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Aguileta G, Lengelle J, Marthey S, Chiapello H, Rodolphe F, Gendrault A, Yockteng R, Vercken E, Devier B, Fontaine MC, Wincker P, Dossat C, Cruaud C, Couloux A, Giraud T. Finding candidate genes under positive selection in Non-model species: examples of genes involved in host specialization in pathogens. Mol Ecol 2009; 19:292-306. [PMID: 20041992 DOI: 10.1111/j.1365-294x.2009.04454.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Numerous genes in diverse organisms have been shown to be under positive selection, especially genes involved in reproduction, adaptation to contrasting environments, hybrid inviability, and host-pathogen interactions. Looking for genes under positive selection in pathogens has been a priority in efforts to investigate coevolution dynamics and to develop vaccines or drugs. To elucidate the functions involved in host specialization, here we aimed at identifying candidate sequences that could have evolved under positive selection among closely related pathogens specialized on different hosts. For this goal, we sequenced c. 17,000-32,000 ESTs from each of four Microbotryum species, which are fungal pathogens responsible for anther smut disease on host plants in the Caryophyllaceae. Forty-two of the 372 predicted orthologous genes showed significant signal of positive selection, which represents a good number of candidate genes for further investigation. Sequencing 16 of these genes in 9 additional Microbotryum species confirmed that they have indeed been rapidly evolving in the pathogen species specialized on different hosts. The genes showing significant signals of positive selection were putatively involved in nutrient uptake from the host, secondary metabolite synthesis and secretion, respiration under stressful conditions and stress response, hyphal growth and differentiation, and regulation of expression by other genes. Many of these genes had transmembrane domains and may therefore also be involved in pathogen recognition by the host. Our approach thus revealed fruitful and should be feasible for many non-model organisms for which candidate genes for diversifying selection are needed.
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Affiliation(s)
- G Aguileta
- Ecologie, Systématique et Evolution, Université Paris-Sud, F-91405 Orsay cedex, France
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3
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Ljungvall J, Görgen A, Girod M, Delaroche JP, Dewald A, Dossat C, Farnea E, Korten W, Melon B, Menegazzo R, Obertelli A, Orlandi R, Petkov P, Pissulla T, Siem S, Singh RP, Srebrny J, Theisen CH, Ur CA, Valiente-Dobón JJ, Zell KO, Zielińska M. Shape coexistence in light se isotopes: evidence for oblate shapes. Phys Rev Lett 2008; 100:102502. [PMID: 18352179 DOI: 10.1103/physrevlett.100.102502] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2007] [Indexed: 05/26/2023]
Abstract
Lifetimes of states in the ground-state bands of (70)Se and (72)Se were measured using the recoil-distance Doppler shift method. The results deviate significantly from earlier measurements, requiring a revision of the conclusions drawn from a recent Coulomb excitation experiment concerning the shape of (70)Se. The new results lead to a coherent picture of shape coexistence in the neutron-deficient selenium and krypton isotopes. The coexistence and evolution of oblate and prolate shapes in this mass region is for the first time consistently described by new Hartree-Fock-Bogolyubov-based configuration-mixing calculations which were performed using the Gogny D1S interaction.
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Affiliation(s)
- J Ljungvall
- CEA-Saclay, DAPNIA/SPhN, F-91191 Gif-sur-Yvette Cedex, France
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4
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Giovinazzo J, Blank B, Borcea C, Canchel G, Dalouzy JC, Demonchy CE, de Oliveira Santos F, Dossat C, Grévy S, Hay L, Huikari J, Leblanc S, Matea I, Pedroza JL, Perrot L, Pibernat J, Serani L, Stodel C, Thomas JC. First direct observation of two protons in the decay of 45Fe with a time-projection chamber. Phys Rev Lett 2007; 99:102501. [PMID: 17930383 DOI: 10.1103/physrevlett.99.102501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2007] [Indexed: 05/25/2023]
Abstract
The decay of the ground-state two-proton emitter 45Fe was studied with a time-projection chamber and the emission of two protons was unambiguously identified. The total decay energy and the half-life measured in this work agree with the results from previous experiments. The present result constitutes the first direct observation of the individual protons in the two-proton decay of a long-lived ground-state emitter. In parallel, we identified for the first time directly two-proton emission from 43Cr, a known beta-delayed two-proton emitter. The technique developed in the present work opens the way to a detailed study of the mechanism of ground state as well as beta-delayed two-proton radioactivity.
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Affiliation(s)
- J Giovinazzo
- Centre d'Etudes Nucléaires de Bordeaux Gradignan-Université Bordeaux 1-UMR 5797 CNRS/IN2P3, Chemin du Solarium, BP 120, F-33175 Gradignan Cedex, France
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5
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Muller D, Médigue C, Koechler S, Barbe V, Barakat M, Talla E, Bonnefoy V, Krin E, Arsène-Ploetze F, Carapito C, Chandler M, Cournoyer B, Cruveiller S, Dossat C, Duval S, Heymann M, Leize E, Lieutaud A, Lièvremont D, Makita Y, Mangenot S, Nitschke W, Ortet P, Perdrial N, Schoepp B, Siguier P, Simeonova DD, Rouy Z, Segurens B, Turlin E, Vallenet D, Dorsselaer AV, Weiss S, Weissenbach J, Lett MC, Danchin A, Bertin PN. A tale of two oxidation states: bacterial colonization of arsenic-rich environments. PLoS Genet 2007; 3:e53. [PMID: 17432936 PMCID: PMC1851979 DOI: 10.1371/journal.pgen.0030053] [Citation(s) in RCA: 151] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2006] [Accepted: 02/23/2007] [Indexed: 12/03/2022] Open
Abstract
Microbial biotransformations have a major impact on contamination by toxic elements, which threatens public health in developing and industrial countries. Finding a means of preserving natural environments—including ground and surface waters—from arsenic constitutes a major challenge facing modern society. Although this metalloid is ubiquitous on Earth, thus far no bacterium thriving in arsenic-contaminated environments has been fully characterized. In-depth exploration of the genome of the β-proteobacterium Herminiimonas arsenicoxydans with regard to physiology, genetics, and proteomics, revealed that it possesses heretofore unsuspected mechanisms for coping with arsenic. Aside from multiple biochemical processes such as arsenic oxidation, reduction, and efflux, H. arsenicoxydans also exhibits positive chemotaxis and motility towards arsenic and metalloid scavenging by exopolysaccharides. These observations demonstrate the existence of a novel strategy to efficiently colonize arsenic-rich environments, which extends beyond oxidoreduction reactions. Such a microbial mechanism of detoxification, which is possibly exploitable for bioremediation applications of contaminated sites, may have played a crucial role in the occupation of ancient ecological niches on earth. Microorganisms play a crucial role in nutrient biogeochemical cycles. Arsenic is found throughout the environment from both natural and anthropogenic sources. Its inorganic forms are highly toxic and impair the physiology of most higher organisms. Arsenic contamination of groundwater supplies is giving rise to increasingly severe human health problems in both developing and industrial countries. In the present work, we investigated the metabolism of this metalloid in Herminiimonas arsenicoxydans, a representative organism of a novel bacterial genus widespread in aquatic environments. Examination of the genome sequence and experimental evidence revealed that it is remarkably capable of coping with arsenic. Our observations support the existence of multiple strategies allowing arsenic-metabolizing microbes to efficiently colonize toxic environments. In particular, arsenic oxidation and scavenging may have played a crucial role in the development of early stages of life on Earth. Such mechanisms may one day be exploited as part of a potential bioremediation strategy in toxic environments.
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Affiliation(s)
- Daniel Muller
- Génétique Moléculaire, Génomique et Microbiologie, UMR7156 CNRS and Université Louis Pasteur, Strasbourg, France
| | | | - Sandrine Koechler
- Génétique Moléculaire, Génomique et Microbiologie, UMR7156 CNRS and Université Louis Pasteur, Strasbourg, France
| | | | - Mohamed Barakat
- Laboratoire d'Écologie Microbienne de la Rhizosphère et d'Environnements Extrêmes, UMR6191 CNRS, CEA and Université Aix-Marseille II, Saint-Paul-lez-Durance, France
| | - Emmanuel Talla
- Laboratoire de Chimie Bactérienne, UPR9043 CNRS, Institut de Biologie Structurale et Microbiologie, Marseille, France
| | - Violaine Bonnefoy
- Laboratoire de Chimie Bactérienne, UPR9043 CNRS, Institut de Biologie Structurale et Microbiologie, Marseille, France
| | - Evelyne Krin
- Génétique des Génomes Bactériens, URA2171, Institut Pasteur, Paris, France
| | - Florence Arsène-Ploetze
- Génétique Moléculaire, Génomique et Microbiologie, UMR7156 CNRS and Université Louis Pasteur, Strasbourg, France
| | - Christine Carapito
- Laboratoire de Spectrométrie de Masse Bio-Organique, Institut Pluridisciplinaire Hubert Curien, UMR7178 CNRS and Université Louis Pasteur, Strasbourg, France
| | - Michael Chandler
- Laboratoire de Microbiologie et Génétique Moléculaires, UMR5100 CNRS, Toulouse, France
| | - Benoît Cournoyer
- Ecologie Microbienne, UMR5557 CNRS and Université Claude Bernard–Lyon 1, Villeurbanne, France
| | | | | | - Simon Duval
- Laboratoire de Bioénergétique et Ingénierie des Protéines, UPR9036 CNRS, Institut de Biologie Structurale et Microbiologie, Marseille, France
| | - Michael Heymann
- Génétique Moléculaire, Génomique et Microbiologie, UMR7156 CNRS and Université Louis Pasteur, Strasbourg, France
| | - Emmanuelle Leize
- Laboratoire de Spectrométrie de Masse Bio-Organique, Institut Pluridisciplinaire Hubert Curien, UMR7178 CNRS and Université Louis Pasteur, Strasbourg, France
| | - Aurélie Lieutaud
- Laboratoire de Chimie Bactérienne, UPR9043 CNRS, Institut de Biologie Structurale et Microbiologie, Marseille, France
| | - Didier Lièvremont
- Génétique Moléculaire, Génomique et Microbiologie, UMR7156 CNRS and Université Louis Pasteur, Strasbourg, France
| | - Yuko Makita
- Génétique des Génomes Bactériens, URA2171, Institut Pasteur, Paris, France
| | | | - Wolfgang Nitschke
- Laboratoire de Bioénergétique et Ingénierie des Protéines, UPR9036 CNRS, Institut de Biologie Structurale et Microbiologie, Marseille, France
| | - Philippe Ortet
- Laboratoire d'Écologie Microbienne de la Rhizosphère et d'Environnements Extrêmes, UMR6191 CNRS, CEA and Université Aix-Marseille II, Saint-Paul-lez-Durance, France
| | - Nicolas Perdrial
- Centre de Géochimie de la Surface, UMR7517 CNRS and Université Louis Pasteur, Strasbourg, France
| | - Barbara Schoepp
- Laboratoire de Bioénergétique et Ingénierie des Protéines, UPR9036 CNRS, Institut de Biologie Structurale et Microbiologie, Marseille, France
| | - Patricia Siguier
- Laboratoire de Microbiologie et Génétique Moléculaires, UMR5100 CNRS, Toulouse, France
| | - Diliana D Simeonova
- Génétique Moléculaire, Génomique et Microbiologie, UMR7156 CNRS and Université Louis Pasteur, Strasbourg, France
| | - Zoé Rouy
- Génoscope, UMR8030 CNRS, Evry Cedex, France
| | | | - Evelyne Turlin
- Génétique des Génomes Bactériens, URA2171, Institut Pasteur, Paris, France
| | | | - Alain Van Dorsselaer
- Laboratoire de Spectrométrie de Masse Bio-Organique, Institut Pluridisciplinaire Hubert Curien, UMR7178 CNRS and Université Louis Pasteur, Strasbourg, France
| | - Stéphanie Weiss
- Génétique Moléculaire, Génomique et Microbiologie, UMR7156 CNRS and Université Louis Pasteur, Strasbourg, France
| | | | - Marie-Claire Lett
- Génétique Moléculaire, Génomique et Microbiologie, UMR7156 CNRS and Université Louis Pasteur, Strasbourg, France
| | - Antoine Danchin
- Génétique des Génomes Bactériens, URA2171, Institut Pasteur, Paris, France
| | - Philippe N Bertin
- Génétique Moléculaire, Génomique et Microbiologie, UMR7156 CNRS and Université Louis Pasteur, Strasbourg, France
- * To whom correspondence should be addressed. E-mail:
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6
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Blank B, Bey A, Canchel G, Dossat C, Fleury A, Giovinazzo J, Matea I, Adimi N, De Oliveira F, Stefan I, Georgiev G, Grévy S, Thomas JC, Borcea C, Cortina D, Caamano M, Stanoiu M, Aksouh F, Brown BA, Barker FC, Richter WA. First observation of 54Zn and its decay by two-proton emission. Phys Rev Lett 2005; 94:232501. [PMID: 16090464 DOI: 10.1103/physrevlett.94.232501] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2005] [Indexed: 05/03/2023]
Abstract
The nucleus 54Zn has been observed for the first time in an experiment at the SISSI/LISE3 facility of GANIL in the quasifragmentation of a 58Ni beam at 74.5 MeV/nucleon in a (nat)Ni target. The fragments were analyzed by means of the ALPHA-LISE3 separator and implanted in a silicon-strip detector where correlations in space and time between implantation and subsequent decay events allowed us to generate almost background free decay spectra for about 25 different nuclei at the same time. Eight 54Zn implantation events were observed. From the correlated decay events, the half-life of 54Zn is determined to be 3.2(+1.8)(-0.8) ms. Seven of the eight implantations are followed by two-proton emission with a decay energy of 1.48(2) MeV. The decay energy and the partial half-life are compared to model predictions and allow for a test of these two-proton decay models.
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Affiliation(s)
- B Blank
- CENBG, Le Haut Vigneau, F-33175 Gradignan Cedex, France
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