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Mitchell, Edward
Résultat de la recherche
The testate lobose amoebae (order Arcellinida Kent, 1880) finally find their home within Amoebozoa
2005, Nikolaev, Sergey I, Mitchell, Edward, Petrov, Nikolay B, Berney, Cédric, Fahrni, José, Pawlowski, Jan
Testate lobose amoebae (order Arcellinida Kent, 1880) are common in all aquatic and terrestrial habitats, yet they are one of the last higher taxa of unicellular eukaryotes that has not found its place in the tree of life. The morphological approach did not allow to ascertain the evolutionary origin of the group or to prove its monophyly. To solve these challenging problems, we analyzed partial small-subunit ribosomal RNA (SSU rRNA) genes of seven testate lobose amoebae from two out of the three suborders and seven out of the 13 families belonging to the Arcellinida. Our data support the monophyly of the order and clearly establish its position among Amoebozoa, as a sister-group to the clade comprising families Amoebidae and Hartmannellidae. Complete SSU rRNA gene sequences from two species and a partial actin sequence from one species confirm this position. Our phylogenetic analyses including representatives of all sequenced lineages of lobose amoebae suggest that a rigid test appeared only once during the evolution of the Amoebozoa, and allow reinterpretation of some morphological characters used in the systematics of Arcellinida. (c) 2005 Published by Elsevier GmbH.
Soil protistology rebooted: 30 fundamental questions to start with
, Geisen, Stefan, Mitchell, Edward, Wilkinson, David M, Adl, Sina, Bonkowski, Michael, Brown, Matthew W, Fiore-Donno, Anna Maria, Heger, Thierry, Jassey, Vincent E.J, Krashevska, Valentyna, Lahr, Daniel J.G, Marcisz, Katarzyna, Mulot, Matthieu, Payne, Richard, Singer, David, Anderson, Roger O, Charman, Dan J, Ekelund, Flemming, Griffiths, Bryan S, Rønn, Regin, Smirnov, Alexey, Bass, David, Belbahri, Lassaâd, Berney, Cédric, Blandenier, Quentin, Blandenier, Quentin, Chatzinotas, Antonis, Clarholm, Marianne, Dunthorn, Micah, Feest, Alan, Fernández, Leonardo D, Foissner, Wilhelm, Fournier, Bertrand, Gentekaki, Eleni, Hájek, Michal, Helder, Johannes, Jousset, Alexandre, Koller, Robert, Kumar, Santosh, La Terza, Antonietta, Lamentowicz, Mariusz, Mazei, Yuri, Santos, Susana S, Seppey, Christophe V.W, Spiegel, Frederick W, Walochnik, Julia, Winding, Anne, Lara, Enrique
Protists are the most diverse eukaryotes. These microbes are keystone organisms of soil ecosystems and regulate essential processes of soil fertility such as nutrient cycling and plant growth. Despite this, protists have received little scientific attention, especially compared to bacteria, fungi and nematodes in soil studies. Recent methodological advances, particularly in molecular biology techniques, have made the study of soil protists more accessible, and have created a resurgence of interest in soil protistology. This ongoing revolution now enables comprehensive investigations of the structure and functioning of soil protist communities, paving the way to a new era in soil biology. Instead of providing an exhaustive review, we provide a synthesis of research gaps that should be prioritized in future studies of soil protistology to guide this rapidly developing research area. Based on a synthesis of expert opinion we propose 30 key questions covering a broad range of topics including evolution, phylogenetics, functional ecology, macroecology, paleoecology, and methodologies. These questions highlight a diversity of topics that will establish soil protistology as a hub discipline connecting different fundamental and applied fields such as ecology, biogeography, evolution, plant-microbe interactions, agronomy, and conservation biology. We are convinced that soil protistology has the potential to be one of the most exciting frontiers in biology.
The Testate Lobose Amoebae (Order Arcellinida Kent, 1880) Finally Find their Home within Amoebozoa
2005, Nikolaev, Sergey I., Mitchell, Edward, Petrov, Nikolay B., Berney, Cédric, Fahrni, José, Pawlowski, Jan
Testate lobose amoebae (order Arcellinida Kent, 1880) are common in all aquatic and terrestrial habitats, yet they are one of the last higher taxa of unicellular eukaryotes that has not found its place in the tree of life. The morphological approach did not allow to ascertain the evolutionary origin of the group or to prove its monophyly. To solve these challenging problems, we analyzed partial small-subunit ribosomal RNA (SSU rRNA) genes of seven testate lobose amoebae from two out of the three suborders and seven out of the 13 families belonging to the Arcellinida. Our data support the monophyly of the order and clearly establish its position among Amoebozoa, as a sister-group to the clade comprising families Amoebidae and Hartmannellidae. Complete SSU rRNA gene sequences from two species and a partial actin sequence from one species confirm this position. Our phylogenetic analyses including representatives of all sequenced lineages of lobose amoebae suggest that a rigid test appeared only once during the evolution of the Amoebozoa, and allow reinterpretation of some morphological characters used in the systematics of Arcellinida.
CBOL Protist Working Group: Barcoding Eukaryotic Richness beyond the Animal, Plant, and Fungal Kingdoms
, Pawlowski, Jan, Audic, Stéphane, Adl, Sina, Bass, David, Belbahri, Lassaâd, Berney, Cédric, Bowser, Samuel S., Cepicka, Ivan, Decelle, Johan, Dunthorn, Micah, Fiore-Donno, Anna Maria, Gile, Gillian H., Holzmann, Maria, Jahn, Regine, Jirků, Miloslav, Keeling, Patrick J., Kostka, Martin, Kudryavtsev, Alexander, Lara, Enrique, Lukeš, Julius, Mann, David G., Mitchell, Edward, Nitsche, Frank, Romeralo, Maria, Saunders, Gary W., Simpson, Alastair G. B., Smirnov, Alexey V., Spouge, John L., Stern,Rowena F., Stoeck, Thorsten, Zimmermann, Jonas, Schindel, David, de Vargas, Colomban
Parasites dominate hyperdiverse soil protist communities in Neotropical rainforests
, Mahé, Frédéric, de Vargas, Colomban, Bass, David, Czech, Lucas, Stamatakis, Alexandros, Lara, Enrique, Singer, David, Mayor, Jordan, Bunge, John, Sernaker, Sarah, Siemensmeyer, Tobias, Trautmann, Isabelle, Romac, Sarah, Berney, Cédric, Kozlov, Alexey, Mitchell, Edward, Seppey, Christophe V. W, Egge, Elianne, Lentendu, Guillaume, Wirth, Rainer, Trueba, Gabriel, Dunthorn, Micah
High animal and plant richness in tropical rainforest communities has long intrigued naturalists. It is unknown if similar hyperdiversity patterns are reflected at the microbial scale with unicellular eukaryotes (protists). Here we show, using environmental metabarcoding of soil samples and a phylogeny-aware cleaning step, that protist communities in Neotropical rainforests are hyperdiverse and dominated by the parasitic Apicomplexa, which infect arthropods and other animals. These host-specific parasites potentially contribute to the high animal diversity in the forests by reducing population growth in a density-dependent manner. By contrast, too few operational taxonomic units (OTUs) of Oomycota were found to broadly drive high tropical tree diversity in a host-specific manner under the Janzen-Connell model. Extremely high OTU diversity and high heterogeneity between samples within the same forests suggest that protists, not arthropods, are the most diverse eukaryotes in tropical rainforests. Our data show that protists play a large role in tropical terrestrial ecosystems long viewed as being dominated by macroorganisms.