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Auteur Reichel, K.; Masson, J.-P.; Malrieu, F.; Arnaud-Haond, S.; Stoeckel, S.
Titre Rare sex or out of reach equilibrium? The dynamics of F-IS in partially clonal organisms Type Article scientifique
Année 2016 Publication Revue Abrégée (up) BMC Genet.
Volume 17 Numéro Pages 76
Mots-Clés consequences; diversity; evolution; genetic diversity; genetic-structure; Heterozygote excess; hybridization; Inbreeding coefficient; loci; Mating system; microsatellite primers; mutation; Parthenogenesis; Partial asexuality; population-genetics; reproduction
Résumé Background: Partially clonal organisms are very common in nature, yet the influence of partial asexuality on the temporal dynamics of genetic diversity remains poorly understood. Mathematical models accounting for clonality predict deviations only for extremely rare sex and only towards mean inbreeding coefficient (F-IS) over bar < 0. Yet in partially clonal species, both F-IS < 0 and F-IS > 0 are frequently observed also in populations where there is evidence for a significant amount of sexual reproduction. Here, we studied the joint effects of partial clonality, mutation and genetic drift with a state-and-time discrete Markov chain model to describe the dynamics of F-IS over time under increasing rates of clonality. Results: Results of the mathematical model and simulations show that partial clonality slows down the asymptotic convergence to F-IS = 0. Thus, although clonality alone does not lead to departures from Hardy-Weinberg expectations once reached the final equilibrium state, both negative and positive F-IS values can arise transiently even at intermediate rates of clonality. More importantly, such “transient” departures from Hardy Weinberg proportions may last long as clonality tunes up the temporal variation of F-IS and reduces its rate of change over time, leading to a hyperbolic increase of the maximal time needed to reach the final mean (F-IS,F-infinity) over bar value expected at equilibrium. Conclusion: Our results argue for a dynamical interpretation of F-IS in clonal populations. Negative values cannot be interpreted as unequivocal evidence for extremely scarce sex but also as intermediate rates of clonality in finite populations. Complementary observations (e.g. frequency distribution of multiloci genotypes, population history) or time series data may help to discriminate between different possible conclusions on the extent of clonality when mean (F-IS) over bar values deviating from zero and/or a large variation of F-IS over loci are observed.
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Langue English Langue du Résumé Titre Original
Éditeur de collection Titre de collection Titre de collection Abrégé
Volume de collection Numéro de collection Edition
ISSN 1471-2156 ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 1648
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Auteur Ben Lamine, Y.; Pringault, O.; Aissi, M.; Ensibi, C.; Mahmoudi, E.; Daly Yahia Kefi, O.; Daly Yahia, M.N.
Titre Environmental controlling factors of copepod communities in the Gulf of Tunis (south western Mediterranean Sea) Type Article scientifique
Année 2015 Publication Revue Abrégée (up) Cahiers de Biologie Marine
Volume 56 Numéro 3 Pages 213-229
Mots-Clés Competition; Copepod diversity; multivariate analysis; Salinity; Temperature; Top-down control
Résumé The copepod community structure and the distribution of the main groups of zooplankton were studied along an inshore-offshore gradient in the Gulf of Tunis during the rainy and dry seasons of 2007-2008. Hydrological parameters were also measured to assess the potential role of abiotic and biotic factors in the distribution of copepod species. The copepod community in the Gulf of Tunis comprises 86 species dominated by Paracalanus parvus, Clausocalanus lividus, Centropages kroyeri and Acartia clausi. Time had a greater influence than space (horizontal and vertical gradients) in shaping the copepod community structure with a significant influence of the seasons; winter (cold and rainy) resulted in hydrological conditions that were strongly different from those observed in summer (warm and dry). These hydrological differences were concomitant with changes in the community structure, with a high copepod diversity observed in winter while the summer period was characterized by a low specific richness and the dominance of a few species, Centropages kroyeri and Paracalanus parvus along the inshore-offshore gradient and Paracalanus aculeatus along the vertical. Canonical correspondence analysis showed that temperature, salinity and to a lesser extent chlorophyll a were the most important environmental factors structuring the copepod community. Interestingly, temperature and salinity showed a negative significant correlation with copepod specific richness. Competition with grazers (cladoceran) as well as top down control by predators (chaetognaths and siphonophors) were also identified as key factors for the copepod community structure.
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Éditeur de collection Titre de collection Titre de collection Abrégé
Volume de collection Numéro de collection Edition
ISSN 0007-9723 ISBN Médium
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Notes WOS:000358550200003 Approuvé pas de
Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 1324
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Auteur Goni-Urriza, M.; Moussard, H.; Lafabrie, H.; Carré, C.; Bouvy, M.; Sakka Hlaili, A.; Pringault, O.
Titre Consequences of contamination on the interactions between phytoplankton and bacterioplankton Type Article scientifique
Année 2018 Publication Revue Abrégée (up) Chemosphere
Volume 195 Numéro Pages 212-222
Mots-Clés bizerte lagoon; bacterial communities; polycyclic aromatic-hydrocarbons; surface sediments; functional diversity; ecosystem; sediment resuspension; coastal lagoon; nutrient enrichment; tropical lagoon
Résumé Sediment resuspension can provoke strong water enrichment in nutrients, contaminants, and microorganisms. Microcosm incubations were performed in triplicate for 96 h, with lagoon and offshore waters incubated either with sediment elutriate or with an artificial mixture of contaminants issued from sediment resuspension. Sediment elutriate provoked a strong increase in microbial biomass, with little effects on the phytoplankton and bacterioplankton community structures. Among the pool of contaminants released, few were clearly identified as structuring factors of phytoplanktdn and bacterioplankton communities, namely simazine, Cu, Sn, Ni, and Cr. Effects were more pronounced in the offshore waters, suggesting a relative tolerance of the lagoon microbial communities to contamination. The impacts of contamination on the microbial community structure were direct or indirect, depending on the nature and the strength of the interactions between phytoplankton and bacterioplankton. (C) 2017 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 0045-6535 ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 2265
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Auteur Cormier-Salem, M.-C.; Van Trai, N.; Burgos, A.; Durand, J.-D.; Bettarel, Y.; Klein, J.; Duc Huy, H.; Panfili, J.
Titre The mangrove's contribution to people: Interdisciplinary pilot study of the Can Gio Mangrove Biosphere Reserve in Viet Nam Type Article scientifique
Année 2017 Publication Revue Abrégée (up) Comptes Rendus Geoscience
Volume 349 Numéro 6 Pages 341-350
Mots-Clés Mangrove; Biodiversity; Coastal environment; Ecosystem services; Interdisciplinary framework; Local knowledge
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Volume de collection Numéro de collection Edition
ISSN 1631-0713 ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 2231
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Auteur Magris, R.A.; Andrello, M.; Pressey, R.L.; Mouillot, D.; Dalongeville, A.; Jacobi, M.N.; Manel, S.
Titre Biologically representative and well-connected marine reserves enhance biodiversity persistence in conservation planning Type Article scientifique
Année 2018 Publication Revue Abrégée (up) Conserv. Lett.
Volume 11 Numéro 4 Pages Unsp-e12439
Mots-Clés biodiversity conservation; climate-change; coral-reefs; design; larval dispersal; marine protected areas; marine reserve design; networks; population connectivity; protected areas; spatial planning; spatial prioritization
Résumé Current methods in conservation planning for promoting the persistence of biodiversity typically focus on either representing species geographic distributions or maintaining connectivity between reserves, but rarely both, and take a focal species, rather than a multispecies, approach. Here, we link prioritization methods with population models to explore the impact of integrating both representation and connectivity into conservation planning for species persistence. Using data on 288 Mediterranean fish species with varying conservation requirements, we show that: (1) considering both representation and connectivity objectives provides the best strategy for enhanced biodiversity persistence and (2) connectivity objectives were fundamental to enhancing persistence of small-ranged species, which are most in need of conservation, while the representation objective benefited only wide-ranging species. Our approach provides a more comprehensive appraisal of planning applications than approaches focusing on either representation or connectivity, and will hopefully contribute to build more effective reserve networks for the persistence of biodiversity.
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Langue English Langue du Résumé Titre Original
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Volume de collection Numéro de collection Edition
ISSN 1755-263x ISBN Médium
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Numéro d'Appel MARBEC @ alain.herve @ collection 2423
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