|
|
|
| Registros recuperados: 43 | |
|
|
| Stern, Rowena; Kraberg, Alexandra; Bresnan, Eileen; Kooistra, Wiebe H. C. F.; Lovejoy, Connie; Montresor, Marina; Moran, Xose Anxelu G.; Not, Fabrice; Salas, Rafael; Siano, Raffaele; Vaulot, Daniel; Amaral-zettler, Linda; Zingone, Adriana; Metfies, Katja. |
| Protists (microbial eukaryotes) are diverse, major components of marine ecosystems, and are fundamental to ecosystem services. In the last 10 years, molecular studies have highlighted substantial novel diversity in marine systems including sequences with no taxonomic context. At the same time, many known protists remain without a DNA identity. Since the majority of pelagic protists are too small to identify by light microscopy, most are neither comprehensively or regularly taken into account, particularly in Long-term Ecological Research Sites. This potentially undermines the quality of research and the accuracy of predictions about biological species shifts in a changing environment. The ICES Working Group for Phytoplankton and Microbial Ecology conducted... |
| Tipo: Text |
Palavras-chave: Protists; Long-term Ecological Research Station; Molecular; Time-series; Questionnaire; Literature survey. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00455/56708/58470.pdf |
| |
|
|
| Nezan, Elisabeth; Siano, Raffaele; Boulben, Sylviane; Six, Christophe; Bilien, Gwenael; Cheze, Karine; Duval, Audrey; Le Panse, Sophie; Quere, Julien; Chomerat, Nicolas. |
| The family Kareniaceae is mostly known in France for recurrent blooms of Karenia mikimotoi in the Atlantic, English Channel, and Mediterranean Sea and for the unusual green discoloration in the saltwater lagoon of Diana (Corsica) caused by Karlodinium corsicum in April 1994. In terms of diversity, this taxonomic group was long overlooked owing to the difficult identification of these small unarmored dinoflagellates. In this study, thanks to the molecular characterization performed on single cells from field samples and cultures, twelve taxonomic units were assigned to the known genera Karenia, Karlodinium and Takayama, whereas one could not be affiliated to any described genus. The molecular phylogeny inferred from the D1–D2 region of the LSU rDNA showed... |
| Tipo: Text |
Palavras-chave: Genetic diversity; Haemolytic; Kareniaceae; Pigments; Single cell; Taxonomy. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00225/33611/32310.pdf |
| |
|
| |
|
|
| Chapelle, Annie; Le Bec, Claude; Siano, Raffaele; Caradec, Florian; Andrieux, Francoise. |
| Suite à l’efflorescence de grande ampleur d’Alexandrium minutum et des événements toxiques associés en Rade de Brest en 2012, un projet a été monté avec la Région dans le cadre du développement du port de Brest, pour élucider les contrôles de cette efflorescence. De juillet à août 2013, l’Ifremer a organisé un échantillonnage serré dans l’estuaire de Daoulas, zone la plus touchée en 2012 (rapport d’avancement n°1). Une autre partie de ce projet vise à la détection (rapport d’avancement n°2) et à la quantification (rapport d’avancement n°3) des traces biologiques d’A. minutum dans les sédiments de surface en différentes stations de la Rade de Brest présentant des caractéristiques sédimentaires différentes. Pour la détection des traces biologiques (ADN... |
| Tipo: Text |
|
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00191/30231/28647.pdf |
| |
|
|
| Roux, Pauline; Siano, Raffaele; Collin, Karine; Bilien, Gwenael; Sinquin, Corinne; Marchand, Laetitia; Zykwinska, Agata; Delbarre-ladrat, Christine; Schapira, Mathilde. |
| High biomasses of the marine dinoflagellate Lepidodinium chlorophorum cause green seawater discolorations along Southern Brittany (NE Atlantic, France). The viscosity associated to these phenomena has been related to problems in oyster cultivation. The harmful effect of L. chlorophorum might originate from the secretion of Extracellular Polymeric Substances (EPS). To understand whether the EPS are produced by L. chlorophorum or its associated bacteria, or if they are a product of their interaction, batch cultures were performed under non-axenic and pseudo-axenic conditions for three strains. Maximum dinoflagellate cell abundances were observed in pseudo-axenic cultures. The non-sinking fraction of polymers (Soluble Extracellular Polymers, SEP), mainly... |
| Tipo: Text |
|
| Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00682/79403/81948.pdf |
| |
|
|
| Girault, Mathias; Siano, Raffaele; Labry, Claire; Latimier, Marie; Jauzein, Cecile; Beneyton, Thomas; Buisson, Lionel; Del Amo, Yolanda; Baret, Jean-christophe. |
| Adaptation of cell populations to environmental changes is mediated by phenotypic variability at the single-cell level. Enzyme activity is a key factor in cell phenotype and the expression of the alkaline phosphatase activity (APA) is a fundamental phytoplankton strategy for maintaining growth under phosphate-limited conditions. Our aim was to compare the APA among cells and species revived from sediments of the Bay of Brest (Brittany, France), corresponding to a pre-eutrophication period (1940’s) and a beginning of a post-eutrophication period (1990’s) during which phosphate concentrations have undergone substantial variations. Both toxic marine dinoflagellate Alexandrium minutum and the non-toxic dinoflagellate Scrippsiella acuminata were revived from... |
| Tipo: Text |
Palavras-chave: Climate-change ecology; Microbial ecology. |
| Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00679/79097/81568.pdf |
| |
|
|
| Percopo, Isabella; Siano, Raffaele; Rossi, Rachele; Soprano, Vittorio; Sarno, Diana; Zingone, Adriana. |
| A new photosynthetic planktonic marine dinoflagellate, Azadinium dexteroporum sp. nov., is described from the Gulf of Naples (South Tyrrhenian Sea, Mediterranean Sea). The plate formula of the species, Po, cp, X, 4, 3a, 6, 6C, 5?S, 6'" and 2, is typical for this recently described genus. Azadinium dexteroporum is the smallest rep-resentative of the genus (8.5m average length, 6.2m average width) and shares the presence of a small antapical spine with the type species A.spinosum and with A.polongum. However, it differs from all other Azadinium species for the markedly asymmetrical Po plate and the position of the ventral pore, which is located at the right posterior end of the Po plate. Another peculiarity of A.dexteroporum is the pronounced concavity of... |
| Tipo: Text |
Palavras-chave: Azadinium; Azaspiracid; Dinoflagellate; LC; MS-TOF; LTER-MC; Mediterranean Sea; Phylogeny; Taxonomy. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00171/28199/27278.pdf |
| |
|
| |
|
| |
|
|
| Penaud, Aurelie; Hardy, William; Lambert, Clement; Marret, Fabienne; Masure, Edwige; Seryais, Thomas; Siano, Raffaele; Wary, Melanie; Mertens, Kenneth. |
| Dinoflagellates are part of the marine plankton and about 200 species produce a cyst (dinocyst) during their life cycle, these organic-walled sexually-produced cysts being fossilizable in sediments for hundreds of millions of years. Over the past 40–50 years, dinocysts have led to major advances on Mesozoic-Cenozoic research, in terms of biostratigraphy and paleogeogeography. Dinocyst taxonomy has then been continuously revised, with the tabulation being the main morphological link between living dinoflagellates and fossilized cysts. Over the Quaternary, and based on the principle of uniformitarianism (i.e. species ecology did not change through time), relationships between modern assemblages and present-day environmental factors controlling their... |
| Tipo: Text |
Palavras-chave: Dinoflagellate; Cyst-motile stage relationship; Modern dinocyst distribution; Paleoecology; Biostratigraphy; Ancient DNA. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00463/57476/59749.pdf |
| |
|
|
| Lemonnier, Hugues; Royer, Florence; Lopez, Etienne; Berne, Stéphanie; Boher, Laura; Coignot, Elise; Desnues, Anne; Dupouy, Cécile; Helly, Maëlle; Gérard, Philippe; Gunkel-grillon, Peggy; Jamet, Léocadie; Lemestre, Monica; Liufau, Félise; Siano, Raffaele; Soulard, Benoit. |
| De par des mutations économiques, démographiques et sociétales, que connaît à ce jour la Nouvelle-Calédonie, des pressions anthropiques ne cessent de croître sur les milieux littoraux et côtiers. Les rivières sont d’importants vecteurs de transport de sédiments et d’éléments dissous. Ces apports, s’ils sont essentiels pour le fonctionnement des écosystèmes côtiers, peuvent être néfastes en cas d’excès (sels nutritifs, métaux et autres contaminants). Le projet SEARSE a pour objectifs de qualifier et de quantifier les apports des rivières et suivre leur devenir dans les panaches dans le lagon autour du grand Nouméa. |
| Tipo: Text |
|
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00630/74207/73835.pdf |
| |
|
|
| Ramond, Pierre; Sourisseau, Marc; Simon, Nathalie; Romac, Sarah; Schmitt, Sophie; Rigaut-jalabert, Fabienne; Henry, Nicolas; De Vargas, Colomban; Siano, Raffaele. |
| The study of protistan functional diversity is crucial to understand the dynamics of oceanic ecological processes. We combined the metabarcoding data of various coastal ecosystems and a newly developed trait‐based approach to study the link between taxonomic and functional diversity across marine protistan communities of different size‐classes. Environmental DNA was extracted and the V4 18S rDNA genomic region was amplified and sequenced. In parallel, we tried to annotate the Operational Taxonomic Units (OTUs) from our metabarcoding dataset to 30 biological traits using published and accessible information on protists. We then developed a method to study trait correlations across protists (i.e. trade‐offs) in order to build the best functional groups.... |
| Tipo: Text |
|
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00478/58964/61554.pdf |
| |
|
| |
|
|
| Delebecq, Gaspard; Schmidt, Sabine; Ehrhold, Axel; Latimier, Marie; Siano, Raffaele. |
| The biological processes involved in the preservation, viability, and revival of long‐term dormant dinoflagellate cysts buried in sediments remain unknown. Based on studies of plant seed physiology, we tested whether the revival of ancient cysts preserved in century‐old sediments from the Bay of Brest (France) could be stimulated by melatonin and gibberellic acid, two molecules commonly used in seed priming. Dinoflagellates were revived from sediments dated to approximately 150 years ago (156 ± 27, 32 cm depth), extending the known record age of cyst viability previously established as around one century. A culture suspension of sediments mixed with melatonin and gibberellic acid solutions as biostimulants exhibited germination of 11 dinoflagellate taxa... |
| Tipo: Text |
Palavras-chave: Alexandrium; Cyst; Dinoflagellate; Gibberellic acid; Melatonin; Paleoecology; Priming; Scrippsiella; Resurrection ecology. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00627/73960/73321.pdf |
| |
|
|
| 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, > 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 |
| |
|
|
| Mondeguer, Florence; Souard, Florence; Guitton, Yann; Latimier, Marie; Quere, Julien; Sibat, Manoella; Hess, Philipp; Siano, Raffaele. |
| Aquatic ecosystems worldwide have been negatively affected by eutrophication, many of them driven by increasing nutrient inputs from untreated domestic sewage and industrial and agricultural wastewater. During their life cycle, Alexandrium minutum and Scrippsiella donghaienis can produce resistant and revivable cysts that can accumulate in the sediments of the coastal marine environment for hundreds of years. As a working hypothesis, we presumed that these two genera have preserved their adaptation to such ecosystem changes in the form of cysts in the old sediments. From revivified cysts, some cultures of toxic and non-toxic dinoflagellates (A. minutum and S. donghaienis) were analyzed by a untargeted metabolomics approach by LC-HRMS to study the possible... |
| Tipo: Text |
|
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00440/55199/56664.pdf |
| |
|
| |
|
|
| Ramond, Pierre; Siano, Raffaele; Schmitt, Sophie; De Vargas, Colomban; Marié, Louis; Memery, Laurent; Sourisseau, Marc. |
| Oceanic physics at fine scale; e.g. eddies, fronts, filaments; are notoriously difficult to sample. However, an increasing number of theoretical approaches hypothesize that these processes affect phytoplankton diversity which have cascading effects on regional ecosystems. In 2015, we targeted the Iroise Sea (France) and evidenced the setting up of the Ushant tidal front from the beginning of spring to late summer. Seawater samples were taken during three sampling cruises and DNA-barcoding allowed us to investigate patterns of eukaryotic phytoplankton diversity across this front. First focusing on patterns of taxonomic richness, we evidenced that the front harbored a hotspot of eukaryotic phytoplankton diversity sustained throughout summer. We then detail... |
| Tipo: Text |
|
| Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00677/78933/81307.pdf |
| |
|
|
| 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 |
| |
|
|
| Guillou, Laure; Bachar, Dipankar; Audic, S; Bass, David; Berney, Cedric; Bittner, Lucie; Boutte, Christophe; Burgaud, Gaetan; De Vargas, Colomban; Decelle, Johan; Del Campo, Javier; Dolan, John R.; Dunthorn, Micah; Edvardsen, Bente; Holzmann, Maria; Kooistra, Wiebe H. C. F.; Lara, Enrique; Le Bescot, Noan; Logares, Ramiro; Mahe, F; Massana, Ramon; Montresor, Marina; Morard, Raphael; Not, Fabrice; Pawlowski, Jan; Probert, Ian; Sauvadet, Anne-laure; Siano, Raffaele; Stoeck, Thorsten; Vaulot, Daniel; Zimmermann, Pascal; Christen, Richard. |
| The interrogation of genetic markers in environmental meta-barcoding studies is currently seriously hindered by the lack of taxonomically curated reference data sets for the targeted genes. The Protist Ribosomal Reference database (PR2, http://ssurrna. org/) provides a unique access to eukaryotic small sub-unit (SSU) ribosomal RNA and DNA sequences, with curated taxonomy. The database mainly consists of nuclear-encoded protistan sequences. However, metazoans, land plants, macrosporic fungi and eukaryotic organelles (mitochondrion, plastid and others) are also included because they are useful for the analysis of hightroughput sequencing data sets. Introns and putative chimeric sequences have been also carefully checked. Taxonomic assignation of sequences... |
| Tipo: Text |
|
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00114/22492/20174.pdf |
| |
| Registros recuperados: 43 | |
|
|
|
