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Auteur Reichel, K.; Masson, J.-P.; Malrieu, F.; Arnaud-Haond, S.; Stoeckel, S. doi  openurl
  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  
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  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 Pirog, A.; Blaison, A.; Jaquemet, S.; Soria, M.; Magalon, H. url  doi
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  Titre Isolation and characterization of 20 microsatellite markers from Carcharhinus leucas (bull shark) and cross-amplification in Galeocerdo cuvier (tiger shark), Carcharhinus obscurus (dusky shark) and Carcharhinus plumbeus (sandbar shark) Type Article scientifique
  Année 2015 Publication Revue Abrégée (up) Conservation Genet Resour  
  Volume 7 Numéro 1 Pages 121-124  
  Mots-Clés Animal Anatomy / Morphology / Histology; Bull shark; Carcharhinus leucas; Carcharhinus obscurus; Carcharhinus plumbeus; Conservation Biology/Ecology; Evolutionary Biology; Galeocerdo cuvier; Microsatellite; Plant Sciences  
  Résumé With the development of genetics methods, it becomes possible to study the population structure and some aspects of the reproductive behaviour of endangered sharks. Here we describe the isolation of 20 polymorphic microsatellite markers in the bull shark Carcharhinus leucas (Carcharhinidae) and their characteristics. Two to 10 alleles per locus were detected. Observed and expected heterozygosities ranged from 0.00 to 0.78 and from 0.05 to 0.80, respectively. Four markers showed deviations from Hardy–Weinberg equilibrium; among them, three showed presence of null alleles. No linkage disequilibrium was detected among any of the loci. Moreover, four, 11 and 19 of these 20 markers successfully cross-amplified in the tiger shark Galeocerdo cuvier, the sandbar shark Carcharhinus plumbeus and the dusky shark Carcharhinus obscurus, respectively.  
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  Volume de collection Numéro de collection Edition  
  ISSN 1877-7252, 1877-7260 ISBN Médium  
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  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 1260  
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Auteur Dalongeville, A.; Andrello, M.; Mouillot, D.; Albouy, C.; Manel, S. doi  openurl
  Titre Ecological traits shape genetic diversity patterns across the Mediterranean Sea: a quantitative review on fishes Type Article scientifique
  Année 2016 Publication Revue Abrégée (up) J. Biogeogr.  
  Volume 43 Numéro 4 Pages 845-857  
  Mots-Clés atlantic bluefin tuna; bass dicentrarchus-labrax; climate-change; cod gadus-morhua; ecological traits; effective population-size; genetic diversity; gilthead sea; life-history traits; marine fishes; marine populations; Mediterranean Sea; microsatellite markers; microsatellites; mitochondrial; mitochondrial DNA; molecular markers; population genetics  
  Résumé AimWe set out to identify the determinants of the variation in genetic diversity among fish species and test whether multi-species genetic diversity is randomly distributed in space. LocationMediterranean Sea. MethodsWe collected genetic diversity data from 39 published studies on Mediterranean fishes (31 species) along with the spatial coordinates of the sampling sites. We focused on microsatellite heterozygosity (151 data points) and mitochondrial haplotype diversity (201 data points). We used linear regressions to link genetic diversity and 11 ecological traits. We also tested for spatial autocorrelation and trends in the residuals. ResultsAmong-species variation in microsatellite heterozygosity was explained by three ecological traits: vertical distribution, migration type and body length. Variation in mitochondrial haplotype diversity was also explained by vertical distribution and migration type, and by reproductive strategy (semelparity). However, vertical distribution and migration type showed opposite effects on microsatellites and mitochondrial diversity. After accounting for the effects of ecological traits, no spatial pattern was detected, except for one of the species considered. Main conclusionsEcological factors explain an important proportion of the among-species genetic diversity. These results suggest that life history strategies of the species influence the variation of microsatellite diversity indirectly through their effect on effective population size, while the spatial variations of genetic diversity seem to be too complex to be identified in our analysis. We found very different effects of traits on mitochondrial and nuclear DNA diversity, which can be explained by the specificities of mitochondrial DNA (absence of recombination, maternal inheritance and non-neutrality).  
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  ISSN 0305-0270 ISBN Médium  
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  Numéro d'Appel MARBEC @ alain.herve @ collection 1627  
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Auteur ARNAUD-HAOND, S.; MOALIC, Y.; HERNANDEZ-GARCIA, E.; EGUILUZ, V.M.; ALBERTO, F.; SERRAO, E.A.; DUARTE, C.M. url  openurl
  Titre Disentangling the Influence of Mutation and Migration in Clonal Seagrasses Using the Genetic Diversity Spectrum for Microsatellites Type Article scientifique
  Année 2014 Publication Revue Abrégée (up) Journal Of Heredity  
  Volume 105 Numéro 4 Pages 532-541  
  Mots-Clés clonality; genetic divergence; Genetic Diversity Spectrum; microsatellites; Seagrass; stepwise mutation  
  Résumé The recurrent lack of isolation by distance reported at regional scale in seagrass species was recently suggested to stem from stochastic events of large-scale dispersal. We explored the usefulness of phylogenetic information contained in microsatellite loci to test this hypothesis by using the Genetic Diversity Spectrum (GDS) on databases containing, respectively, 7 and 9 microsatellites genotypes for 1541 sampling units of Posidonia oceanica and 1647 of Cymodocea nodosa. The simultaneous increase of microsatellite and geographic distances that emerges reveals a coherent pattern of isolation by distance in contrast to the chaotic pattern previously described using allele frequencies, in particular, for the long-lived P. oceanica. These results suggest that the lack of isolation by distance, rather than the resulting from rare events of large-scale dispersal, reflects at least for some species a stronger influence of mutation over migration at the scale of the distribution range. The global distribution of genetic polymorphism may, therefore, result predominantly from ancient events of step-by-step (re)colonization followed by local recruitment and clonal growth, rather than contemporary gene flow. The analysis of GDS appears useful to unravel the evolutionary forces influencing the dynamics and evolution at distinct temporal and spatial scales by accounting for phylogenetic information borne by microsatellites, under an appropriate mutation model. This finding adds nuance to the generalization of the influence of large-scale dispersal on the dynamics of seagrasses.  
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  Volume de collection Numéro de collection Edition  
  ISSN 0022-1503 ISBN Médium  
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  Numéro d'Appel MARBEC @ isabelle.vidal-ayouba @ collection 1138  
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Auteur Viricel, A.; Simon-Bouhet, B.; Ceyrac, L.; Dulau-Drouot, V.; Berggren, P.; Amir, O.A.; Jiddawi, N.S.; Mongin, P.; Kiszka, J.J. doi  openurl
  Titre Habitat availability and geographic isolation as potential drivers of population structure in an oceanic dolphin in the Southwest Indian Ocean Type Article scientifique
  Année 2016 Publication Revue Abrégée (up) Mar. Biol.  
  Volume 163 Numéro 10 Pages 219  
  Mots-Clés biologically meaningful; bottle-nosed dolphins; genetic differentiation; marine populations; megaptera-novaeangliae; microsatellite loci; mozambique channel; spinner dolphins; stenella-longirostris; tursiops-truncatus  
  Résumé Delphinid populations show highly variable patterns of genetic diversity and population structure. Previous studies indicate that habitat discontinuities and geographic isolation are major drivers of population division in cetaceans. Spinner dolphins (Stenella longirostris) are distributed in all tropical oceans, but they are particularly common around islands and atolls. This species occurs in shallow waters at daytime to rest and socialise, and feeds on offshore mesopelagic prey overnight. Here, we investigated the genetic population structure of spinner dolphins in the Southwest Indian Ocean along a west-east geographic gradient, from eastern Africa to the Mascarene archipelago. We combined analyses of 12 microsatellite loci, mtDNA control region sequences, and sighting data to assess genetic differentiation and characterise habitat preferences of these populations. Significant genetic structure among the three sampled sites (Zanzibar, Mayotte and La Reunion) was observed using both types of molecular markers. Overall, our results indicate that geographic isolation and potentially other factors, such as shallow-water habitats to rest and socialise, may be important drivers of the genetic population structure of insular spinner dolphins in this region.  
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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 0025-3162 ISBN Médium  
  Région Expédition Conférence  
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  Numéro d'Appel MARBEC @ alain.herve @ collection 1700  
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