Consulta: creatorFacets:"Audic, Stephane"
Registros recuperados: 7
Data/hora: 09/06/2024 15:44:18

Diverse molecular signatures for ribosomally 'active' Perkinsea in marine sediments
Provedor de dados: 5
Autores: Chambouvet, Aurelie; Berney, Cedric; Romac, Sarah; Audic, Stephane; Maguire, Finlay; De Vargas, Colomban; Richards, Thomas A.
Background: Perkinsea are a parasitic lineage within the eukaryotic superphylum Alveolata. Recent studies making use of environmental small sub-unit ribosomal RNA gene (SSU rDNA) sequencing methodologies have detected a significant diversity and abundance of Perkinsea-like phylotypes in freshwater environments. In contrast only a few Perkinsea environmental sequences have been retrieved from marine samples and only two groups of Perkinsea have been cultured and morphologically described and these are parasites of marine molluscs or marine protists. These two marine groups form separate and distantly related phylogenetic clusters, composed of closely related lineages on SSU rDNA trees. Here, we test the hypothesis that Perkinsea are a hitherto under-sampled...
Tipo: Text
Palavras-chave: 454 pyrosequencing; Perkinsus; Parvilucifera; Food web; Protist; Parasite.
Ano: 2014
URL: https://archimer.ifremer.fr/doc/00374/48496/48830.pdf

Eukaryotic plankton diversity in the sunlit ocean
Provedor de dados: 5
Autores: De Vargas, Colomban; Audic, Stephane; Henry, Nicolas; Decelle, Johan; Mahe, Frederic; Logares, Ramiro; Lara, Enrique; Berney, Cedric; Le Bescot, Noan; Probert, Ian; Carmichael, Margaux; Poulain, Julie; Romac, Sarah; Colin, Sebastien; Aury, Jean-marc; Bittner, Lucie; Chaffron, Samuel; Dunthorn, Micah; Engelen, Stefan; Flegontova, Olga; Guidi, Lionel; Horak, Ales; Jaillon, Olivier; Lima-mendez, Gipsi; Lukes, Julius; Malviya, Shruti; Morard, Raphael; Mulot, Matthieu; Scalco, Eleonora; Siano, Raffaele; Vincent, Flora; Zingone, Adriana; Dimier, Celine; Picheral, Marc; Searson, Sarah; Kandels-lewis, Stefanie; Acinas, Silvia G.; Bork, Peer; Bowler, Chris; Gorsky, Gabriel; Grimsley, Nigel; Hingamp, Pascal; Iudicone, Daniele; Not, Fabrice; Ogata, Hiroyuki; Pesant, Stephane; Raes, Jeroen; Sieracki, Michael E.; Speich, Sabrina; Stemmann, Lars; Sunagawa, Shinichi; Weissenbach, Jean; Wincker, Patrick; Karsenti, Eric.
Marine plankton support global biological and geochemical processes. Surveys of their biodiversity have hitherto been geographically restricted and have not accounted for the full range of plankton size. We assessed eukaryotic diversity from 334 size-fractionated photic-zone plankton communities collected across tropical and temperate oceans during the circumglobal Tara Oceans expedition. We analyzed 18S ribosomal DNA sequences across the intermediate plankton-size spectrum from the smallest unicellular eukaryotes (protists, &gt; 0.8 micrometers) to small animals of a few millimeters. Eukaryotic ribosomal diversity saturated at similar to 150,000 operational taxonomic units, about one-third of which could not be assigned to known eukaryotic groups....
Tipo: Text
Ano: 2015
URL: http://archimer.ifremer.fr/doc/00270/38135/37217.pdf

Patterns of Rare and Abundant Marine Microbial Eukaryotes
Provedor de dados: 5
Autores: Logares, Ramiro; Audic, Stephane; Bass, David; Bittner, Lucie; Boutte, Christophe; Christen, Richard; Claverie, Jean-michel; Decelle, Johan; Dolan, John R.; Dunthorn, Micah; Edvardsen, Bente; Gobet, Angelique; Kooistra, Wiebe H. C. F.; Mahe, Frederic; Not, Fabrice; Ogata, Hiroyuki; Pawlowski, Jan; Pernice, Massimo C.; Romac, Sarah; Shalchian-tabrizi, Kamran; Simon, Nathalie; Stoeck, Thorsten; Santini, Sebastien; Siano, Raffaele; Wincker, Patrick; Zingone, Adriana; Richards, Thomas A.; De Vargas, Colomban; Massana, Ramon.
Background  Biological communities are normally composed of a few abundant and many rare species. This pattern is particularly prominent in microbial communities, in which most constituent taxa are usually extremely rare. Although abundant and rare subcommunities may present intrinsic characteristics that could be crucial for understanding community dynamics and ecosystem functioning, microbiologists normally do not differentiate between them. Here, we investigate abundant and rare subcommunities of marine microbial eukaryotes, a crucial group of organisms that remains among the least-explored biodiversity components of the biosphere. We surveyed surface waters of six separate coastal locations in Europe, independently considering the picoplankton,...
Tipo: Text
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00186/29683/28098.pdf

Benthic protists: the under-charted majority
Provedor de dados: 5
Autores: Forster, Dominik; Dunthorn, Micah; Mahe, Frederic; Dolan, John R.; Audic, Stephane; Bass, David; Bittner, Lucie; Boutte, Christophe; Christen, Richard; Claverie, Jean-michel; Decelle, Johan; Edvardsen, Bente; Egge, Elianne; Eikrem, Wenche; Gobet, Angelique; Kooistra, Wiebe H. C. F.; Logares, Ramiro; Massana, Ramon; Montresor, Marina; Not, Fabrice; Ogata, Hiroyuki; Pawlowski, Jan; Pernice, Massimo C.; Romac, Sarah; Shalchian-tabrizi, Kamran; Simon, Nathalie; Richards, Thomas A.; Santini, Sebastien; Sarno, Diana; Siano, Raffaele; Vaulot, Daniel; Wincker, Patrick; Zingone, Adriana; De Vargas, Colomban; Stoeck, Thorsten.
Marine protist diversity inventories have largely focused on planktonic environments, while benthic protists have received relatively little attention. We therefore hypothesize that current diversity surveys have only skimmed the surface of protist diversity in marine sediments, which may harbour greater diversity than planktonic environments. We tested this by analyzing sequences of the hypervariable V4 18S rRNA from benthic and planktonic protist communities sampled in European coastal regions. Despite a similar number of OTUs in both realms, richness estimations indicated that we recovered at least 70% of the diversity in planktonic protist communities, but only 33% in benthic communities. There was also little overlap of OTUs between planktonic and...
Tipo: Text
Palavras-chave: Benthic microbial communities; Coastal environments; Protist diversity; High-throughput sequencing.
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00341/45233/44658.pdf

Diversity patterns and activity of uncultured marine heterotrophic flagellates unveiled with pyrosequencing
Provedor de dados: 5
Autores: Logares, Ramiro; Audic, Stephane; Santini, Sebastien; Pernice, Massimo C.; De Vargas, Colomban; Massana, Ramon.
Flagellated heterotrophic microeukaryotes have key roles for the functioning of marine ecosystems as they channel large amounts of organic carbon to the upper trophic levels and control the population sizes of bacteria and archaea. Still, we know very little on the diversity patterns of most groups constituting this evolutionary heterogeneous assemblage. Here, we investigate 11 groups of uncultured flagellates known as MArine STramenopiles (MASTs). MASTs are ecologically very important and branch at the base of stramenopiles. We explored the diversity patterns of MASTs using pyrosequencing (18S rDNA) in coastal European waters. We found that MAST groups range from highly to lowly diversified. Pyrosequencing (hereafter '454') allowed us to approach to the...
Tipo: Text
Palavras-chave: Diversity; Heterotrophic-flagellates; MAST; Pyrosequencing; Stramenopiles.
Ano: 2012
URL: https://archimer.ifremer.fr/doc/00374/48501/48815.pdf

Marine protist diversity in European coastal waters and sediments as revealed by high-throughput sequencing
Provedor de dados: 5
Autores: Massana, Ramon; Gobet, Angelique; Audic, Stephane; Bass, David; Bittner, Lucie; Boutte, Christophe; Chambouvet, Aurelie; Christen, Richard; Claverie, Jean-michel; Decelle, Johan; Dolan, John R.; Dunthorn, Micah; Edvardsen, Bente; Forn, Irene; Forster, Dominik; Guillou, Laure; Jaillon, Olivier; Kooistra, Wiebe H. C. F.; Logares, Ramiro; Mahe, Frederic; Not, Fabrice; Ogata, Hiroyuki; Pawlowski, Jan; Pernice, Massimo C.; Probert, Ian; Romac, Sarah; Richards, Thomas; Santini, Sebastien; Shalchian-tabrizi, Kamran; Siano, Raffaele; Simon, Nathalie; Stoeck, Thorsten; Vaulot, Daniel; Zingone, Adriana; De Vargas, Colomban.
Although protists are critical components of marine ecosystems, they are still poorly characterized. Here we analysed the taxonomic diversity of planktonic and benthic protist communities collected in six distant European coastal sites. Environmental deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) from three size fractions (pico-, nano- and micro/mesoplankton), as well as from dissolved DNA and surface sediments were used as templates for tag pyrosequencing of the V4 region of the 18S ribosomal DNA. Beta-diversity analyses split the protist community structure into three main clusters: picoplankton-nanoplankton-dissolved DNA, micro/mesoplankton and sediments. Within each cluster, protist communities from the same site and time clustered together,...
Tipo: Text
Ano: 2015
URL: http://archimer.ifremer.fr/doc/00275/38594/37190.pdf

Assessment of Species Diversity and Distribution of an Ancient Diatom Lineage Using a DNA Metabarcoding Approach
Provedor de dados: 5
Autores: Nanjappa, Deepak; Audic, Stephane; Romac, Sarah; Kooistra, Wiebe H. C. F.; Zingone, Adriana.
Background: Continuous efforts to estimate actual diversity and to trace the species distribution and ranges in the natural environments have gone in equal pace with advancements of the technologies in the study of microbial species diversity from microscopic observations to DNA-based barcoding. DNA metabarcoding based on Next Generation Sequencing (NGS) constitutes the latest advancement in these efforts. Here we use NGS data from different sites to investigate the geographic range of six species of the diatom family Leptocylindraceae and to identify possible new taxa within the family. Methodology/Principal Findings: We analysed the V4 and V9 regions of the nuclear-encoded SSU rDNA gene region in the NGS database of the European ERA-Biodiversa project...
Tipo: Text
Ano: 2014
URL: https://archimer.ifremer.fr/doc/00374/48494/48846.pdf