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Auteur Paiola, M.; Knigge, T.; Duflot, A.; Pinto, P.I.S.; Farcy, E.; Monsinjon, T.
Titre Oestrogen, an evolutionary conserved regulator of T cell differentiation and immune tolerance in jawed vertebrates? Type Article scientifique
Année 2018 Publication (up) Revue Abrégée Dev. Comp. Immunol.
Volume 84 Numéro Pages 48-61
Mots-Clés bass dicentrarchus-labrax; danio-rerio; dendritic cells; estradiol; european sea-bass; Gamma-delta T cell; gene-expression; Head-kidney; receptor modulators; Regulatory T cell; reproductive-cycle; Spleen; Teleost; thymic epithelial-cells; Thymus; zebrafish
Résumé In teleosts, as in mammals, the immune system is tightly regulated by sexual steroid hormones, such as oestrogens. We investigated the effects of 17 beta-oestradiol on the expression of several genes related to T cell development and resulting T cell subpopulations in sea bass, Dicentrarchus labrax, for a primary lymphoid organ, the thymus, and two secondary lymphoid organs, the head-kidney and the spleen. In parallel, the oxidative burst capacity was assessed in leucocytes of the secondary lymphoid organs. Apoptosis- and proliferation-related genes, indicative of B and T cell clonal selection and lymphoid progenitor activity, were not affected by elevated oestrogen-levels. Sex-related oestrogen-responsiveness in T cell and antigen-presenting cell markers was observed, the expression of which was differentially induced by oestrogen-exposure in the three lymphoid organs. Remarkably, in the spleen, oestrogen increased regulatory T cell-related gene expression was associated with a decrease in oxidative burst capacity. To the best of our knowledge, this study indicates for the first time that physiological levels of oestrogen are likely to promote immune tolerance by modulating thymic function (i.e., T cell development and output) and peripheral T cells in teleosts, similar to previously reported oestrogenic effects in mammals. (C) 2018 Elsevier Ltd. All rights reserved.
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ISSN 0145-305x ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 2340
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Auteur Duval, C.; Thomazeau, S.; Drelin, Y.; Yepremian, C.; Bouvy, M.; Couloux, A.; Troussellier, M.; Rousseau, F.; Bernard, C.
Titre Phylogeny and salt-tolerance of freshwater Nostocales strains: Contribution to their systematics and evolution Type Article scientifique
Année 2018 Publication (up) Revue Abrégée Harmful Algae
Volume 73 Numéro Pages 58-71
Mots-Clés baltic sea; bloom; comb. nova; Cyanobacteria; dolichospermum; genera anabaena; genetics analysis; great oxidation event; hetR; Morphology; nijH; Nostocaceae; Phylogeny; Physiology; planktonic cyanobacteria; polyphasic approach; Polyphasic approach; Salt-tolerance; toxin production
Résumé Phylogenetic relationships among heterocytous genera (the Nostocales order) have been profoundly modified since the use of polyphasic approaches that include molecular data. There is nonetheless still ample scope for improving phylogenetic delineations of genera with broad ecological distributions, particularly by integrating specimens from specific or up-to-now poorly sampled habitats. In this context, we studied 36 new isolates belonging to Chrysosporum, Dolichospermum, Anabaena, Anabaenopsis, and Cylindrospermopsis from freshwater ecosystems of Burkina-Faso, Senegal, and Mayotte Island. Studying strains from these habitats is of particular interest as we suspected different range of salt variations during underwent periods of drought in small ponds and lakes. Such salt variation may cause different adaptation to salinity. We then undertook a polyphasic approach, combining molecular phylogenies, morphological analyses, and physiological measurements of tolerance to salinity. Molecular phylogenies of 117 Nostocales sequences showed that the 36 studied strains were distributed in seven lineages: Dolichospermum, Chrysosporum, Cylindrospermopsis Raphidiopsis, Anabaenopsis, Anabaena sphaerica var tenuis/Sphaerospermopsis, and two independent Anabaena sphaerica lineages. Physiological data were congruent with molecular results supporting the separation into seven lineages. In an evolutionary context, salinity tolerance can be used as an integrative marker to reinforce the delineation of some cyanobacterial lineages. The history of this physiological trait contributes to a better understanding of processes leading to the divergence of cyanobacteria. In this study, most of the cyanobacterial strains isolated from freshwater environments were salt-tolerant, thus suggesting this trait constituted an ancestral trait of the heterocytous cyanobacteria and that it was probably lost two times secondarily and independently in the ancestor of Dolichospermum and of Cylindrospermopsis. (C) 2018 Elsevier B.V. All rights reserved.
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Éditeur de collection Titre de collection Titre de collection Abrégé
Volume de collection Numéro de collection Edition
ISSN 1568-9883 ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 2341
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Auteur Kara, M.H.; Lacroix, D.; Rey-Valette, H.; Mathe, S.; Blancheton, J.P.
Titre Dynamics of Research in Aquaculture in North Africa and Support for Sustainable Development and Innovation Type Article scientifique
Année 2018 Publication (up) Revue Abrégée Rev. Fish. Sci. Aquac..
Volume 26 Numéro 3 Pages 309-318
Mots-Clés agriculture; aquaculture; development; impact; Mediterranean; North Africa; research; sustainability
Résumé This article examines the supporting role of research in the development of marine aquaculture in the aquaculture-producing countries of North Africa: Algeria, Egypt, Morocco, and Tunisia. Research plays a significant role not only in the support of the development of the sector, but also in the evolution toward sustainable aquaculture practices and a better integrated management of this activity. This analysis was conducted as part of the Aquamed project whose main objective was to create a multi-stakeholder platform (institutional decision makers, producers, researchers, NGOs, etc.) to strengthen cooperation and stimulate innovation for sustainable aquaculture in the Mediterranean. In particular, the Aquamed project aimed at an exploration of forms of collaboration through the identification of sub-groups of countries whose similarity of situations or challenges could help promote dialogue. The study of aquaculture and research in the countries reveals the contrasted situations between Egypt and the three western North African countries (Algeria, Morocco, and Tunisia). The analysis of research capabilities was carried out on the basis of several indicators, which were compiled from a survey among the relevant main institutes in the various countries, as well as from bibliometric research on the publications produced in the field of aquaculture. Beyond the differences identified among the countries, the analysis emphasizes the similarity of the challenges and the benefits of strengthening collaborations on a sub-regional scale.
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Volume de collection Numéro de collection Edition
ISSN 2330-8249 ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 2342
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Auteur Coll, M.; Steenbeek, J.
Titre Standardized ecological indicators to assess aquatic food webs: The ECOIND software plug-in for Ecopath with Ecosim models Type Article scientifique
Année 2017 Publication (up) Revue Abrégée Environ. Modell. Softw.
Volume 89 Numéro Pages 120-130
Mots-Clés biodiversity; Conservation; Ecological standardized indicators; Ecopath with Ecosim; ecospace; Ecosystem indicators; Environmental status; Fisheries management; Food web models; impacts; index; marine ecosystems; Mediterranean Sea; network analysis; ocean; Software plug-in
Résumé Ecological indicators are useful tools to analyse and communicate historical changes in ecosystems and plausible future scenarios while evaluating environmental status. Here we introduce a new plug-in to the Ecopath with Ecosim (EwE) food web modelling approach, which is widely used to quantitatively describe aquatic ecosystems. The plug-in (ECOIND) calculates standardized ecological indicators. We describe the primary functionality of ECOIND and provide an example of its application in both static and temporal-spatial dynamic modelling, while we highlight several related features including a new taxonomy input database (species traits) and the ability to analyse input uncertainty on output results. ECOIND adds new capabilities to the widely used EwE food web modelling approach and enables broadening its applications into biodiversity and conservation-based frameworks to contribute to integrated ecosystem analyses. (C) 2016 Elsevier Ltd. All rights reserved.
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Langue English Langue du Résumé Titre Original
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Volume de collection Numéro de collection Edition
ISSN 1364-8152 ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 2088
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Auteur Mari, X.; Lefevre, J.; Torreton, J.P.; Bettarel, Y.; Pringault, O.; Rochelle-Newall, E.; Marchesiello, P.; Menkes, C.; Rodier, M.; Migon, C.; Motegi, C.; Weinbauer, M.G.; Legendre, L.
Titre Effects of soot deposition on particle dynamics and microbial processes in marine surface waters Type Article scientifique
Année 2014 Publication (up) Revue Abrégée Global Biogeochemical Cycles
Volume 28 Numéro 7 Pages 662-678
Mots-Clés aerosols; black carbon; coral-reef lagoon; dissolved organic-matter; new-caledonia; ocean; Sea; sediments; size spectra; tep
Résumé Large amounts of soot are continuously deposited on the global ocean. Even though significant concentrations of soot particles are found in marine waters, the effects of these aerosols on ocean ecosystems are currently unknown. Using a combination of in situ and experimental data, and results from an atmospheric transport model, we show that the deposition of soot particles from an oil-fired power plant impacted biogeochemical properties and the functioning of the pelagic ecosystem in tropical oligotrophic oceanic waters off New Caledonia. Deposition was followed by a major increase in the volume concentration of suspended particles, a change in the particle size spectra that resulted from a stimulation of aggregation processes, a 5% decrease in the concentration of dissolved organic carbon (DOC), a decreases of 33 and 23% in viral and free bacterial abundances, respectively, and a factor similar to 2 increase in the activity of particle-attached bacteria suggesting that soot introduced in the system favored bacterial growth. These patterns were confirmed by experiments with natural seawater conducted with both soot aerosols collected in the study area and standard diesel soot. The data suggest a strong impact of soot deposition on ocean surface particles, DOC, and microbial processes, at least near emission hot spots.
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ISSN 0886-6236 ISBN Médium
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Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 554
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