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'microsatellite' 
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Partager le résultat de cette rechercheMicrosatellite allele sizes : a simple test to assess their significance on genetic differentiation / Olivier J. Hardy in Genetics, vol. 163, n°4 (Année 2003)
Titre : Microsatellite allele sizes : a simple test to assess their significance on genetic differentiation Auteurs : Olivier J. Hardy, Auteur ; Nathalie Charbonnel, Auteur ; Hélène Fréville, Auteur ; Myriam Heuertz, Auteur Année de publication : 2003 Article en page(s) : pp. 1467-82 Langues : Anglais (eng) Mots-clés : diversité génétique marqueur génétique microsatellite Résumé : "The mutation process at microsatellite loci typically occurs at high rates and with stepwise changes in allele sizes, features that may introduce bias when using classical measures of population differentiation based on allele identity (e.g., F(ST), Nei's Ds genetic distance). Allele size-based measures of differentiation, assuming a stepwise mutation process [e.g., Slatkin's R(ST), Goldstein et al.'s (deltamu)(2)], may better reflect differentiation at microsatellite loci, but they suffer high sampling variance. The relative efficiency of allele size- vs. allele identity-based statistics depends on the relative contributions of mutations vs. drift to population differentiation. We present a simple test based on a randomization procedure of allele sizes to determine whether stepwise-like mutations contributed to genetic differentiation. This test can be applied to any microsatellite data set designed to assess population differentiation and can be interpreted as testing whether F(ST) = R(ST). Computer simulations show that the test efficiently identifies which of F(ST) or R(ST) estimates has the lowest mean square error. A significant test, implying that R(ST) performs better than F(ST), is obtained when the mutation rate, mu, for a stepwise mutation process is (a) >/= m in an island model (m being the migration rate among populations) or (b) >/= 1/t in the case of isolated populations (t being the number of generations since population divergence). The test also informs on the efficiency of other statistics used in phylogenetical reconstruction [e.g., Ds and (deltamu)(2)], a nonsignificant test meaning that allele identity-based statistics perform better than allele size-based ones. This test can also provide insights into the evolutionary history of populations, revealing, for example, phylogeographic patterns, as illustrated by applying it on three published data sets." (source : auteurs) Note de contenu : Cet article discute de l'utilisation des marqueurs génétiques microsatellites pour évaluer la différenciation génétique entre populations. Le principal objectif de l'étude est de proposer un test simple basé sur la permutation des tailles des allèles pour déterminer si les mutations de type stepwise (à pas fixes) contribuent à la différenciation génétique.
Type de publication : périodique Référence biblio : Hardy O., Charbonnel N., Fréville H., Heuertz M., 2003 - Microsatellite allele sizes : a simple test to assess their significance on genetic differentiation. Genetics, 163 (4) : 1467-82. ID PMB : 72267 DOI : 10.1093/genetics/163.4.1467 Permalink : http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=72267
in Genetics > vol. 163, n°4 (Année 2003) . - pp. 1467-82[article]Exemplaires(0)
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Titre : Fine-scale phylogeographical analysis of Mediterranean Anacamptis palustris (Orchidaceae) populations based on chloroplast minisatellite and microsatellite variation Auteurs : Salvatore Cozzolino, Auteur ; D. Cafasso, Auteur ; G. Pellegrino, Auteur ; Aldo Musacchio, Auteur ; Alex Widmer, Auteur Année de publication : 2003 Article en page(s) : pp. 2783-92 Langues : Anglais (eng) Catégories : [Espèces (in biblio)] Orchis palustris Mots-clés : diversité génétique microsatellite minisatellite phylogéographie Note de contenu : Cet article porte sur l'histoire phylogéographique de l'orchidée rare Anacamptis palustris (famille des Orchidaceae). Pour reconstruire cette histoire, des loci minisatellites et microsatellites chloroplastiques hautement polymorphes ont été utilisés. L'étude a permis de clarifier la distribution historique et la diversité génétique de Anacamptis palustris à travers l'Europe méditerranéenne, en révélant des lignées distinctes et des modèles de flux de gènes entre les populations. Les marqueurs microsatellites et minisatellites chloroplastiques se sont avérés utiles pour fournir des informations détaillées sur les relations phylogéographiques à différentes échelles géographiques. Type de publication : périodique Référence biblio : Cozzolino S., Cafasso D., Pellegrino G., Musacchio A., Widmer A., 2003 - Fine-scale phylogeographical analysis of Mediterranean Anacamptis palustris (Orchidaceae) populations based on chloroplast minisatellite and microsatellite variation. Molecular Ecology, 12 (10) : 2783-92. ID PMB : 72303 Permalink : http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=72303
in Molecular Ecology > vol. 12, n°10 (Année 2003) . - pp. 2783-92[article]Exemplaires(0)
Disponibilité aucun exemplaire Elm clone identification and the conundrum of the slow spread of Dutch Elm Disease on the Isle of Man / M. Coleman in New Journal of botany, vol. 6, n°2-3 (Année 2016)
Titre : Elm clone identification and the conundrum of the slow spread of Dutch Elm Disease on the Isle of Man Type de document : texte imprimé Auteurs : M. Coleman, Auteur ; S.W. A'Hara, Auteur ; P.R. Tomlinson, Auteur ; P.J. Davey, Auteur Année de publication : 2016 Article en page(s) : pp. 79-89 Langues : Anglais (eng) Catégories : [Espèces (in biblio)] Ulmaceae
[Espèces (in biblio)] UlmusMots-clés : génétique microsatellite Résumé : "This study was undertaken as part of a review of Ulmus L. for the forthcoming Flora of the Isle of Man. We have adopted molecular and morphological methods to reassess the identity of Ulmus on the Isle of Man and to explore the possibility that past records of English Elm, a single genotype cultivar called U. minor ‘Atinia’, were misidentifications. First, we utilised seven DNA microsatellite markers to test clone identity in a collection of 23 elms from across the Isle of Man. Sixteen samples were matched to a reference sample of Dutch Elm, U. × hollandica ‘Major’, and one sample was matched to a reference sample of English Elm. In parallel, we appraised a method employed to identify English Elm using a leaf shape metric, and found that leaf width divided by length values > 0.69 are indicative of this clone. Both molecular and morphological results in this study highlight that Dutch Elm has been misidentified as English Elm in the past, and that English Elm may in fact be a rare occurrence on the Island. The susceptibility of U. × hollandica ‘Major’ to Dutch Elm Disease suggests that the unusually slow spread of the disease on the Island is unlikely to be the result of local disease resistance in the elm population. One possibility that we explore is that the Scolytus beetle vector may experience suboptimal climatic conditions that could be limiting its dispersal, thereby reducing the rate of spread of infection." (source : auteurs) Type de publication : périodique Référence biblio : Coleman M., A'Hara S.-W., Tomlinson P.-R., Davey P.-J., 2016 - Elm clone identification and the conundrum of the slow spread of Dutch Elm Disease on the Isle of Man. New Journal of botany, 6 : 79-89. ID PMB : 65353 Permalink : http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=65353
in New Journal of botany > vol. 6, n°2-3 (Année 2016) . - pp. 79-89[article]Exemplaires(1)
Cote Localisation Disponibilité P0130-5 Brest Exclu du prêt
Titre : Genetic consequences of long-term isolation for the last French population of Eryngium viviparum (Apiaceae) Type de document : texte imprimé Auteurs : Pauline Rascle, Auteur ; Elodie Flaven, Auteur ; Frédéric Bioret, Auteur ; Sylvie Magnanon, Auteur ; Erwan Glemarec, Auteur ; Sébastien Gallet, Auteur ; Eric Imbert, Auteur Année de publication : 2019 Article en page(s) : pp. 285-298 Langues : Anglais (eng) Catégories : [Espèces (in biblio)] Eryngium viviparum Mots-clés : conservation génétique plante menacée microsatellite Résumé : "Eryngium viviparum (Apiaceae) is an endangered endemic plant of the Atlantic region of Europe, growing in seasonally flooded sites, and is characterized by a highly disjunct distribution. It occurs in just a few sites in the north-western part of the Iberian Peninsula and in a single locality in France. To improve the conservation status of E. viviparum in France, a conservation programme has been implemented to reintroduce the species. Before considering such an operation, genetic studies were conducted to determine the genetic status of the last French population and to identify the genetic source that should be considered for the best reintroduction strategy. Using microsatellite markers, we documented the genetic structure of the last French population and compared its genetic diversity with that of ten Iberian populations, which cover the three geographical regions where the species occurs. As expected, the French population of E. viviparum shows low genetic diversity due to a bottleneck and geographical isolation. The evolutionary potential appears low, with no private alleles in this population. Furthermore, this population is highly differentiated from the Iberian populations in terms of genetic variation and ecological niche. These results bring new questions regarding the conservation of E. viviparum in France, especially for management and reintroduction aimed at favouring genetic diversity and avoiding extinction." (source : auteurs) Type de publication : périodique Référence biblio : Rascle P., Flaven E., Bioret F., Magnanon S., Glemarec E., Gallet S., Imbert E., 2019 - Genetic consequences of long-term isolation for the last French population of Eryngium viviparum (Apiaceae). Botanical Journal of the Linnean Society, 191 (8) : 285-298. ID PMB : 69172 Permalink : http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=69172
in Botanical Journal of the Linnean Society > vol. 191, n°8 (Année 2019) . - pp. 285-298[article]Exemplaires(0)
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Titre : An ecological connectivity network maintains genetic diversity of a flagship wildflower, Pulsatilla vulgaris Type de document : texte imprimé Auteurs : Michelle DiLeo (Michelle F.), Auteur ; Yessica Rico, Auteur ; Hans Juergen Boehmer, Auteur ; Helene Wagner (Helene H.), Auteur Année de publication : 2017 Article en page(s) : pp. 12-21 Langues : Anglais (eng) Catégories : [habitats/milieux] 34 - Pelouses calcicoles sèches et steppes
[Espèces (in biblio)] Pulsatilla vulgaris Mill.Mots-clés : connectivité fonctionnelle réelle réseau écologique fragmentation des habitats diversité génétique génétique du paysage microsatellite Résumé : "Ecological connectivity networks have been proposed as an efficient way to reconnect communities in fragmented landscapes. Yet few studies have evaluated if they are successful at enhancing actual functional connectivity (i.e. realized dispersal or gene flow) of focal species, or if this enhanced connectivity is enough to maintain genetic diversity and fitness of plant populations. Here we test the efficacy of an ecological connectivity network implemented in southern Germany since 1989 to reconnect calcareous grassland fragments through rotational shepherding. We genotyped 1449 individuals from 57 populations and measured fitness-related traits in 10 populations of Pulsatilla vulgaris, a flagship species of calcareous grasslands in Europe. We tested if the shepherding network explained functional connectivity in P. vulgaris and if higher connectivity translated to higher genetic diversity and fitness of populations. We found that population-specific Fst was lowest in populations that had high connectivity within the shepherding network, and that well-connected populations within the network had significantly higher genetic diversity than ungrazed and more isolated grazed populations. Moreover, genetic diversity was significantly positively correlated with both seed set and seed mass. Together our results suggest that the implementation of an ecological shepherding network is an effective management measure to maintain functional connectivity and genetic diversity at the landscape scale for a calcareous grassland specialist. Populations with reduced genetic diversity would likely benefit from inclusion, or better integration into the ecological connectivity network. Our study demonstrates the often postulated but rarely tested sequence of positive associations between connectivity, genetic diversity, and fitness at the landscape scale, and provides a framework for testing the efficacy of ecological connectivity networks for focal species using molecular genetic tools." (source : auteurs) Type de publication : périodique Référence biblio : DiLeo M., Rico Y., Boehmer H., Wagner H., 2017 - An ecological connectivity network maintains genetic diversity of a flagship wildflower, Pulsatilla vulgaris. Biological conservation, 212 : 12-21. ID PMB : 65426 DOI : 10.1016/j.biocon.2017.05.026/10.1016/j.biocon.2017.05.026 Permalink : http://www.cbnbrest.fr/catalogue_en_ligne/index.php?lvl=notice_display&id=65426
in Biological conservation > vol. 212 (Août 2017) . - pp. 12-21[article]Exemplaires(0)
Disponibilité aucun exemplaire Dynamique de la diversité génétique dans les populations naturelles et artificielles de plantes autogames / Thomas Bataillon (2003)
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