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| 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.... |
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| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00270/38135/37217.pdf |
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| Weiner, Agnes K. M.; Morard, Raphael; Weinkauf, Manuel F. G.; Darling, Kate F.; André, Aurore; Quillévéré, Frédéric; Ujiie, Yurika; Douady, Christophe J.; De Vargas, Colomban; Kucera, Michal. |
| Single-cell genetic analysis is an essential method to investigate the biodiversity and evolutionary ecology of marine protists. In protist groups that do not reproduce under laboratory conditions, this approach provides the only means to directly associate molecular sequences with cell morphology. The resulting unambiguous taxonomic identification of the DNA sequences is a prerequisite for barcoding and analyses of environmental metagenomic data. Extensive single-cell genetic studies have been carried out on planktonic foraminifera over the past 20 years to elucidate their phylogeny, cryptic diversity, biogeography, and the relationship between genetic and morphological variability. In the course of these investigations, it has become evident that genetic... |
| Tipo: Text |
Palavras-chave: Foraminifera; Protists; Single-cell genetics; Cryptic diversity; Comparability; Methods; Laboratory protocols; Standardization. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00383/49460/49938.pdf |
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| Morard, Raphael; Escarguel, Gilles; Weiner, Agnes K. M.; Andre, Aurore; Douady, Christophe J.; Wade, Christopher M.; Darling, Kate F.; Ujiie, Yurika; Seears, Heidi A.; Quillevere, Frederic; De Garidel-thoron, Thibault; De Vargas, Colomban; Kucera, Michal. |
| Investigations of biodiversity, biogeography, and ecological processes rely on the identification of "species" as biologically significant, natural units of evolution. In this context, morphotaxonomy only provides an adequate level of resolution if reproductive isolation matches morphological divergence. In many groups of organisms, morphologically defined species often disguise considerable genetic diversity, which may be indicative of the existence of cryptic species. The diversity hidden by morphological species can be disentangled through genetic surveys, which also provide access to data on the ecological distribution of genetically circumscribed units. These units can be identified by unique DNA sequence motifs and allow studies of evolutionary and... |
| Tipo: Text |
Palavras-chave: Cryptic species; Genetic diversity; Planktonic foraminifera; Molecular nomenclature; MOTUs. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00383/49408/49900.pdf |
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| Andre, Aurore; Quillevere, Frederic; Morard, Raphael; Ujiie, Yurika; Escarguel, Gilles; De Vargas, Colomban; De Garidel-thoron, Thibault; Douady, Christophe J.. |
| The use of planktonic foraminifera in paleoceanography requires taxonomic consistency and precise assessment of the species biogeography. Yet, ribosomal small subunit (SSUr) DNA analyses have revealed that most of the modern morphospecies of planktonic foraminifera are composed of a complex of several distinct genetic types that may correspond to cryptic or pseudo-cryptic species. These genetic types are usually delimitated using partial sequences located at the 3'end of the SSUrDNA, but typically based on empirical delimitation. Here, we first use patristic genetic distances calculated within and among genetic types of the most common morpho-species to show that intra-type and inter-type genetic distances within morpho-species may significantly overlap,... |
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| Ano: 2014 |
URL: https://archimer.ifremer.fr/doc/00290/40107/38859.pdf |
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| 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 |
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| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00114/22492/20174.pdf |
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| Morard, Raphael; Quillevere, Frederic; Douady, Christophe J.; De Vargas, Colomban; De Garidel-thoron, Thibault; Escarguel, Gilles. |
| The planktonic foraminiferal morpho-species Globoconella inflata is widely used as a stratigraphic and paleoceanographic index. While G. inflata was until now regarded as a single species, we show that it rather constitutes a complex of two pseudo-cryptic species. Our study is based on SSU and ITS rDNA sequence analyses and genotyping of 497 individuals collected at 49 oceanic stations covering the worldwide range of the morpho-species. Phylogenetic analyses unveil the presence of two divergent genotypes. Type I inhabits transitional and subtropical waters of both hemispheres, while Type II is restricted to the Antarctic subpolar waters. The two genetic species exhibit a strictly allopatric distribution on each side of the Antarctic Subpolar Front. On the... |
| Tipo: Text |
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| Ano: 2011 |
URL: https://archimer.ifremer.fr/doc/00144/25559/23704.pdf |
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