehsan; Kazamia, Elena; Lallier, François H; Media, Monica; Marzinelli, Ezequiel M; Morganti, Teresa; Nunez Pons, Laura; Prado, Soizik; Pintado, José; Saha, Mahasweta; Selosse, Marc-andré; Skillings, Derek; Stock, Willem; Sunagawa, Shinichi; Toulza, Eve; Vorobev, Alexey; Leblanc, Catherine; Not, Fabrice.
Host-microbe interactions play crucial roles in marine ecosystems, but we still have very little understanding of the mechanisms that govern these relationships, the evolutionary processes that shape them, and their ecological consequences. The holobiont concept is a renewed paradigm in biology that can help describe and understand these complex systems. It posits that a host and its associated microbiota, living together in a long-lasting relationship, form the holobiont, and have to be studied together, as a coherent biological and functional unit, in order to understand the biology, ecology and evolution of the organisms. Here we discuss critical concepts and opportunities in marine holobiont research and identify key challenges in the field. We...
Tipo: Text
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00480/59209/61904.pdf

Captive bottlenose dolphins and killer whales harbor a species-specific skin microbiota that varies among individuals
Provedor de dados: 5
Autores: Chiarello, M.; Vileger, S.; Bouvier, C.; Auguet, Jean-christophe; Bouvier, T.
Marine animals surfaces host diverse microbial communities, which play major roles for host's health. Most inventories of marine animal surface microbiota have focused on corals and fishes, while cetaceans remain overlooked. The few studies focused on wild cetaceans, making difficult to distinguish intrinsic inter-and/or intraspecific variability in skin microbiota from environmental effects. We used high-throughput sequencing to assess the skin microbiota from 4 body zones of 8 bottlenose dolphins (Tursiops truncatus) and killer whales (Orcinus orca), housed in captivity (Marineland park, France). Overall, cetacean skin microbiota is more diverse than planktonic communities and is dominated by different phylogenetic lineages and functions. In addition,...
Tipo: Text
Ano: 2017
URL: https://archimer.ifremer.fr/doc/00412/52394/74753.pdf

Comparative analysis of the food webs of two intertidal mudflats during two seasons using inverse modelling: Aiguillon Cove and Brouage Mudflat, France
Provedor de dados: 5
Autores: Degre, Delphine; Leguerrier, D; Du Chatelet, E; Rzeznik, J; Auguet, Jean-christophe; Dupuy, Christine; Marquis, E; Fichet, Denis; Struski, Caroline; Joyeux, E; Sauriau, Pierre-guy; Niquil, Nathalie.
Inverse analysis was used to model the food webs of two intertidal mudflat ecosystems: Aiguillon Cove (AC) and Brouage Mudflat (BM) (south-western Atlantic coast, France). The aim of the present study is to describe and compare the functioning of these two ecosystems. The method of inverse analysis has been adapted in order to take into account, in a single calculation, two seasons: spring/summer (mid-March to mid-October) and autumn/winter (the rest of the year). Gathering all available data on the two sites, the most important gaps in knowledge were identified with the help of sensitivity analyses: they concerned mainly the exports of material by grazing fish (such as mullet Liza ramada), resuspension of microphytobenthos, and fluxes linked to microfauna...
Tipo: Text
Palavras-chave: Atlantic coast; Sensitivity analysis; Tidal flat; Inverse analysis; Steady state; Food web.
Ano: 2006
URL: http://archimer.ifremer.fr/doc/2006/publication-1863.pdf

Response of Core Microbial Consortia to Chronic Hydrocarbon Contaminations in Coastal Sediment Habitats
Provedor de dados: 5
Autores: Jeanbille, Mathilde; Gury, Jerome; Duran, Robert; Tronczynski, Jacek; Agogue, Helene; Ben Said, Olfa; Ghiglione, Jean-francois; Auguet, Jean-christophe.
Traditionally, microbial surveys investigating the effect of chronic anthropogenic pressure such as polyaromatic hydrocarbons (PAHs) contaminations consider just the alpha and beta diversity and ignore the interactions among the different taxa forming the microbial community. Here, we investigated the ecological relationships between the three domains of life (i.e., Bacteria, Archaea, and Eukarya) using 454 pyrosequencing on the 16S rRNA and 18S rRNA genes from chronically impacted and pristine sediments, along the coasts of the Mediterranean Sea (Gulf of Lion, Vermillion coast, Corsica, Bizerte lagoon and Lebanon) and the French Atlantic Ocean (Bay of Biscay and English Channel). Our approach provided a robust ecological framework for the partition of the...
Tipo: Text
Palavras-chave: Co-occurrence network; Core community; Microbial consortia; PAH; Chronic contamination; Coastal sediment.
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00355/46586/46394.pdf

Potential Effect of Freshwater Virus on the Structure and Activity of Bacterial Communities in the Marennes-Oléron Bay (France)
Provedor de dados: 5
Autores: Auguet, Jean-christophe; Montanie, Helene; Hartmann, Hans; Lebaron, P.; Casamayor, E. O.; Catala, P.; Delmas, Daniel.
Batch culture experiments using viral enrichment were conducted to test the response of a coastal bacterial community to autochthonous (i.e., co-existing) or allochthonous riverine viruses. The effects of viral infections on bacterial dynamics and activity were assessed by epifluorescence microscopy and thymidine incorporation, respectively, whereas the effect of viral infection on bacterial community composition was examined by polymerase chain reaction-single strand conformation polymorphism 16S ribosomal RNA fingerprinting. The percentages of high nucleic acid-containing cells, evaluated by flow cytometry, were significantly correlated (r (2) = 0.91, n = 12, p &lt; 0.0001) to bacterial production, making this value a good predictor of active cell...
Tipo: Text
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/publication-6636.pdf

Oyster hemolymph is a complex and dynamic ecosystem hosting bacteria, protists and viruses
Provedor de dados: 5
Autores: Dupont, Samuel; Lokmer, A.; Corre, E.; Auguet, Jean-christophe; Petton, Bruno; Toulza, E.; Montagnani, Caroline; Tanguy, G.; Pecqueur, D.; Salmeron, C.; Guillou, L.; Desnues, C.; La Scola, B.; Bou Khalil, J.; De Lorgeril, Julien; Mitta, Guillaume; Gueguen, Yannick; Escoubas, Jean Michel.
Background The impact of the microbiota on host fitness has so far mainly been demonstrated for the bacterial microbiome. We know much less about host-associated protist and viral communities, largely due to technical issues. However, all microorganisms within a microbiome potentially interact with each other as well as with the host and the environment, therefore likely affecting the host health. Results We set out to explore how environmental and host factors shape the composition and diversity of bacterial, protist and viral microbial communities in the Pacific oyster hemolymph, both in health and disease. To do so, five oyster families differing in susceptibility to the Pacific oyster mortality syndrome were reared in hatchery and transplanted into a...
Tipo: Text
Palavras-chave: Oyster genetic background; Hemolymph microbiota dynamics; Early-life microbiota; Trans-kingdom interactions; Crassostrea gigas; Within-host ecosystem.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00627/73916/73254.pdf

A strong link between marine microbial community composition and function challenges the idea of functional redundancy
Provedor de dados: 5
Autores: Galand, Pierre E.; Pereira, Olivier; Hochart, Corentin; Auguet, Jean-christophe; Debroas, Didier.
Marine microbes have tremendous diversity, but a fundamental question remains unanswered: why are there so many microbial species in the sea? The idea of functional redundancy for microbial communities has long been assumed, so that the high level of richness is often explained by the presence of different taxa that are able to conduct the exact same set of metabolic processes and that can readily replace each other. Here, we refute the hypothesis of functional redundancy for marine microbial communities by showing that a shift in the community composition altered the overall functional attributes of communities across different temporal and spatial scales. Our metagenomic monitoring of a coastal northwestern Mediterranean site also revealed that diverse...
Tipo: Text
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00459/57118/59050.pdf

Ecological Specialization Within a Carnivorous Fish Family Is Supported by a Herbivorous Microbiome Shaped by a Combination of Gut Traits and Specific Diet
Provedor de dados: 5
Autores: Escalas, Arthur; Auguet, Jean-christophe; Avouac, Amandine; Seguin, Raphaël; Gradel, Antoine; Borrossi, Lucie; Villéger, Sébastien.
Animals have been developing key associations with micro-organisms through evolutionary processes and ecological diversification. Hence, in some host clades, phylogenetic distance between hosts is correlated to dissimilarity in microbiomes, a pattern called phylosymbiosis. Teleost fishes, despite being the most diverse and ancient group of vertebrates, have received little attention from the microbiome perspective and our understanding of its determinants is currently limited. In this study, we assessed the gut microbiome of 12 co-occurring species of teleost representing a large breadth of ecological diversity and originating from a single family (i.e., the Sparidae). We tested how host evolutionary history, diet composition and morphological traits are...
Tipo: Text
Palavras-chave: Fish gut microbiome; Sparidae; Phylosymbiosis; Morphological traits; Diet; Herbivory; Ecological outlier.
Ano: 2021
URL: https://archimer.ifremer.fr/doc/00682/79408/81955.pdf