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1. Community-Level Responses to Iron Availability in Open Ocean Plankton Ecosystems

Author

Caputi, L, Carradec, Q, Eveillard, D, Kirilovsky, A, Pelletier, E, Pierella Karlusich, JJ, Rocha Jimenez Vieira, F, Villar, E, Chaffron, S, Malviya, S, Scalco, E, Acinas, SG, Alberti, A, Aury, JM, Benoiston, AS, Bertrand, A, Biard, T, Bittner, L, Boccara, M, Brum, JR, Brunet, C, Busseni, G, Carratalà, A, Claustre, H, Coelho, LP, Colin, S, D'Aniello, S, Da Silva, C, Del Core, M, Doré, H, Gasparini, S, Kokoszka, F, Jamet, JL, Lejeusne, C, Lepoivre, C, Lescot, M, Lima-Mendez, G, Lombard, F, Lukeš, J, Maillet, N, Madoui, MA, Martinez, E, Mazzocchi, MG, Néou, MB, Paz-Yepes, J, Poulain, J, Ramondenc, S, Romagnan, JB, Roux, S, Salvagio Manta, D, Sanges, R, Speich, S, Sprovieri, M, Sunagawa, S, Taillandier, V, Tanaka, A, Tirichine, L, Trottier, C, Uitz, J, Veluchamy, A, Veselá, J, Vincent, F, Yau, S, Kandels-Lewis, S, Searson, S, Dimier, C, Picheral, M, Bork, P, Boss, E, de Vargas, C, Follows, MJ, Grimsley, N, Guidi, L, Hingamp, P, Karsenti, E, Sordino, P, Stemmann, L, Sullivan, MB, Tagliabue, A, Zingone, A, Garczarek, L, d'Ortenzio, F, Testor, P, Not, F, d'Alcalà, MR, Wincker, P, Bowler, C, and Iudicone, D

Subjects
Genetics, Atmospheric Sciences, Geochemistry, Meteorology & Atmospheric Sciences, Oceanography
Abstract

Predicting responses of plankton to variations in essential nutrients is hampered by limited in situ measurements, a poor understanding of community composition, and the lack of reference gene catalogs for key taxa. Iron is a key driver of plankton dynamics and, therefore, of global biogeochemical cycles and climate. To assess the impact of iron availability on plankton communities, we explored the comprehensive bio-oceanographic and bio-omics data sets from Tara Oceans in the context of the iron products from two state-of-the-art global scale biogeochemical models. We obtained novel information about adaptation and acclimation toward iron in a range of phytoplankton, including picocyanobacteria and diatoms, and identified whole subcommunities covarying with iron. Many of the observed global patterns were recapitulated in the Marquesas archipelago, where frequent plankton blooms are believed to be caused by natural iron fertilization, although they are not captured in large-scale biogeochemical models. This work provides a proof of concept that integrative analyses, spanning from genes to ecosystems and viruses to zooplankton, can disentangle the complexity of plankton communities and can lead to more accurate formulations of resource bioavailability in biogeochemical models, thus improving our understanding of plankton resilience in a changing environment.

Published
2019

3. TPX2, A novel xenopus MAP involved in spindle pole organization.

Author

Wittmann, T, Wilm, M, Karsenti, E, and Vernos, I

Subjects
Ovum, Microtubules, Animals, Xenopus, Kinesin, Xenopus Proteins, Cell Cycle Proteins, Microtubule-Associated Proteins, Neoplasm Proteins, Nuclear Proteins, Phosphoproteins, Cloning, Molecular, Mitosis, Binding Sites, Amino Acid Sequence, Molecular Sequence Data, Dyneins, Spindle Apparatus, Dynactin Complex, Cloning, Molecular, Developmental Biology, Biological Sciences, Medical and Health Sciences
Abstract

TPX2, the targeting protein for Xenopus kinesin-like protein 2 (Xklp2), was identified as a microtubule-associated protein that mediates the binding of the COOH-terminal domain of Xklp2 to microtubules (Wittmann, T., H. Boleti, C. Antony, E. Karsenti, and I. Vernos. 1998. J. Cell Biol. 143:673-685). Here, we report the cloning and functional characterization of Xenopus TPX2. TPX2 is a novel, basic 82.4-kD protein that is phosphorylated during mitosis in a microtubule-dependent way. TPX2 is nuclear during interphase and becomes localized to spindle poles in mitosis. Spindle pole localization of TPX2 requires the activity of the dynein-dynactin complex. In late anaphase TPX2 becomes relocalized from the spindle poles to the midbody. TPX2 is highly homologous to a human protein of unknown function and thus defines a new family of vertebrate spindle pole components. We investigated the function of TPX2 using spindle assembly in Xenopus egg extracts. Immunodepletion of TPX2 from mitotic egg extracts resulted in bipolar structures with disintegrating poles and a decreased microtubule density. Addition of an excess of TPX2 to spindle assembly reactions gave rise to monopolar structures with abnormally enlarged poles. We conclude that, in addition to its function in targeting Xklp2 to microtubule minus ends during mitosis, TPX2 also participates in the organization of spindle poles.

Published
2000

4. Localization of the kinesin-like protein Xklp2 to spindle poles requires a leucine zipper, a microtubule-associated protein, and dynein.

Author

Wittmann, T, Boleti, H, Antony, C, Karsenti, E, and Vernos, I

Subjects
Oocytes, Microtubules, Animals, Xenopus, Rabbits, Humans, Kinesin, Xenopus Proteins, Cell Cycle Proteins, Microtubule-Associated Proteins, Recombinant Fusion Proteins, Cell Extracts, Cell Cycle, Binding Sites, Leucine Zippers, Dimerization, Dyneins, Spindle Apparatus, Dynactin Complex, Developmental Biology, Biological Sciences, Medical and Health Sciences
Abstract

Xklp2 is a plus end-directed Xenopus kinesin-like protein localized at spindle poles and required for centrosome separation during spindle assembly in Xenopus egg extracts. A glutathione-S-transferase fusion protein containing the COOH-terminal domain of Xklp2 (GST-Xklp2-Tail) was previously found to localize to spindle poles (Boleti, H., E. Karsenti, and I. Vernos. 1996. Cell. 84:49-59). Now, we have examined the mechanism of localization of GST-Xklp2-Tail. Immunofluorescence and electron microscopy showed that Xklp2 and GST-Xklp2-Tail localize specifically to the minus ends of spindle pole and aster microtubules in mitotic, but not in interphase, Xenopus egg extracts. We found that dimerization and a COOH-terminal leucine zipper are required for this localization: a single point mutation in the leucine zipper prevented targeting. The mechanism of localization is complex and two additional factors in mitotic egg extracts are required for the targeting of GST-Xklp2-Tail to microtubule minus ends: (a) a novel 100-kD microtubule-associated protein that we named TPX2 (Targeting protein for Xklp2) that mediates the binding of GST-Xklp2-Tail to microtubules and (b) the dynein-dynactin complex that is required for the accumulation of GST-Xklp2-Tail at microtubule minus ends. We propose two molecular mechanisms that could account for the localization of Xklp2 to microtubule minus ends.

Published
1998

5. Spindle assembly in Xenopus egg extracts: respective roles of centrosomes and microtubule self-organization.

Author

HEALD, Rebecca, Tournebize, R, Habermann, A, Karsenti, E, and Hyman, A

Subjects
Animals, Cell Extracts, Centrosome, DNA, Dimethyl Sulfoxide, Dyneins, Microscopy, Fluorescence, Microtubules, Movement, Ovum, Spindle Apparatus, Tubulin, Xenopus
Abstract

In Xenopus egg extracts, spindles assembled around sperm nuclei contain a centrosome at each pole, while those assembled around chromatin beads do not. Poles can also form in the absence of chromatin, after addition of a microtubule stabilizing agent to extracts. Using this system, we have asked (a) how are spindle poles formed, and (b) how does the nucleation and organization of microtubules by centrosomes influence spindle assembly? We have found that poles are morphologically similar regardless of their origin. In all cases, microtubule organization into poles requires minus end-directed translocation of microtubules by cytoplasmic dynein, which tethers centrosomes to spindle poles. However, in the absence of pole formation, microtubules are still sorted into an antiparallel array around mitotic chromatin. Therefore, other activities in addition to dynein must contribute to the polarized orientation of microtubules in spindles. When centrosomes are present, they provide dominant sites for pole formation. Thus, in Xenopus egg extracts, centrosomes are not necessarily required for spindle assembly but can regulate the organization of microtubules into a bipolar array.

Published
1997

6. Environmental characteristics of Agulhas rings affect interocean plankton transport

Author

Tara Oceans Coordinators, Villar, E., Farrant, G. K., Follows, M., Garczarek, L., Speich, S., Audic, S., Bittner, L., Blanke, B., Brum, J. R., Brunet, C., Casotti, R., Chase, A., Dolan, J. R., d'Ortenzio, F., Gattuso, J.-P., Grima, N., Guidi, L., Hill, C. N., Jahn, O., Jamet, J.-L., Le Goff, H., Lepoivre, C., Malviya, S., Pelletier, E., Romagnan, J.-B., Roux, S., Santini, S., Scalco, E., Schwenck, S. M., Tanaka, A., Testor, P., Vannier, T., Vincent, F., Zingone, A., Dimier, C., Picheral, M., Searson, S., Kandels-Lewis, S., Acinas, S. G., Bork, P., Boss, E., de Vargas, C., Gorsky, G., Ogata, H., Pesant, S., Sullivan, M. B., Sunagawa, S., Wincker, P., Karsenti, E., Bowler, C., Not, F., Hingamp, P., and Iudicone, D.

Published
2015

7. Determinants of community structure in the global plankton interactome

Author

Tara Oceans Coordinators, Lima-Mendez, G., Faust, K., Henry, N., Decelle, J., Colin, S., Carcillo, F., Chaffron, S., Ignacio-Espinosa, J. C., Roux, S., Vincent, F., Bittner, L., Darzi, Y., Wang, J., Audic, S., Berline, L., Bontempi, G., Cabello, A. M., Coppola, L., Cornejo-Castillo, F. M., d'Ovidio, F., De Meester, L., Ferrera, I., Garet-Delmas, M.-J., Guidi, L., Lara, E., Pesant, S., Royo-Llonch, M., Salazar, G., Sànchez, P., Sebastian, M., Souffreau, C., Dimier, C., Picheral, M., Searson, S., Kandels-Lewis, S., Gorsky, G., Not, F., Ogata, H., Speich, S., Stemmann, L., Weissenbach, J., Wincker, P., Acinas, S. G., Sunagawa, S., Bork, P., Sullivan, M. B., Karsenti, E., Bowler, C., de Vargas, C., and Raes, J.

Published
2015

8. Structure and function of the global ocean microbiome

Author

Tara Oceans Coordinators, Sunagawa, S., Coelho, L. P., Chaffron, S., Kultima, J. R., Labadie, K., Salazar, G., Djahanschiri, B., Zeller, G., Mende, D. R., Alberti, A., Cornejo-Castillo, F. M., Costea, P. I., Cruaud, C., d'Ovidio, F., Engelen, S., Ferrera, I., Gasol, J. M., Guidi, L., Hildebrand, F., Kokoszka, F., Lepoivre, C., Lima-Mendez, G., Poulain, J., Poulos, B. T., Royo-Llonch, M., Sarmento, H., Vieira-Silva, S., Dimier, C., Picheral, M., Searson, S., Kandels-Lewis, S., Bowler, C., de Vargas, C., Gorsky, G., Grimsley, N., Hingamp, P., Iudicone, D., Jaillon, O., Not, F., Ogata, H., Pesant, S., Speich, S., Stemmann, L., Sullivan, M. B., Weissenbach, J., Wincker, P., Karsenti, E., Raes, J., Acinas, S. G., and Bork, P.

Published
2015

9. Eukaryotic plankton diversity in the sunlit ocean

Author

Tara Oceans Coordinators, de Vargas, C., Audic, S., Henry, N., Decelle, J., Mahé, F., Logares, R., Lara, E., Berney, C., Le Bescot, N., Probert, I., Carmichael, M., Poulain, J., Romac, S., Colin, S., Aury, J.-M., Bittner, L., Chaffron, S., Dunthorn, M., Engelen, S., Flegontova, O., Guidi, L., Horák, A., Jaillon, O., Lima-Mendez, G., Lukeš, J., Malviya, S., Morard, R., Mulot, M., Scalco, E., Siano, R., Vincent, F., Zingone, A., Dimier, C., Picheral, M., Searson, S., Kandels-Lewis, S., Acinas, S. G., Bork, P., Bowler, C., Gorsky, G., Grimsley, N., Hingamp, P., Iudicone, D., Not, F., Ogata, H., Pesant, S., Raes, J., Sieracki, M. E., Speich, S., Stemmann, L., Sunagawa, S., Weissenbach, J., Wincker, P., and Karsenti, E.

Published
2015

11. Patterns and ecological drivers of ocean viral communities

Author

Tara Oceans Coordinators, Brum, J. R., Ignacio-Espinoza, J. C., Doulcier, S. Roux G., Acinas, S. G., Alberti, A., Chaffron, S., Cruaud, C., de Vargas, C., Gasol, J. M., Gorsky, G., Gregory, A. C., Guidi, L., Hingamp, P., Iudicone, D., Not, F., Ogata, H., Pesant, S., Poulos, B. T., Schwenck, S. M., Speich, S., Dimier, C., Kandels-Lewis, S., Picheral, M., Searson, S., Bork, P., Bowler, C., Sunagawa, S., Wincker, P., Karsenti, E., and Sullivan, M. B.

Published
2015

12. Functional repertoire convergence of distantly related eukaryotic plankton lineages abundant in the sunlit ocean

Author

Delmont, T.O., Gaia, M., Hinsinger, D.D., Frémont, P., Vanni, C., Fernandez-Guerra, A., Eren, A.M., Kourlaiev, A., d'Agata, L., Clayssen, Q., Villar, E., Labadie, K., Cruaud, C., Poulain, J., Da Silva, C., Wessner, M., Noel, B., Aury, J.M., de Vargas, C., Bowler, C., Karsenti, E., Pelletier, E., Wincker, P., and Jaillon, O.

Subjects
Cardiovascular and Metabolic Diseases, fungi
Abstract

Marine planktonic eukaryotes play critical roles in global biogeochemical cycles and climate. However, their poor representation in culture collections limits our understanding of the evolutionary history and genomic underpinnings of planktonic ecosystems. Here, we used 280 billion Tara Oceans metagenomic reads from polar, temperate, and tropical sunlit oceans to reconstruct and manually curate more than 700 abundant and widespread eukaryotic environmental genomes ranging from 10 Mbp to 1.3 Gbp. This genomic resource covers a wide range of poorly characterized eukaryotic lineages that complement long-standing contributions from culture collections while better representing plankton in the upper layer of the oceans. We performed the first, to our knowledge, comprehensive genome-wide functional classification of abundant unicellular eukaryotic plankton, revealing four major groups connecting distantly related lineages. Neither trophic modes of plankton nor its vertical evolutionary history could completely explain the functional repertoire convergence of major eukaryotic lineages that coexisted within oceanic currents for millions of years.

Published
2022

13. Eukaryotic plankton diversity in the sunlit ocean

Author

de Vargas, C., Audic, S., Henry, N., Decelle, J., Mahé, F., Logares, R., Lara, E., Berney, C., Le Bescot, N., Probert, I., Carmichael, M., Poulain, J., Romac, S., Colin, S., Aury, J.-M., Bittner, L., Chaffron, S., Dunthorn, M., Engelen, S., Flegontova, O., Guidi, L., Horák, A., Jaillon, O., Lima-Mendez, G., Lukeš, J., Malviya, S., Morard, R., Mulot, M., Scalco, E., Siano, R., Vincent, F., Zingone, A., Dimier, C., Picheral, M., Searson, S., Kandels-Lewis, S., Oceans Coordinators, Tara, Acinas, S. G., Bork, P., Bowler, C., Gorsky, G., Grimsley, N., Hingamp, P., Iudicone, D., Not, F., Ogata, H., Pesant, S., Raes, J., Sieracki, M. E., Speich, S., Stemmann, L., Sunagawa, S., Weissenbach, J., Wincker, P., and Karsenti, E.

Published
2015

14. Determinants of community structure in the global plankton interactome

Author

Lima-Mendez, G., Faust, K., Henry, N., Decelle, J., Colin, S., Carcillo, F., Chaffron, S., Ignacio-Espinosa, J. C., Roux, S., Vincent, F., Bittner, L., Darzi, Y., Wang, J., Audic, S., Berline, L., Bontempi, G., Cabello, A. M., Coppola, L., Cornejo-Castillo, F. M., dʼOvidio, F., De Meester, L., Ferrera, I., Garet-Delmas, M.-J., Guidi, L., Lara, E., Pesant, S., Royo-Llonch, M., Salazar, G., Sánchez, P., Sebastian, M., Souffreau, C., Dimier, C., Picheral, M., Searson, S., Kandels-Lewis, S., Oceans Coordinators, Tara, Gorsky, G., Not, F., Ogata, H., Speich, S., Stemmann, L., Weissenbach, J., Wincker, P., Acinas, S. G., Sunagawa, S., Bork, P., Sullivan, M. B., Karsenti, E., Bowler, C., de Vargas, C., and Raes, J.

Published
2015

15. Structure and function of the global ocean microbiome

Author

Sunagawa, S., Coelho, L. P., Chaffron, S., Kultima, J. R., Labadie, K., Salazar, G., Djahanschiri, B., Zeller, G., Mende, D. R., Alberti, A., Cornejo-Castillo, F. M., Costea, P. I., Cruaud, C., dʼOvidio, F., Engelen, S., Ferrera, I., Gasol, J. M., Guidi, L., Hildebrand, F., Kokoszka, F., Lepoivre, C., Lima-Mendez, G., Poulain, J., Poulos, B. T., Royo-Llonch, M., Sarmento, H., Vieira-Silva, S., Dimier, C., Picheral, M., Searson, S., Kandels-Lewis, S., Oceans Coordinators, Tara, Bowler, C., de Vargas, C., Gorsky, G., Grimsley, N., Hingamp, P., Iudicone, D., Jaillon, O., Not, F., Ogata, H., Pesant, S., Speich, S., Stemmann, L., Sullivan, M. B., Weissenbach, J., Wincker, P., Karsenti, E., Raes, J., Acinas, S. G., and Bork, P.

Published
2015

16. Environmental characteristics of Agulhas rings affect interocean plankton transport

Author

Villar, E., Farrant, G. K., Follows, M., Garczarek, L., Speich, S., Audic, S., Bittner, L., Blanke, B., Brum, J. R., Brunet, C., Casotti, R., Chase, A., Dolan, J. R., dʼOrtenzio, F., Gattuso, J.-P., Grima, N., Guidi, L., Hill, C. N., Jahn, O., Jamet, J.-L., Le Goff, H., Lepoivre, C., Malviya, S., Pelletier, E., Romagnan, J.-B., Roux, S., Santini, S., Scalco, E., Schwenck, S. M., Tanaka, A., Testor, P., Vannier, T., Vincent, F., Zingone, A., Dimier, C., Picheral, M., Searson, S., Kandels-Lewis, S., Oceans Coordinators, Tara, Acinas, S. G., Bork, P., Boss, E., de Vargas, C., Gorsky, G., Ogata, H., Pesant, S., Sullivan, M. B., Sunagawa, S., Wincker, P., Karsenti, E., Bowler, C., Not, F., Hingamp, P., and Iudicone, D.

Published
2015

17. Patterns and ecological drivers of ocean viral communities

Author

Brum, J. R., Ignacio-Espinoza, J. C., Roux, S., Doulcier, G., Acinas, S. G., Alberti, A., Chaffron, S., Cruaud, C., de Vargas, C., Gasol, J. M., Gorsky, G., Gregory, A. C., Guidi, L., Hingamp, P., Iudicone, D., Not, F., Ogata, H., Pesant, S., Poulos, B. T., Schwenck, S. M., Speich, S., Dimier, C., Kandels-Lewis, S., Picheral, M., Searson, S., Oceans Coordinators, Tara, Bork, P., Bowler, C., Sunagawa, S., Wincker, P., Karsenti, E., and Sullivan, M. B.

Published
2015

22. Plankton networks correlated to the biological carbon pump in the global ocean

Author

Benoiston, A.S., Bittner, L., Guidi, Lionel, Chaffron, S., Eveillard, D., Ayata, S.D., Jean, Géraldine, Pelletier, E., Pesant, S., de Vargas, C., Karsenti, E., Bowler, C., Gorsky, G., Consortium, Tara, Institut de Systématique, Evolution, Biodiversité (ISYEB ), Muséum national d'Histoire naturelle (MNHN)-École Pratique des Hautes Études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles (UA), Laboratoire d'océanographie de Villefranche (LOV), Observatoire océanologique de Villefranche-sur-mer (OOVM), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Combinatoire et Bioinformatique (LS2N - équipe COMBI), Laboratoire des Sciences du Numérique de Nantes (LS2N), Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-École Centrale de Nantes (ECN)-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), Laboratoire d'Informatique de Nantes Atlantique (LINA), Mines Nantes (Mines Nantes)-Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de la Mer de Villefranche (IMEV), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut National de Recherche en Informatique et en Automatique (Inria)-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-École Centrale de Nantes (Nantes Univ - ECN), Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ)-Nantes université - UFR des Sciences et des Techniques (Nantes univ - UFR ST), Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ)-Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Institut National de Recherche en Informatique et en Automatique (Inria)-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique (IMT Atlantique), Nantes Université (Nantes Univ), Genoscope - Centre national de séquençage [Evry] (GENOSCOPE), Université Paris-Saclay-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Center for Marine Environmental Sciences [Bremen] (MARUM), Universität Bremen, Data Publisher for Earth and Environmental Science (PANGAEA), University of Bremen, Station biologique de Roscoff (SBR), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut de biologie de l'ENS Paris (IBENS), Département de Biologie - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography
Abstract

International audience

Published
2017

23. A new sequence data set of SSU rRNA gene for Scleractinia and its phylogenetic and ecological applications

Author

Arrigoni, R, Vacherie, B, Benzoni, F, Stefani, F, Karsenti, E, Jaillon, O, Not, F, Nunes, F, Payri, C, Wincker, P, Barbe, V, Arrigoni, R, Vacherie, B, Benzoni, F, Stefani, F, Karsenti, E, Jaillon, O, Not, F, Nunes, F, Payri, C, Wincker, P, and Barbe, V

Abstract

Scleractinian corals (i.e. hard corals) play a fundamental role in building and maintaining coral reefs, one of the most diverse ecosystems on Earth. Nevertheless, their phylogenies remain largely unresolved and little is known about dispersal and survival of their planktonic larval phase. The small subunit ribosomal RNA (SSU rRNA) is a commonly used gene for DNA barcoding in several metazoans, and small variable regions of SSU rRNA are widely adopted as barcode marker to investigate marine plankton community structure worldwide. Here, we provide a large sequence data set of the complete SSU rRNA gene from 298 specimens, representing all known extant reef coral families and a total of 106 genera. The secondary structure was extremely conserved within the order with few exceptions due to insertions or deletions occurring in the variable regions. Remarkable differences in SSU rRNA length and base composition were detected between and within acroporids (Acropora, Montipora, Isopora and Alveopora) compared to other corals. The V4 and V9 regions seem to be promising barcode loci because variation at commonly used barcode primer binding sites was extremely low, while their levels of divergence allowed families and genera to be distinguished. A time-calibrated phylogeny of Scleractinia is provided, and mutation rate heterogeneity is demonstrated across main lineages. The use of this data set as a valuable reference for investigating aspects of ecology, biology, molecular taxonomy and evolution of scleractinian corals is discussed.

Published
2017

25. Effects of XMAP215 on microtubule dynamics and structure

Author

Coquelle, Frédéric, Kinoshita, K., Vitre, Benjamin, Rybina, S., Heichette, Claire, Karsenti, E., Chrétien, Denis, Arnal, Isabelle, Interactions cellulaires et moléculaires (ICM), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), De Villemeur, Hervé, and Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SDV.BBM.BS]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biomolecules [q-bio.BM], [SDV.BBM.BS]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Structural Biology [q-bio.BM], [SDV.BBM.BS] Life Sciences [q-bio]/Biochemistry, Molecular Biology/Structural Biology [q-bio.BM], ComputingMethodologies_GENERAL, ComputingMilieux_MISCELLANEOUS
Abstract

Poster; International audience

Published
2008

26. A Holistic Approach to Marine Eco-Systems Biology

Author

Karsenti, E, Acinas, S, Bork, P, Bowler, C, De Vargas, C, Raes, J, Sullivan, M, Arendt, D, Benzoni, F, Claverie, J, Follows, M, Gorsky, G, Hingamp, P, Iudicone, D, Jaillon, O, Kandels-Lewis, S, Krzic, U, Not, F, Ogata, H, Pesant, S, Reynaud, E, Sardet, C, Sieracki, M, Speich, S, Velayoudon, D, Weissenbach, J, Wincker, P, Acinas, SG, Claverie, J-M, Reynaud, EG, Sieracki, ME, Karsenti, E, Acinas, S, Bork, P, Bowler, C, De Vargas, C, Raes, J, Sullivan, M, Arendt, D, Benzoni, F, Claverie, J, Follows, M, Gorsky, G, Hingamp, P, Iudicone, D, Jaillon, O, Kandels-Lewis, S, Krzic, U, Not, F, Ogata, H, Pesant, S, Reynaud, E, Sardet, C, Sieracki, M, Speich, S, Velayoudon, D, Weissenbach, J, Wincker, P, Acinas, SG, Claverie, J-M, Reynaud, EG, and Sieracki, ME

Published
2011

27. Spindle assembly in Xenopus egg extracts: respective roles of centrosomes and microtubule self-organization.

Author

Heald, R, Heald, R, Tournebize, R, Habermann, A, Karsenti, E, Hyman, A, Heald, R, Heald, R, Tournebize, R, Habermann, A, Karsenti, E, and Hyman, A

Abstract

In Xenopus egg extracts, spindles assembled around sperm nuclei contain a centrosome at each pole, while those assembled around chromatin beads do not. Poles can also form in the absence of chromatin, after addition of a microtubule stabilizing agent to extracts. Using this system, we have asked (a) how are spindle poles formed, and (b) how does the nucleation and organization of microtubules by centrosomes influence spindle assembly? We have found that poles are morphologically similar regardless of their origin. In all cases, microtubule organization into poles requires minus end-directed translocation of microtubules by cytoplasmic dynein, which tethers centrosomes to spindle poles. However, in the absence of pole formation, microtubules are still sorted into an antiparallel array around mitotic chromatin. Therefore, other activities in addition to dynein must contribute to the polarized orientation of microtubules in spindles. When centrosomes are present, they provide dominant sites for pole formation. Thus, in Xenopus egg extracts, centrosomes are not necessarily required for spindle assembly but can regulate the organization of microtubules into a bipolar array.

Published
1997

29. Fertilization of Xenopus eggs imposes a complete translational arrest of mRNAs containing 3'UUAUUUAU elements.

Author

Marinx, Olivier, Bertrand, Sophie, Karsenti, E, Huez, Georges, Kruys, Véronique, Marinx, Olivier, Bertrand, Sophie, Karsenti, E, Huez, Georges, and Kruys, Véronique

Abstract

The early embryonic development of Xenopus is mainly governed by post-transcriptional regulations until the mid-blastula transition. In this report, we present evidence demonstrating that fertilization of Xenopus eggs triggers a complete translational arrest of mRNAs containing UA-rich elements in their 3'-untranslated region. This control is maintained at least until the mid-blastula transition. Neither maturation nor pseudo-fertilization of the egg is sufficient for triggering this control, suggesting that components originating from the male gamete are involved in the mechanism. Moreover, this control is exerted whether the mRNA is polyadenylated or not., In Vitro, Journal Article, Research Support, Non-U.S. Gov't, SCOPUS: ar.j, info:eu-repo/semantics/published

Published
1994

30. Cdc2 phosphorylation is required for its interaction with cyclin

Author

Ducommun, B, Brambilla, P, Félix, M, Franza, B, Karsenti, E, Draetta, G, Draetta, G., BRAMBILLA, PAOLO, Ducommun, B, Brambilla, P, Félix, M, Franza, B, Karsenti, E, Draetta, G, Draetta, G., and BRAMBILLA, PAOLO

Abstract

Activation of the cdc2 protein kinase at different stages of the cell cycle is regulated by post-translational modifications and interactions with cyclins. We show that in vitro translated human cdc2 binds very poorly to A and B cyclins, unless it has been preincubated with a Xenopus egg extract. This results in the phosphorylation of cdc2 which allows binding to cyclins. The replacement of Thr161, a residue conserved and phosphorylated in other protein kinases, with valine inhibits cdc2 association with A and B cyclins. In addition, mutations in the amino-terminus of cdc2 and within the conserved 'PSTAIR' region strongly inhibit binding. The Thr161Val mutation causes a lethal phenotype in the fission yeast Schizosaccharomyces pombe, while replacement of Thr161 with glutamic acid, potentially mimicking phosphorylation, causes uncoordination of mitosis and multiple cytokinesis. These results suggest that a threonine phosphorylation/dephosphorylation cycle is involved in regulating cdc2 function

Published
1991

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