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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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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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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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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 Xuereb, A.; D'Aloia, C.C.; Andrello, M.; Bernatchez, L.; Fortin, M.-J.
Titre Incorporating putatively neutral and adaptive genomic data into marine conservation planning Type Article scientifique
Année 2020 Publication Revue Abrégée (up) Conserv. Biol.
Volume Numéro Pages
Mots-Clés adaptation; adaptive genetic variation; area marina protegida; cambio climatico; climate change; climate-change; conservation genetics; diversity; future; genetic-variation; genetica de la conservacion; marine protected area; markers; priorizacion de la conservacion espacial; reserves; size; spatial conservation prioritization; variacion genetica adaptativa
Résumé The availability of genomic data for an increasing number of species makes it possible to incorporate evolutionary processes into conservation plans. Recent studies show how genetic data can inform spatial conservation prioritization (SCP), but they focus on metrics of diversity and distinctness derived primarily from neutral genetic data sets. Identifying adaptive genetic markers can provide important information regarding the capacity for populations to adapt to environmental change. Yet, the effect of including metrics based on adaptive genomic data into SCP in comparison to more widely used neutral genetic metrics has not been explored. We used existing genomic data on a commercially exploited species, the giant California sea cucumber (Parastichopus californicus), to perform SCP for the coastal region of British Columbia (BC), Canada. Using a RAD-seq data set for 717P. californicusindividuals across 24 sampling locations, we identified putatively adaptive (i.e., candidate) single nucleotide polymorphisms (SNPs) based on genotype-environment associations with seafloor temperature. We calculated various metrics for both neutral and candidate SNPs and compared SCP outcomes with independent metrics and combinations of metrics. Priority areas varied depending on whether neutral or candidate SNPs were used and on the specific metric used. For example, targeting sites with a high frequency of warm-temperature-associated alleles to support persistence under future warming prioritized areas in the southern coastal region. In contrast, targeting sites with high expected heterozygosity at candidate loci to support persistence under future environmental uncertainty prioritized areas in the north. When combining metrics, all scenarios generated intermediate solutions, protecting sites that span latitudinal and thermal gradients. Our results demonstrate that distinguishing between neutral and adaptive markers can affect conservation solutions and emphasize the importance of defining objectives when choosing among various genomic metrics for SCP.
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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 0888-8892 ISBN Médium
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Notes WOS:000577896200001 Approuvé pas de
Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 2894
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