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Six C, Ratin M, Marie D, Corre E. Marine Synechococcus picocyanobacteria: Light utilization across latitudes. Proc Natl Acad Sci U S A 2021; 118:e2111300118. [PMID: 34518213 PMCID: PMC8463805 DOI: 10.1073/pnas.2111300118] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/03/2021] [Indexed: 02/08/2023] Open
Abstract
The most ubiquitous cyanobacteria, Synechococcus, have colonized different marine thermal niches through the evolutionary specialization of lineages adapted to different ranges of temperature seawater. We used the strains of Synechococcus temperature ecotypes to study how light utilization has evolved in the function of temperature. The tropical Synechococcus (clade II) was unable to grow under 16 °C but, at temperatures >25 °C, induced very high growth rates that relied on a strong synthesis of the components of the photosynthetic machinery, leading to a large increase in photosystem cross-section and electron flux. By contrast, the Synechococcus adapted to subpolar habitats (clade I) grew more slowly but was able to cope with temperatures <10 °C. We show that growth at such temperatures was accompanied by a large increase of the photoprotection capacities using the orange carotenoid protein (OCP). Metagenomic analyzes revealed that Synechococcus natural communities show the highest prevalence of the ocp genes in low-temperature niches, whereas most tropical clade II Synechococcus have lost the gene. Moreover, bioinformatic analyzes suggested that the OCP variants of the two cold-adapted Synechococcus clades I and IV have undergone evolutionary convergence through the adaptation of the molecular flexibility. Our study points to an important role of temperature in the evolution of the OCP. We, furthermore, discuss the implications of the different metabolic cost of these physiological strategies on the competitiveness of Synechococcus in a warming ocean. This study can help improve the current hypotheses and models aimed at predicting the changes in ocean carbon fluxes in response to global warming.
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Affiliation(s)
- Christophe Six
- Centre National de la Recherche Scientifique, Sorbonne Université, UMR 7144, Adaptation et Diversité en Milieu Marin, group Ecology of Marine Plankton, Station Biologique de Roscoff, 29680 Roscoff, France;
| | - Morgane Ratin
- Centre National de la Recherche Scientifique, Sorbonne Université, UMR 7144, Adaptation et Diversité en Milieu Marin, group Ecology of Marine Plankton, Station Biologique de Roscoff, 29680 Roscoff, France
| | - Dominique Marie
- Centre National de la Recherche Scientifique, Sorbonne Université, UMR 7144, Adaptation et Diversité en Milieu Marin, group Ecology of Marine Plankton, Station Biologique de Roscoff, 29680 Roscoff, France
| | - Erwan Corre
- Department Analysis and Bioinformatics for Marine Science, Fédération de Recherche 2424, 29680 Roscoff, France
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Qui-Minet ZN, Davoult D, Grall J, Delaunay C, Six C, Cariou T, Martin S. Physiology of maerl algae: Comparison of inter- and intraspecies variations. J Phycol 2021; 57:831-848. [PMID: 33316844 DOI: 10.1111/jpy.13119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 10/09/2020] [Accepted: 11/08/2020] [Indexed: 06/12/2023]
Abstract
Free-living red coralline algae play an important role in the carbon and carbonate cycles of coastal environments. In this study, we examined the physiology of free-living coralline algae-forming maerl beds in the Bay of Brest (Brittany, France), where Lithothamnion corallioides is the dominant maerl (i.e., rhodolith) species. Phymatolithon calcareum and Lithophyllum incrustans are also present (in lower abundances) at a specific site in the bay. We aimed to assess how maerl physiology is affected by seasonality and/or local environmental variations at the inter- and intraspecific levels. Physiological measurements (respiration, photosynthetic, and calcification rates) were performed using incubation chambers in winter and summer to compare (1) the dominant maerl species at three sites and (2) three coexisting maerl species at one site. Comparison of the three coexisting maerl species suggests that L. corallioides is the best adapted to the current environmental conditions in the Bay of Brest, because this species is the most robust to dissolution in the dark in winter and has the highest calcification efficiency in the light. Comparisons of L. corallioides metabolic rates between stations showed that morphological variations within this species are the main factor affecting its photosynthetic and calcification rates. Environmental factors such as freshwater inputs also affect its calcification rates in the dark. In addition to interspecies variation in maerl physiology, there were intraspecific variations associated with direct (water physico-chemistry) or indirect (morphology) local environmental conditions. This study demonstrates the plasticity of maerl physiology in response to environmental changes, which is fundamental for maerl persistence.
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Affiliation(s)
- Zujaila Nohemy Qui-Minet
- CNRS, UMR 7144 Adaptation et Diversité en Milieu Marin, Station Biologique de Roscoff, Sorbonne Université, Place Georges Teissier, 29688, Roscoff Cedex, France
| | - Dominique Davoult
- CNRS, UMR 7144 Adaptation et Diversité en Milieu Marin, Station Biologique de Roscoff, Sorbonne Université, Place Georges Teissier, 29688, Roscoff Cedex, France
| | - Jacques Grall
- IUEM, Université de Bretagne Occidentale, Place Nicolas Copernic, 29280, Plouzané, France
| | - Coralie Delaunay
- CNRS, UMR 7144 Adaptation et Diversité en Milieu Marin, Station Biologique de Roscoff, Sorbonne Université, Place Georges Teissier, 29688, Roscoff Cedex, France
| | - Christophe Six
- CNRS, UMR 7144 Adaptation et Diversité en Milieu Marin, Station Biologique de Roscoff, Sorbonne Université, Place Georges Teissier, 29688, Roscoff Cedex, France
| | - Thierry Cariou
- CNRS, Fédération de Recherche FR2424, Station Biologique de Roscoff, Sorbonne Université, Place Georges Teissier, 29680, Roscoff, France
| | - Sophie Martin
- CNRS, UMR 7144 Adaptation et Diversité en Milieu Marin, Station Biologique de Roscoff, Sorbonne Université, Place Georges Teissier, 29688, Roscoff Cedex, France
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Chaumont S, Quinquis L, Monnerie B, Six C, Hebel P, Duracinsky M, Chassany O, Le Nevé B. Une alimentation de moindre qualité nutritionnelle est associée à des symptômes digestifs plus fréquents affectant la qualité de vie des adultes Français. NUTR CLIN METAB 2021. [DOI: 10.1016/j.nupar.2021.01.079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Kayal E, Alves-de-Souza C, Farhat S, Velo-Suarez L, Monjol J, Szymczak J, Bigeard E, Marie D, Noel B, Porcel BM, Corre E, Six C, Guillou L. Dinoflagellate Host Chloroplasts and Mitochondria Remain Functional During Amoebophrya Infection. Front Microbiol 2020; 11:600823. [PMID: 33424803 PMCID: PMC7793755 DOI: 10.3389/fmicb.2020.600823] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 11/19/2020] [Indexed: 11/13/2022] Open
Abstract
Dinoflagellates are major components of phytoplankton that play critical roles in many microbial food webs, many of them being hosts of countless intracellular parasites. The phototrophic dinoflagellate Scrippsiella acuminata (Dinophyceae) can be infected by the microeukaryotic parasitoids Amoebophrya spp. (Syndiniales), some of which primarily target and digest the host nucleus. Early digestion of the nucleus at the beginning of the infection is expected to greatly impact the host metabolism, inducing the knockout of the organellar machineries that highly depend upon nuclear gene expression, such as the mitochondrial OXPHOS pathway and the plastid photosynthetic carbon fixation. However, previous studies have reported that chloroplasts remain functional in swimming host cells infected by Amoebophrya. We report here a multi-approach monitoring study of S. acuminata organelles over a complete infection cycle by nucleus-targeting Amoebophrya sp. strain A120. Our results show sustained and efficient photosystem II activity as a hallmark of functional chloroplast throughout the infection period despite the complete digestion of the host nucleus. We also report the importance played by light on parasite production, i.e., the amount of host biomass converted to parasite infective propagules. Using a differential gene expression analysis, we observed an apparent increase of all 3 mitochondrial and 9 out of the 11 plastidial genes involved in the electron transport chains (ETC) of the respiration pathways during the first stages of the infection. The longer resilience of organellar genes compared to those encoded by the nucleus suggests that both mitochondria and chloroplasts remain functional throughout most of the infection. This extended organelle functionality, along with higher parasite production under light conditions, suggests that host bioenergetic organelles likely benefit the parasite Amoebophrya sp. A120 and improve its fitness during the intracellular infective stage.
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Affiliation(s)
- Ehsan Kayal
- Fédération de Recherche 2424 Sorbonne Université & Centre National pour la Recherche Scientifique, Station Biologique de Roscoff, Roscoff, France
| | - Catharina Alves-de-Souza
- Algal Resources Collection, Center for Marine Sciences, University of North Carolina Wilmington, Wilmington, NC, United States
| | - Sarah Farhat
- Génomique Métabolique, Génoscope, Institut François Jacob, CEA, CNRS, Université d'Evry, Université Paris-Saclay, Evry, France
| | - Lourdes Velo-Suarez
- UMR 1078, Genetics, Functional Genomics and Biotechnology, INSERM. UFR Médecine, Brest, France
| | - Joanne Monjol
- UMR 7144 Sorbonne Université & Centre National pour la Recherche Scientifique, «Adaptation and Diversity in Marine Environment», Team «Ecology of Marine Plankton, ECOMAP», Station Biologique de Roscoff, Roscoff, France
| | - Jeremy Szymczak
- UMR 7144 Sorbonne Université & Centre National pour la Recherche Scientifique, «Adaptation and Diversity in Marine Environment», Team «Ecology of Marine Plankton, ECOMAP», Station Biologique de Roscoff, Roscoff, France
| | - Estelle Bigeard
- UMR 7144 Sorbonne Université & Centre National pour la Recherche Scientifique, «Adaptation and Diversity in Marine Environment», Team «Ecology of Marine Plankton, ECOMAP», Station Biologique de Roscoff, Roscoff, France
| | - Dominique Marie
- UMR 7144 Sorbonne Université & Centre National pour la Recherche Scientifique, «Adaptation and Diversity in Marine Environment», Team «Ecology of Marine Plankton, ECOMAP», Station Biologique de Roscoff, Roscoff, France
| | - Benjamin Noel
- Génomique Métabolique, Génoscope, Institut François Jacob, CEA, CNRS, Université d'Evry, Université Paris-Saclay, Evry, France
| | - Betina M Porcel
- Génomique Métabolique, Génoscope, Institut François Jacob, CEA, CNRS, Université d'Evry, Université Paris-Saclay, Evry, France
| | - Erwan Corre
- Fédération de Recherche 2424 Sorbonne Université & Centre National pour la Recherche Scientifique, Station Biologique de Roscoff, Roscoff, France
| | - Christophe Six
- UMR 7144 Sorbonne Université & Centre National pour la Recherche Scientifique, «Adaptation and Diversity in Marine Environment», Team «Ecology of Marine Plankton, ECOMAP», Station Biologique de Roscoff, Roscoff, France
| | - Laure Guillou
- UMR 7144 Sorbonne Université & Centre National pour la Recherche Scientifique, «Adaptation and Diversity in Marine Environment», Team «Ecology of Marine Plankton, ECOMAP», Station Biologique de Roscoff, Roscoff, France
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5
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Doré H, Farrant GK, Guyet U, Haguait J, Humily F, Ratin M, Pitt FD, Ostrowski M, Six C, Brillet-Guéguen L, Hoebeke M, Bisch A, Le Corguillé G, Corre E, Labadie K, Aury JM, Wincker P, Choi DH, Noh JH, Eveillard D, Scanlan DJ, Partensky F, Garczarek L. Evolutionary Mechanisms of Long-Term Genome Diversification Associated With Niche Partitioning in Marine Picocyanobacteria. Front Microbiol 2020; 11:567431. [PMID: 33042072 PMCID: PMC7522525 DOI: 10.3389/fmicb.2020.567431] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 08/12/2020] [Indexed: 12/14/2022] Open
Abstract
Marine picocyanobacteria of the genera Prochlorococcus and Synechococcus are the most abundant photosynthetic organisms on Earth, an ecological success thought to be linked to the differential partitioning of distinct ecotypes into specific ecological niches. However, the underlying processes that governed the diversification of these microorganisms and the appearance of niche-related phenotypic traits are just starting to be elucidated. Here, by comparing 81 genomes, including 34 new Synechococcus, we explored the evolutionary processes that shaped the genomic diversity of picocyanobacteria. Time-calibration of a core-protein tree showed that gene gain/loss occurred at an unexpectedly low rate between the different lineages, with for instance 5.6 genes gained per million years (My) for the major Synechococcus lineage (sub-cluster 5.1), among which only 0.71/My have been fixed in the long term. Gene content comparisons revealed a number of candidates involved in nutrient adaptation, a large proportion of which are located in genomic islands shared between either closely or more distantly related strains, as identified using an original network construction approach. Interestingly, strains representative of the different ecotypes co-occurring in phosphorus-depleted waters (Synechococcus clades III, WPC1, and sub-cluster 5.3) were shown to display different adaptation strategies to this limitation. In contrast, we found few genes potentially involved in adaptation to temperature when comparing cold and warm thermotypes. Indeed, comparison of core protein sequences highlighted variants specific to cold thermotypes, notably involved in carotenoid biosynthesis and the oxidative stress response, revealing that long-term adaptation to thermal niches relies on amino acid substitutions rather than on gene content variation. Altogether, this study not only deciphers the respective roles of gene gains/losses and sequence variation but also uncovers numerous gene candidates likely involved in niche partitioning of two key members of the marine phytoplankton.
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Affiliation(s)
- Hugo Doré
- Sorbonne Université, CNRS, UMR 7144 Adaptation and Diversity in the Marine Environment (AD2M), Station Biologique de Roscoff (SBR), Roscoff, France
| | - Gregory K Farrant
- Sorbonne Université, CNRS, UMR 7144 Adaptation and Diversity in the Marine Environment (AD2M), Station Biologique de Roscoff (SBR), Roscoff, France
| | - Ulysse Guyet
- Sorbonne Université, CNRS, UMR 7144 Adaptation and Diversity in the Marine Environment (AD2M), Station Biologique de Roscoff (SBR), Roscoff, France
| | - Julie Haguait
- LS2N, UMR CNRS 6004, IMT Atlantique, ECN, Université de Nantes, Nantes, France
| | - Florian Humily
- Sorbonne Université, CNRS, UMR 7144 Adaptation and Diversity in the Marine Environment (AD2M), Station Biologique de Roscoff (SBR), Roscoff, France
| | - Morgane Ratin
- Sorbonne Université, CNRS, UMR 7144 Adaptation and Diversity in the Marine Environment (AD2M), Station Biologique de Roscoff (SBR), Roscoff, France
| | - Frances D Pitt
- School of Life Sciences, University of Warwick, Coventry, United Kingdom
| | - Martin Ostrowski
- School of Life Sciences, University of Warwick, Coventry, United Kingdom
| | - Christophe Six
- Sorbonne Université, CNRS, UMR 7144 Adaptation and Diversity in the Marine Environment (AD2M), Station Biologique de Roscoff (SBR), Roscoff, France
| | - Loraine Brillet-Guéguen
- CNRS, FR 2424, ABiMS Platform, Station Biologique de Roscoff (SBR), Roscoff, France.,Sorbonne Université, CNRS, UMR 8227, Integrative Biology of Marine Models (LBI2M), Station Biologique de Roscoff (SBR), Roscoff, France
| | - Mark Hoebeke
- CNRS, FR 2424, ABiMS Platform, Station Biologique de Roscoff (SBR), Roscoff, France
| | - Antoine Bisch
- CNRS, FR 2424, ABiMS Platform, Station Biologique de Roscoff (SBR), Roscoff, France
| | - Gildas Le Corguillé
- CNRS, FR 2424, ABiMS Platform, Station Biologique de Roscoff (SBR), Roscoff, France
| | - Erwan Corre
- CNRS, FR 2424, ABiMS Platform, Station Biologique de Roscoff (SBR), Roscoff, France
| | - Karine Labadie
- Genoscope, Institut de Biologie François-Jacob, Commissariat à l'Energie Atomique (CEA), Université Paris-Saclay, Évry, France
| | - Jean-Marc Aury
- Genoscope, Institut de Biologie François-Jacob, Commissariat à l'Energie Atomique (CEA), Université Paris-Saclay, Évry, France
| | - Patrick Wincker
- Génomique Métabolique, Genoscope, Institut de Biologie François Jacob, CEA, CNRS, Université d'Evry, Université Paris-Saclay, Évry, France
| | - Dong Han Choi
- Marine Ecosystem Research Center, Korea Institute of Ocean Science and Technology, Busan, South Korea.,Ocean Science and Technology School, Korea Maritime and Ocean University, Busan, South Korea
| | - Jae Hoon Noh
- Marine Ecosystem Research Center, Korea Institute of Ocean Science and Technology, Busan, South Korea.,Department of Marine Biology, Korea University of Science and Technology, Daejeon, South Korea
| | - Damien Eveillard
- LS2N, UMR CNRS 6004, IMT Atlantique, ECN, Université de Nantes, Nantes, France.,Research Federation (FR2022) Tara Océans GO-SEE, Paris, France
| | - David J Scanlan
- School of Life Sciences, University of Warwick, Coventry, United Kingdom
| | - Frédéric Partensky
- Sorbonne Université, CNRS, UMR 7144 Adaptation and Diversity in the Marine Environment (AD2M), Station Biologique de Roscoff (SBR), Roscoff, France
| | - Laurence Garczarek
- Sorbonne Université, CNRS, UMR 7144 Adaptation and Diversity in the Marine Environment (AD2M), Station Biologique de Roscoff (SBR), Roscoff, France.,Research Federation (FR2022) Tara Océans GO-SEE, Paris, France
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6
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Guyet U, Nguyen NA, Doré H, Haguait J, Pittera J, Conan M, Ratin M, Corre E, Le Corguillé G, Brillet-Guéguen L, Hoebeke M, Six C, Steglich C, Siegel A, Eveillard D, Partensky F, Garczarek L. Synergic Effects of Temperature and Irradiance on the Physiology of the Marine Synechococcus Strain WH7803. Front Microbiol 2020; 11:1707. [PMID: 32793165 PMCID: PMC7393227 DOI: 10.3389/fmicb.2020.01707] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Accepted: 06/29/2020] [Indexed: 11/18/2022] Open
Abstract
Understanding how microorganisms adjust their metabolism to maintain their ability to cope with short-term environmental variations constitutes one of the major current challenges in microbial ecology. Here, the best physiologically characterized marine Synechococcus strain, WH7803, was exposed to modulated light/dark cycles or acclimated to continuous high-light (HL) or low-light (LL), then shifted to various stress conditions, including low (LT) or high temperature (HT), HL and ultraviolet (UV) radiations. Physiological responses were analyzed by measuring time courses of photosystem (PS) II quantum yield, PSII repair rate, pigment ratios and global changes in gene expression. Previously published membrane lipid composition were also used for correlation analyses. These data revealed that cells previously acclimated to HL are better prepared than LL-acclimated cells to sustain an additional light or UV stress, but not a LT stress. Indeed, LT seems to induce a synergic effect with the HL treatment, as previously observed with oxidative stress. While all tested shift conditions induced the downregulation of many photosynthetic genes, notably those encoding PSI, cytochrome b6/f and phycobilisomes, UV stress proved to be more deleterious for PSII than the other treatments, and full recovery of damaged PSII from UV stress seemed to involve the neo-synthesis of a fairly large number of PSII subunits and not just the reassembly of pre-existing subunits after D1 replacement. In contrast, genes involved in glycogen degradation and carotenoid biosynthesis pathways were more particularly upregulated in response to LT. Altogether, these experiments allowed us to identify responses common to all stresses and those more specific to a given stress, thus highlighting genes potentially involved in niche acclimation of a key member of marine ecosystems. Our data also revealed important specific features of the stress responses compared to model freshwater cyanobacteria.
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Affiliation(s)
- Ulysse Guyet
- CNRS, UMR 7144 Adaptation and Diversity in the Marine Environment, Station Biologique de Roscoff, Sorbonne Université, Roscoff, France
| | - Ngoc A Nguyen
- CNRS, UMR 7144 Adaptation and Diversity in the Marine Environment, Station Biologique de Roscoff, Sorbonne Université, Roscoff, France
| | - Hugo Doré
- CNRS, UMR 7144 Adaptation and Diversity in the Marine Environment, Station Biologique de Roscoff, Sorbonne Université, Roscoff, France
| | - Julie Haguait
- LS2N, UMR CNRS 6004, IMT Atlantique, ECN, Université de Nantes, Nantes, France
| | - Justine Pittera
- CNRS, UMR 7144 Adaptation and Diversity in the Marine Environment, Station Biologique de Roscoff, Sorbonne Université, Roscoff, France
| | - Maël Conan
- DYLISS (INRIA-IRISA)-INRIA, CNRS UMR 6074, Université de Rennes 1, Rennes, France
| | - Morgane Ratin
- CNRS, UMR 7144 Adaptation and Diversity in the Marine Environment, Station Biologique de Roscoff, Sorbonne Université, Roscoff, France
| | - Erwan Corre
- CNRS, FR2424, ABiMS, Station Biologique, Sorbonne Université, Roscoff, France
| | - Gildas Le Corguillé
- CNRS, FR2424, ABiMS, Station Biologique, Sorbonne Université, Roscoff, France
| | - Loraine Brillet-Guéguen
- CNRS, FR2424, ABiMS, Station Biologique, Sorbonne Université, Roscoff, France.,CNRS, UMR 8227 Integrative Biology of Marine Models (LBI2M), Station Biologique de Roscoff, Sorbonne Université, Roscoff, France
| | - Mark Hoebeke
- CNRS, FR2424, ABiMS, Station Biologique, Sorbonne Université, Roscoff, France
| | - Christophe Six
- CNRS, UMR 7144 Adaptation and Diversity in the Marine Environment, Station Biologique de Roscoff, Sorbonne Université, Roscoff, France
| | | | - Anne Siegel
- DYLISS (INRIA-IRISA)-INRIA, CNRS UMR 6074, Université de Rennes 1, Rennes, France
| | - Damien Eveillard
- LS2N, UMR CNRS 6004, IMT Atlantique, ECN, Université de Nantes, Nantes, France
| | - Frédéric Partensky
- CNRS, UMR 7144 Adaptation and Diversity in the Marine Environment, Station Biologique de Roscoff, Sorbonne Université, Roscoff, France
| | - Laurence Garczarek
- CNRS, UMR 7144 Adaptation and Diversity in the Marine Environment, Station Biologique de Roscoff, Sorbonne Université, Roscoff, France
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7
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Breton S, Jouhet J, Guyet U, Gros V, Pittera J, Demory D, Partensky F, Doré H, Ratin M, Maréchal E, Nguyen NA, Garczarek L, Six C. Unveiling membrane thermoregulation strategies in marine picocyanobacteria. New Phytol 2020; 225:2396-2410. [PMID: 31591719 DOI: 10.1111/nph.16239] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Accepted: 09/29/2019] [Indexed: 05/23/2023]
Abstract
The wide latitudinal distribution of marine Synechococcus cyanobacteria partly relies on the differentiation of lineages adapted to distinct thermal environments. Membranes are highly thermosensitive cell components, and the ability to modulate their fluidity can be critical for the fitness of an ecotype in a particular thermal niche. We compared the thermophysiology of Synechococcus strains representative of major temperature ecotypes in the field. We measured growth, photosynthetic capacities and membrane lipidome variations. We carried out a metagenomic analysis of stations of the Tara Oceans expedition to describe the latitudinal distribution of the lipid desaturase genes in the oceans. All strains maintained efficient photosynthetic capacities over their different temperature growth ranges. Subpolar and cold temperate strains showed enhanced capacities for lipid monodesaturation at low temperature thanks to an additional, poorly regiospecific Δ9-desaturase. By contrast, tropical and warm temperate strains displayed moderate monodesaturation capacities but high proportions of double unsaturations in response to cold, thanks to regiospecific Δ12-desaturases. The desaturase genes displayed specific distributions directly related to latitudinal variations in ocean surface temperature. This study highlights the critical importance of membrane fluidity modulation by desaturases in the adaptive strategies of Synechococcus cyanobacteria during the colonization of novel thermal niches.
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Affiliation(s)
- Solène Breton
- Sorbonne Université, Centre National de la Recherche Scientifique, UMR 7144 Adaptation et Diversité en Milieu Marin (AD2M), Ecology of Marine Plankton (ECOMAP) Team, Station Biologique de Roscoff (SBR), 29680, Roscoff, France
| | - Juliette Jouhet
- Laboratoire de Physiologie Cellulaire et Végétale, Unité mixe de recherche 5168 CNRS, CEA, INRA, Université Grenoble Alpes, IRIG, CEA Grenoble, 17, rue des Martyrs, 38000, Grenoble, France
| | - Ulysse Guyet
- Sorbonne Université, Centre National de la Recherche Scientifique, UMR 7144 Adaptation et Diversité en Milieu Marin (AD2M), Ecology of Marine Plankton (ECOMAP) Team, Station Biologique de Roscoff (SBR), 29680, Roscoff, France
| | - Valérie Gros
- Laboratoire de Physiologie Cellulaire et Végétale, Unité mixe de recherche 5168 CNRS, CEA, INRA, Université Grenoble Alpes, IRIG, CEA Grenoble, 17, rue des Martyrs, 38000, Grenoble, France
| | - Justine Pittera
- Sorbonne Université, Centre National de la Recherche Scientifique, UMR 7144 Adaptation et Diversité en Milieu Marin (AD2M), Ecology of Marine Plankton (ECOMAP) Team, Station Biologique de Roscoff (SBR), 29680, Roscoff, France
| | - David Demory
- School of Biology, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Frédéric Partensky
- Sorbonne Université, Centre National de la Recherche Scientifique, UMR 7144 Adaptation et Diversité en Milieu Marin (AD2M), Ecology of Marine Plankton (ECOMAP) Team, Station Biologique de Roscoff (SBR), 29680, Roscoff, France
| | - Hugo Doré
- Sorbonne Université, Centre National de la Recherche Scientifique, UMR 7144 Adaptation et Diversité en Milieu Marin (AD2M), Ecology of Marine Plankton (ECOMAP) Team, Station Biologique de Roscoff (SBR), 29680, Roscoff, France
| | - Morgane Ratin
- Sorbonne Université, Centre National de la Recherche Scientifique, UMR 7144 Adaptation et Diversité en Milieu Marin (AD2M), Ecology of Marine Plankton (ECOMAP) Team, Station Biologique de Roscoff (SBR), 29680, Roscoff, France
| | - Eric Maréchal
- Laboratoire de Physiologie Cellulaire et Végétale, Unité mixe de recherche 5168 CNRS, CEA, INRA, Université Grenoble Alpes, IRIG, CEA Grenoble, 17, rue des Martyrs, 38000, Grenoble, France
| | - Ngoc An Nguyen
- Sorbonne Université, Centre National de la Recherche Scientifique, UMR 7144 Adaptation et Diversité en Milieu Marin (AD2M), Ecology of Marine Plankton (ECOMAP) Team, Station Biologique de Roscoff (SBR), 29680, Roscoff, France
| | - Laurence Garczarek
- Sorbonne Université, Centre National de la Recherche Scientifique, UMR 7144 Adaptation et Diversité en Milieu Marin (AD2M), Ecology of Marine Plankton (ECOMAP) Team, Station Biologique de Roscoff (SBR), 29680, Roscoff, France
| | - Christophe Six
- Sorbonne Université, Centre National de la Recherche Scientifique, UMR 7144 Adaptation et Diversité en Milieu Marin (AD2M), Ecology of Marine Plankton (ECOMAP) Team, Station Biologique de Roscoff (SBR), 29680, Roscoff, France
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8
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Partensky F, Mella-Flores D, Six C, Garczarek L, Czjzek M, Marie D, Kotabová E, Felcmanová K, Prášil O. Comparison of photosynthetic performances of marine picocyanobacteria with different configurations of the oxygen-evolving complex. Photosynth Res 2018; 138:57-71. [PMID: 29938315 DOI: 10.1007/s11120-018-0539-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Accepted: 06/20/2018] [Indexed: 06/08/2023]
Abstract
The extrinsic PsbU and PsbV proteins are known to play a critical role in stabilizing the Mn4CaO5 cluster of the PSII oxygen-evolving complex (OEC). However, most isolates of the marine cyanobacterium Prochlorococcus naturally miss these proteins, even though they have kept the main OEC protein, PsbO. A structural homology model of the PSII of such a natural deletion mutant strain (P. marinus MED4) did not reveal any obvious compensation mechanism for this lack. To assess the physiological consequences of this unusual OEC, we compared oxygen evolution between Prochlorococcus strains missing psbU and psbV (PCC 9511 and SS120) and two marine strains possessing these genes (Prochlorococcus sp. MIT9313 and Synechococcus sp. WH7803). While the low light-adapted strain SS120 exhibited the lowest maximal O2 evolution rates (Pmax per divinyl-chlorophyll a, per cell or per photosystem II) of all four strains, the high light-adapted strain PCC 9511 displayed even higher PChlmax and PPSIImax at high irradiance than Synechococcus sp. WH7803. Furthermore, thermoluminescence glow curves did not show any alteration in the B-band shape or peak position that could be related to the lack of these extrinsic proteins. This suggests an efficient functional adaptation of the OEC in these natural deletion mutants, in which PsbO alone is seemingly sufficient to ensure proper oxygen evolution. Our study also showed that Prochlorococcus strains exhibit negative net O2 evolution rates at the low irradiances encountered in minimum oxygen zones, possibly explaining the very low O2 concentrations measured in these environments, where Prochlorococcus is the dominant oxyphototroph.
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Affiliation(s)
- Frédéric Partensky
- Sorbonne Université, Station Biologique, CS 90074, 29688, Roscoff cedex, France.
- CNRS UMR 7144, Station Biologique, CS 90074, 29680, Roscoff, France.
| | - Daniella Mella-Flores
- Sorbonne Université, Station Biologique, CS 90074, 29688, Roscoff cedex, France
- CNRS UMR 7144, Station Biologique, CS 90074, 29680, Roscoff, France
- Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
- Center of Applied Ecology and Sustainability (CAPES-UC), Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Christophe Six
- Sorbonne Université, Station Biologique, CS 90074, 29688, Roscoff cedex, France
- CNRS UMR 7144, Station Biologique, CS 90074, 29680, Roscoff, France
| | - Laurence Garczarek
- Sorbonne Université, Station Biologique, CS 90074, 29688, Roscoff cedex, France
- CNRS UMR 7144, Station Biologique, CS 90074, 29680, Roscoff, France
| | - Mirjam Czjzek
- Sorbonne Université, Station Biologique, CS 90074, 29688, Roscoff cedex, France
- CNRS UMR 8227, Marine Glycobiology Group, Station Biologique, CS 90074, 29680, Roscoff, France
| | - Dominique Marie
- Sorbonne Université, Station Biologique, CS 90074, 29688, Roscoff cedex, France
- CNRS UMR 7144, Station Biologique, CS 90074, 29680, Roscoff, France
| | - Eva Kotabová
- Laboratory of Photosynthesis, Institute of Microbiology, MBU AVČR, Opatovický mlýn, 37981, Třeboň, Czech Republic
| | - Kristina Felcmanová
- Laboratory of Photosynthesis, Institute of Microbiology, MBU AVČR, Opatovický mlýn, 37981, Třeboň, Czech Republic
- Faculty of Sciences, University of South Bohemia, Branišovská, 37005, České Budějovice, Czech Republic
| | - Ondřej Prášil
- Laboratory of Photosynthesis, Institute of Microbiology, MBU AVČR, Opatovický mlýn, 37981, Třeboň, Czech Republic
- Faculty of Sciences, University of South Bohemia, Branišovská, 37005, České Budějovice, Czech Republic
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9
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Zhong KX, Suttle CA, Baudoux AC, Derelle E, Colombet J, Cho A, Caleta J, Six C, Jacquet S. A New Freshwater Cyanosiphovirus Harboring Integrase. Front Microbiol 2018; 9:2204. [PMID: 30283423 PMCID: PMC6157547 DOI: 10.3389/fmicb.2018.02204] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Accepted: 08/29/2018] [Indexed: 11/13/2022] Open
Abstract
Pelagic cyanobacteria are key players in the functioning of aquatic ecosystems, and their viruses (cyanophages) potentially affect the abundance and composition of cyanobacterial communities. Yet, there are few well-described freshwater cyanophages relative to their marine counterparts, and in general, few cyanosiphoviruses (family Siphoviridae) have been characterized, limiting our understanding of the biology and the ecology of this prominent group of viruses. Here, we characterize S-LBS1, a freshwater siphovirus lytic to a phycoerythrin-rich Synechococcus isolate (Strain TCC793). S-LBS1 has a narrow host range, a burst size of ∼400 and a relatively long infecting step before cell lysis occurs. It has a dsDNA 34,641 bp genome with putative genes for structure, DNA packing, lysis, replication, host interactions, DNA repair and metabolism. S-LBS1 is similar in genome size, genome architecture, and gene content, to previously described marine siphoviruses also infecting PE-rich Synechococcus, e.g., S-CBS1 and S-CBS3. However, unlike other Synechococcus phages, S-LBS1 encodes an integrase, suggesting its ability to establish lysogenic relationships with its host. Sequence recruitment from viral metagenomic data showed that S-LBS1-like viruses are diversely present in a wide range of aquatic environments, emphasizing their potential importance in controlling and structuring Synechococcus populations. A comparative analysis with 16 available sequenced cyanosiphoviruses reveals the absence of core genes within the genomes, suggesting high degree of genetic variability in siphoviruses infecting cyanobacteria. It is likely that cyanosiphoviruses have evolved as distinct evolutionary lineages and that adaptive co-evolution occurred between these viruses and their hosts (i.e., Synechococcus, Prochlorococcus, Nodularia, and Acaryochloris), constituting an important driving force for such phage diversification.
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Affiliation(s)
- Kevin Xu Zhong
- INRA, UMR 042 CARRTEL, Thonon-les-Bains, France.,Department of Earth, Ocean, and Atmospheric Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Curtis A Suttle
- Department of Earth, Ocean, and Atmospheric Sciences, University of British Columbia, Vancouver, BC, Canada.,Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, Canada.,Department of Botany, Institute for Oceans and Fisheries, University of British Columbia, Vancouver, BC, Canada
| | - Anne-Claire Baudoux
- Sorbonne Universités UPMC Paris 06, CNRS, UMR7144 Adaptation et Diversité en Milieu Marin, Station Biologique de Roscoff, Roscoff, France
| | - Evelyne Derelle
- Integrative Marine Biology Laboratory (BIOM), CNRS UMR7232, Sorbonne Universities, Banyuls-sur-Mer, France
| | - Jonathan Colombet
- CNRS, Université Blaise Pascal, UMR 6023, Laboratory of Microorganismes, Aubière, France
| | - Anna Cho
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, Canada
| | - Jessica Caleta
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, Canada
| | - Christophe Six
- Sorbonne Universités UPMC Paris 06, CNRS, UMR7144 Adaptation et Diversité en Milieu Marin, Station Biologique de Roscoff, Roscoff, France
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10
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Demory D, Baudoux AC, Monier A, Simon N, Six C, Ge P, Rigaut-Jalabert F, Marie D, Sciandra A, Bernard O, Rabouille S. Picoeukaryotes of the Micromonas genus: sentinels of a warming ocean. ISME J 2018; 13:132-146. [PMID: 30116039 DOI: 10.1038/s41396-018-0248-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Revised: 05/15/2018] [Accepted: 06/11/2018] [Indexed: 11/09/2022]
Abstract
Photosynthetic picoeukaryotesx in the genus Micromonas show among the widest latitudinal distributions on Earth, experiencing large thermal gradients from poles to tropics. Micromonas comprises at least four different species often found in sympatry. While such ubiquity might suggest a wide thermal niche, the temperature response of the different strains is still unexplored, leaving many questions as for their ecological success over such diverse ecosystems. Using combined experiments and theory, we characterize the thermal response of eleven Micromonas strains belonging to four species. We demonstrate that the variety of specific responses to temperature in the Micromonas genus makes this environmental factor an ideal marker to describe its global distribution and diversity. We then propose a diversity model for the genus Micromonas, which proves to be representative of the whole phytoplankton diversity. This prominent primary producer is therefore a sentinel organism of phytoplankton diversity at the global scale. We use the diversity within Micromonas to anticipate the potential impact of global warming on oceanic phytoplankton. We develop a dynamic, adaptive model and run forecast simulations, exploring a range of adaptation time scales, to probe the likely responses to climate change. Results stress how biodiversity erosion depends on the ability of organisms to adapt rapidly to temperature increase.
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Affiliation(s)
- David Demory
- School of Biology, Georgia Institute of Technology, Atlanta, GA, USA. .,Sorbonne University, UPMC Univ Paris 06, INSU-CNRS, UMR 7093, Laboratoire Océanographique de Villefranche, 181 Chemin du Lazaret, 06230, Villefranche-sur-mer, France. .,University of Côte d'Azur, INRIA, BIOCORE team, BP93, 06902, Sophia-Antipolis Cedex, France.
| | - Anne-Claire Baudoux
- Sorbonne University, UPMC Univ Paris 06, CNRS, UMR 7144, Station Biologique de Roscoff, 29680, Roscoff, France
| | - Adam Monier
- Biosciences, University of Exeter, Exeter, UK
| | - Nathalie Simon
- Sorbonne University, UPMC Univ Paris 06, CNRS, UMR 7144, Station Biologique de Roscoff, 29680, Roscoff, France
| | - Christophe Six
- Sorbonne University, UPMC Univ Paris 06, CNRS, UMR 7144, Station Biologique de Roscoff, 29680, Roscoff, France
| | - Pei Ge
- Sorbonne University, UPMC Univ Paris 06, CNRS, UMR 7144, Station Biologique de Roscoff, 29680, Roscoff, France
| | - Fabienne Rigaut-Jalabert
- Sorbonne University, UPMC Univ Paris 06, CNRS, Fédération de Recherche FR2424, Station Biologique de Roscoff, 29680, Roscoff, France
| | - Dominique Marie
- Sorbonne University, UPMC Univ Paris 06, CNRS, UMR 7144, Station Biologique de Roscoff, 29680, Roscoff, France
| | - Antoine Sciandra
- Sorbonne University, UPMC Univ Paris 06, INSU-CNRS, UMR 7093, Laboratoire Océanographique de Villefranche, 181 Chemin du Lazaret, 06230, Villefranche-sur-mer, France
| | - Olivier Bernard
- University of Côte d'Azur, INRIA, BIOCORE team, BP93, 06902, Sophia-Antipolis Cedex, France.
| | - Sophie Rabouille
- Sorbonne University, UPMC Univ Paris 06, INSU-CNRS, UMR 7093, Laboratoire Océanographique de Villefranche, 181 Chemin du Lazaret, 06230, Villefranche-sur-mer, France.
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11
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Pittera J, Jouhet J, Breton S, Garczarek L, Partensky F, Maréchal É, Nguyen NA, Doré H, Ratin M, Pitt FD, Scanlan DJ, Six C. Thermoacclimation and genome adaptation of the membrane lipidome in marine Synechococcus. Environ Microbiol 2017; 20:612-631. [PMID: 29124854 DOI: 10.1111/1462-2920.13985] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Revised: 10/20/2017] [Accepted: 11/02/2017] [Indexed: 12/01/2022]
Abstract
The marine cyanobacteria of the genus Synechococcus are important primary producers, displaying a wide latitudinal distribution that is underpinned by diversification into temperature ecotypes. The physiological basis underlying these ecotypes is poorly known. In many organisms, regulation of membrane fluidity is crucial for acclimating to variations in temperature. Here, we reveal the detailed composition of the membrane lipidome of the model strain Synechococcus sp. WH7803 and its response to temperature variation. Unlike freshwater strains, membranes are almost devoid of C18, mainly containing C14 and C16 chains with no more than two unsaturations. In response to cold, we observed a rarely observed process of acyl chain shortening that likely induces membrane thinning, along with specific desaturation activities. Both of these mechanisms likely regulate membrane fluidity, facilitating the maintenance of efficient photosynthetic activity. A comprehensive examination of 53 Synechococcus genomes revealed clade-specific gene sets regulating membrane lipids. In particular, the genes encoding desaturase enzymes, which is a key to the temperature stress response, appeared to be temperature ecotype-specific, with some of them originating from lateral transfers. Our study suggests that regulation of membrane fluidity has been among the important adaptation processes for the colonization of different thermal niches by marine Synechococcus.
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Affiliation(s)
- Justine Pittera
- Marine Phototrophic Prokaryotes group, Station Biologique, Place Georges Teissier, Sorbonne Universités, Université Pierre and Marie Curie (Paris 06) and Centre National de la Recherche Scientifique, UMR 7144, 29688 Roscoff cedex, CS 90074, France
| | - Juliette Jouhet
- Institut de Biosciences et Biotechnologies de Grenoble, CEA Grenoble, Laboratoire de Physiologie Cellulaire et Végétale, UMR 5168 Centre National de la Recherche Scientifique, Commissariat à l'Energie Atomique, Institut National de la Recherche Agronomique, Université Grenoble Alpes, 38054 Grenoble cedex 9, France
| | - Solène Breton
- Marine Phototrophic Prokaryotes group, Station Biologique, Place Georges Teissier, Sorbonne Universités, Université Pierre and Marie Curie (Paris 06) and Centre National de la Recherche Scientifique, UMR 7144, 29688 Roscoff cedex, CS 90074, France
| | - Laurence Garczarek
- Marine Phototrophic Prokaryotes group, Station Biologique, Place Georges Teissier, Sorbonne Universités, Université Pierre and Marie Curie (Paris 06) and Centre National de la Recherche Scientifique, UMR 7144, 29688 Roscoff cedex, CS 90074, France
| | - Frédéric Partensky
- Marine Phototrophic Prokaryotes group, Station Biologique, Place Georges Teissier, Sorbonne Universités, Université Pierre and Marie Curie (Paris 06) and Centre National de la Recherche Scientifique, UMR 7144, 29688 Roscoff cedex, CS 90074, France
| | - Éric Maréchal
- Institut de Biosciences et Biotechnologies de Grenoble, CEA Grenoble, Laboratoire de Physiologie Cellulaire et Végétale, UMR 5168 Centre National de la Recherche Scientifique, Commissariat à l'Energie Atomique, Institut National de la Recherche Agronomique, Université Grenoble Alpes, 38054 Grenoble cedex 9, France
| | - Ngoc A Nguyen
- Marine Phototrophic Prokaryotes group, Station Biologique, Place Georges Teissier, Sorbonne Universités, Université Pierre and Marie Curie (Paris 06) and Centre National de la Recherche Scientifique, UMR 7144, 29688 Roscoff cedex, CS 90074, France
| | - Hugo Doré
- Marine Phototrophic Prokaryotes group, Station Biologique, Place Georges Teissier, Sorbonne Universités, Université Pierre and Marie Curie (Paris 06) and Centre National de la Recherche Scientifique, UMR 7144, 29688 Roscoff cedex, CS 90074, France
| | - Morgane Ratin
- Marine Phototrophic Prokaryotes group, Station Biologique, Place Georges Teissier, Sorbonne Universités, Université Pierre and Marie Curie (Paris 06) and Centre National de la Recherche Scientifique, UMR 7144, 29688 Roscoff cedex, CS 90074, France
| | - Frances D Pitt
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK
| | - David J Scanlan
- School of Life Sciences, University of Warwick, Coventry CV4 7AL, UK
| | - Christophe Six
- Marine Phototrophic Prokaryotes group, Station Biologique, Place Georges Teissier, Sorbonne Universités, Université Pierre and Marie Curie (Paris 06) and Centre National de la Recherche Scientifique, UMR 7144, 29688 Roscoff cedex, CS 90074, France
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12
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Simon N, Foulon E, Grulois D, Six C, Desdevises Y, Latimier M, Le Gall F, Tragin M, Houdan A, Derelle E, Jouenne F, Marie D, Le Panse S, Vaulot D, Marin B. Revision of the Genus Micromonas Manton et Parke (Chlorophyta, Mamiellophyceae), of the Type Species M. pusilla (Butcher) Manton & Parke and of the Species M. commoda van Baren, Bachy and Worden and Description of Two New Species Based on the Genetic and Phenotypic Characterization of Cultured Isolates. Protist 2017; 168:612-635. [PMID: 29028580 DOI: 10.1016/j.protis.2017.09.002] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Revised: 08/31/2017] [Accepted: 09/06/2017] [Indexed: 11/30/2022]
Abstract
The green picoalgal genus Micromonas is broadly distributed in estuaries, coastal marine habitats and open oceans, from the equator to the poles. Phylogenetic, ecological and genomic analyses of culture strains and natural populations have suggested that this cosmopolitan genus is composed of several cryptic species corresponding to genetic lineages. We performed a detailed analysis of variations in morphology, pigment content, and sequences of the nuclear-encoded small-subunit rRNA gene and the second internal transcribed spacer (ITS2) from strains isolated worldwide. A new morphological feature of the genus, the presence of tip hairs at the extremity of the hair point, was discovered and subtle differences in hair point length were detected between clades. Clear non-homoplasious synapomorphies were identified in the small-subunit rRNA gene and ITS2 spacer sequences of five genetic lineages. These findings lead us to provide emended descriptions of the genus Micromonas, of the type species M. pusilla, and of the recently described species M. commoda, as well as to describe 2 new species, M. bravo and M. polaris. By clarifying the status of the genetic lineages identified within Micromonas, these formal descriptions will facilitate further interpretations of large-scale analyses investigating ecological trends in time and space for this widespread picoplankter.
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Affiliation(s)
- Nathalie Simon
- Sorbonne Universités, Université Pierre et Marie Curie - Paris 06 and Centre National de la recherche Scientifique (CNRS), UMR 7144, Laboratoire Adaptation et Diversité en Milieu Marin, Station Biologique de Roscoff, Place Georges Teissier, 29680 Roscoff, France.
| | - Elodie Foulon
- Sorbonne Universités, Université Pierre et Marie Curie - Paris 06 and Centre National de la recherche Scientifique (CNRS), UMR 7144, Laboratoire Adaptation et Diversité en Milieu Marin, Station Biologique de Roscoff, Place Georges Teissier, 29680 Roscoff, France
| | - Daphné Grulois
- Sorbonne Universités, Université Pierre et Marie Curie - Paris 06 and Centre National de la recherche Scientifique (CNRS), UMR 7144, Laboratoire Adaptation et Diversité en Milieu Marin, Station Biologique de Roscoff, Place Georges Teissier, 29680 Roscoff, France
| | - Christophe Six
- Sorbonne Universités, Université Pierre et Marie Curie - Paris 06 and Centre National de la recherche Scientifique (CNRS), UMR 7144, Laboratoire Adaptation et Diversité en Milieu Marin, Station Biologique de Roscoff, Place Georges Teissier, 29680 Roscoff, France
| | - Yves Desdevises
- Sorbonne Universités, Université Pierre et Marie Curie - Paris 06 and Centre National de la recherche Scientifique (CNRS), UMR 7232, BIOM, Observatoire Océanologique, 66650 Banyuls/Mer, France
| | - Marie Latimier
- Sorbonne Universités, Université Pierre et Marie Curie - Paris 06 and Centre National de la recherche Scientifique (CNRS), UMR 7144, Laboratoire Adaptation et Diversité en Milieu Marin, Station Biologique de Roscoff, Place Georges Teissier, 29680 Roscoff, France
| | - Florence Le Gall
- Sorbonne Universités, Université Pierre et Marie Curie - Paris 06 and Centre National de la recherche Scientifique (CNRS), UMR 7144, Laboratoire Adaptation et Diversité en Milieu Marin, Station Biologique de Roscoff, Place Georges Teissier, 29680 Roscoff, France
| | - Margot Tragin
- Sorbonne Universités, Université Pierre et Marie Curie - Paris 06 and Centre National de la recherche Scientifique (CNRS), UMR 7144, Laboratoire Adaptation et Diversité en Milieu Marin, Station Biologique de Roscoff, Place Georges Teissier, 29680 Roscoff, France
| | - Aude Houdan
- Sorbonne Universités, Université Pierre et Marie Curie - Paris 06 and Centre National de la recherche Scientifique (CNRS), UMR 7144, Laboratoire Adaptation et Diversité en Milieu Marin, Station Biologique de Roscoff, Place Georges Teissier, 29680 Roscoff, France
| | - Evelyne Derelle
- Sorbonne Universités, Université Pierre et Marie Curie - Paris 06 and Centre National de la recherche Scientifique (CNRS), UMR 7232, BIOM, Observatoire Océanologique, 66650 Banyuls/Mer, France
| | - Fabien Jouenne
- Sorbonne Universités, Université Pierre et Marie Curie - Paris 06 and Centre National de la recherche Scientifique (CNRS), UMR 7144, Laboratoire Adaptation et Diversité en Milieu Marin, Station Biologique de Roscoff, Place Georges Teissier, 29680 Roscoff, France
| | - Dominique Marie
- Sorbonne Universités, Université Pierre et Marie Curie - Paris 06 and Centre National de la recherche Scientifique (CNRS), UMR 7144, Laboratoire Adaptation et Diversité en Milieu Marin, Station Biologique de Roscoff, Place Georges Teissier, 29680 Roscoff, France
| | - Sophie Le Panse
- Sorbonne Universités, Université Pierre et Marie Curie - Paris 06 and Centre National de la recherche Scientifique (CNRS), FR2424, Imaging Core Facility, Station Biologique de Roscoff, Place Georges Teissier, 29680 Roscoff, France
| | - Daniel Vaulot
- Sorbonne Universités, Université Pierre et Marie Curie - Paris 06 and Centre National de la recherche Scientifique (CNRS), UMR 7144, Laboratoire Adaptation et Diversité en Milieu Marin, Station Biologique de Roscoff, Place Georges Teissier, 29680 Roscoff, France
| | - Birger Marin
- Botanisches Institut, Biozentrum Köln, Universität zu Köln, Zülpicher Str. 47b, 50674 Köln, Germany
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13
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Botebol H, Lelandais G, Six C, Lesuisse E, Meng A, Bittner L, Lecrom S, Sutak R, Lozano JC, Schatt P, Vergé V, Blain S, Bouget FY. Acclimation of a low iron adapted Ostreococcus strain to iron limitation through cell biomass lowering. Sci Rep 2017; 7:327. [PMID: 28336917 PMCID: PMC5428002 DOI: 10.1038/s41598-017-00216-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Accepted: 02/14/2017] [Indexed: 11/17/2022] Open
Abstract
Iron is an essential micronutrient involved in many biological processes and is often limiting for primary production in large regions of the World Ocean. Metagenomic and physiological studies have identified clades or ecotypes of marine phytoplankton that are specialized in iron depleted ecological niches. Although less studied, eukaryotic picophytoplankton does contribute significantly to primary production and carbon transfer to higher trophic levels. In particular, metagenomic studies of the green picoalga Ostreococcus have revealed the occurrence of two main clades distributed along coast-offshore gradients, suggesting niche partitioning in different nutrient regimes. Here, we present a study of the response to iron limitation of four Ostreococcus strains isolated from contrasted environments. Whereas the strains isolated in nutrient-rich waters showed high iron requirements, the oceanic strains could cope with lower iron concentrations. The RCC802 strain, in particular, was able to maintain high growth rate at low iron levels. Together physiological and transcriptomic data indicate that the competitiveness of RCC802 under iron limitation is related to a lowering of iron needs though a reduction of the photosynthetic machinery and of protein content, rather than to cell size reduction. Our results overall suggest that iron is one of the factors driving the differentiation of physiologically specialized Ostreococcus strains in the ocean.
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Affiliation(s)
- Hugo Botebol
- Sorbonne Universités, Université Pierre et Marie Curie (Paris 06) & Centre National pour la Recherche Scientifique CNRS, UMR 7621, Laboratoire d'Océanographie Microbienne, Observatoire Océanologique, F-66650, Banyuls/mer, France
| | - Gaelle Lelandais
- Université Paris Diderot (Paris 07), Centre National de la Recherche Scientifique, Institut Jacques Monod, F-75013, Paris, France
| | - Christophe Six
- Sorbonne Universités, Université Pierre et Marie Curie (Paris 06) & Centre National pour la Recherche Scientifique, UMR 7144, Adaptation et Diversité en Milieu Marin, Equipe Marine Phototrophic Prokaryotes, Station Biologique de Roscoff, 29680, Roscoff Cedex, France
| | - Emmanuel Lesuisse
- Université Paris Diderot (Paris 07), Centre National de la Recherche Scientifique, Institut Jacques Monod, F-75013, Paris, France
| | - Arnaud Meng
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, Institut de Biologie Paris-Seine (IBPS), Evolution Paris Seine, F-75005, Paris, France
| | - Lucie Bittner
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, Institut de Biologie Paris-Seine (IBPS), Evolution Paris Seine, F-75005, Paris, France
| | - Stéphane Lecrom
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, Institut de Biologie Paris-Seine (IBPS), Evolution Paris Seine, F-75005, Paris, France
| | - Robert Sutak
- Department of Parasitology, Faculty of Science, Charles University, 12844, Prague, Czech Republic
| | - Jean-Claude Lozano
- Sorbonne Universités, Université Pierre et Marie Curie (Paris 06) & Centre National pour la Recherche Scientifique CNRS, UMR 7621, Laboratoire d'Océanographie Microbienne, Observatoire Océanologique, F-66650, Banyuls/mer, France
| | - Philippe Schatt
- Sorbonne Universités, Université Pierre et Marie Curie (Paris 06) & Centre National pour la Recherche Scientifique CNRS, UMR 7621, Laboratoire d'Océanographie Microbienne, Observatoire Océanologique, F-66650, Banyuls/mer, France
| | - Valérie Vergé
- Sorbonne Universités, Université Pierre et Marie Curie (Paris 06) & Centre National pour la Recherche Scientifique CNRS, UMR 7621, Laboratoire d'Océanographie Microbienne, Observatoire Océanologique, F-66650, Banyuls/mer, France
| | - Stéphane Blain
- Sorbonne Universités, Université Pierre et Marie Curie (Paris 06) & Centre National pour la Recherche Scientifique CNRS, UMR 7621, Laboratoire d'Océanographie Microbienne, Observatoire Océanologique, F-66650, Banyuls/mer, France.
| | - François-Yves Bouget
- Sorbonne Universités, Université Pierre et Marie Curie (Paris 06) & Centre National pour la Recherche Scientifique CNRS, UMR 7621, Laboratoire d'Océanographie Microbienne, Observatoire Océanologique, F-66650, Banyuls/mer, France.
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Demory D, Arsenieff L, Simon N, Six C, Rigaut-Jalabert F, Marie D, Ge P, Bigeard E, Jacquet S, Sciandra A, Bernard O, Rabouille S, Baudoux AC. Temperature is a key factor in Micromonas-virus interactions. ISME J 2017; 11:601-612. [PMID: 28085157 DOI: 10.1038/ismej.2016.160] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Revised: 09/30/2016] [Accepted: 10/07/2016] [Indexed: 11/09/2022]
Abstract
The genus Micromonas comprises phytoplankton that show among the widest latitudinal distributions on Earth, and members of this genus are recurrently infected by prasinoviruses in contrasted thermal ecosystems. In this study, we assessed how temperature influences the interplay between the main genetic clades of this prominent microalga and their viruses. The growth of three Micromonas strains (Mic-A, Mic-B, Mic-C) and the stability of their respective lytic viruses (MicV-A, MicV-B, MicV-C) were measured over a thermal range of 4-32.5 °C. Similar growth temperature optima (Topt) were predicted for all three hosts but Mic-B exhibited a broader thermal tolerance than Mic-A and Mic-C, suggesting distinct thermoacclimation strategies. Similarly, the MicV-C virus displayed a remarkable thermal stability compared with MicV-A and MicV-B. Despite these divergences, infection dynamics showed that temperatures below Topt lengthened lytic cycle kinetics and reduced viral yield and, notably, that infection at temperatures above Topt did not usually result in cell lysis. Two mechanisms operated depending on the temperature and the biological system. Hosts either prevented the production of viral progeny or maintained their ability to produce virions with no apparent cell lysis, pointing to a possible switch in the viral life strategy. Hence, temperature changes critically affect the outcome of Micromonas infection and have implications for ocean biogeochemistry and evolution.
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Affiliation(s)
- David Demory
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, Villefranche/mer, France.,BIOCORE-INRIA, BP93, Sophia-Antipolis Cedex, France
| | - Laure Arsenieff
- Sorbonne Universités, UPMC Univ Pierre et Marie Curie (Paris 06), CNRS, Adaptation et Diversité en Milieu Marin UMR7144, Station Biologique de Roscoff, Roscoff, France
| | - Nathalie Simon
- Sorbonne Universités, UPMC Univ Pierre et Marie Curie (Paris 06), CNRS, Adaptation et Diversité en Milieu Marin UMR7144, Station Biologique de Roscoff, Roscoff, France
| | - Christophe Six
- Sorbonne Universités, UPMC Univ Pierre et Marie Curie (Paris 06), CNRS, Adaptation et Diversité en Milieu Marin UMR7144, Station Biologique de Roscoff, Roscoff, France
| | - Fabienne Rigaut-Jalabert
- Sorbonne Universités, UPMC Univ Pierre et Marie Curie (Paris 06), CNRS, Fédération de Recherche FR2424, Station Biologique de Roscoff, Roscoff, France
| | - Dominique Marie
- Sorbonne Universités, UPMC Univ Pierre et Marie Curie (Paris 06), CNRS, Adaptation et Diversité en Milieu Marin UMR7144, Station Biologique de Roscoff, Roscoff, France
| | - Pei Ge
- Sorbonne Universités, UPMC Univ Pierre et Marie Curie (Paris 06), CNRS, Adaptation et Diversité en Milieu Marin UMR7144, Station Biologique de Roscoff, Roscoff, France
| | - Estelle Bigeard
- Sorbonne Universités, UPMC Univ Pierre et Marie Curie (Paris 06), CNRS, Adaptation et Diversité en Milieu Marin UMR7144, Station Biologique de Roscoff, Roscoff, France
| | | | - Antoine Sciandra
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, Villefranche/mer, France
| | | | - Sophie Rabouille
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, Villefranche/mer, France
| | - Anne-Claire Baudoux
- Sorbonne Universités, UPMC Univ Pierre et Marie Curie (Paris 06), CNRS, Adaptation et Diversité en Milieu Marin UMR7144, Station Biologique de Roscoff, Roscoff, France
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Giron S, Dassonville F, Galey C, Aboukais S, Ambert-Balay K, Six C. Investigation d’une épidémie massive de gastro-entérites aiguës après une course à obstacles en juin 2015, Alpes-Maritimes, France. Rev Epidemiol Sante Publique 2016. [DOI: 10.1016/j.respe.2016.06.040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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16
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Septfons A, Leparc-Goffart I, Couturier E, Franke F, Deniau J, Balestier A, Guinard A, Heuzé G, Liebert AH, Mailles A, Ndong JR, Poujol I, Raguet S, Rousseau C, Saidouni-Oulebsir A, Six C, Subiros M, Servas V, Terrien E, Tillaut H, Viriot D, Watrin M, Wyndels K, Noel H, Paty MC, De Valk H. Travel-associated and autochthonous Zika virus infection in mainland France, 1 January to 15 July 2016. Euro Surveill 2016; 21:30315. [PMID: 27542120 PMCID: PMC4998503 DOI: 10.2807/1560-7917.es.2016.21.32.30315] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Accepted: 08/11/2016] [Indexed: 01/07/2023] Open
Abstract
During summer 2016, all the conditions for local mosquito-borne transmission of Zika virus (ZIKV) are met in mainland France: a competent vector, Aedes albopictus, a large number of travellers returning from ZIKV-affected areas, and an immunologically naive population. From 1 January to 15 July 2016, 625 persons with evidence of recent ZIKV infection were reported in mainland France. We describe the surveillance system in place and control measures implemented to reduce the risk of infection.
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Affiliation(s)
- A Septfons
- Santé publique France, French national public health agency, Saint-Maurice, France
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Lavaud J, Six C, Campbell DA. Photosystem II repair in marine diatoms with contrasting photophysiologies. Photosynth Res 2016; 127:189-99. [PMID: 26156125 DOI: 10.1007/s11120-015-0172-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Accepted: 06/25/2015] [Indexed: 05/23/2023]
Abstract
Skeletonema costatum and Phaeodactylum tricornutum are model marine diatoms with differing strategies for non-photochemical dissipation of excess excitation energy within photosystem II (PSII). We showed that S. costatum, with connectivity across the pigment bed serving PSII, and limited capacity for induction of sustained non-photochemical quenching (NPQ), maintained a large ratio of [PSII(Total)]/[PSII(Active)] to buffer against fluctuations in light intensity. In contrast, P. tricornutum, with a larger capacity to induce sustained NPQ, could maintain a lower [PSII(Total)]/[PSII(Active)]. Induction of NPQ was correlated with an active PSII repair cycle in both species, and inhibition of chloroplastic protein synthesis with lincomycin leads to run away over-excitation of remaining PSII(Active), particularly in S. costatum. We discuss these distinctions in relation to the differing capacities, induction and relaxation rates for NPQ, and as strain adaptations to the differential light regimes of their originating habitats. The present work further confirms the important role for the light-dependent fast regulation of photochemistry by NPQ interacting with PSII repair cycle capacity in the ecophysiology of both pennate and centric diatoms.
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Affiliation(s)
- Johann Lavaud
- UMRi 7266 'LIENSs', Institut du Littoral et de l'Environnement (ILE), CNRS-University of La Rochelle, 2 rue Olympe de Gouges, 17000, La Rochelle Cedex, France.
| | - Christophe Six
- Department of Biology, Mount Allison University, Sackville, NB E4L 1G7, Canada
- UMR 7144 'Adaptation et Diversité en Milieu Marin', 'Marine Phototrophic Prokaryotes' group, Centre National pour la Recherche Scientifique (CNRS), Station Biologique de Roscoff, Place George Teissier, 29680, Roscoff, France
- UMR 7144 'Adaptation et Diversité en Milieu Marin', 'Marine Phototrophic Prokaryotes' group, Université Pierre et Marie Curie (Paris 06), Station Biologique de Roscoff, Place George Teissier, 29680, Roscoff, France
| | - Douglas A Campbell
- Department of Biology, Mount Allison University, Sackville, NB E4L 1G7, Canada
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Succo T, Baldasseroni L, Charlet F, Delarozière JC, Six C, Charrel R. Dispositif de diagnostic et de gestion du risque d’épidémie de grippe chez les personnes âgées en Ehpad en région Paca, saisons grippales 2012–2013 et 2013–2014. Rev Epidemiol Sante Publique 2014. [PMCID: PMC7130926 DOI: 10.1016/j.respe.2014.06.204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Introduction Depuis l’hiver 2012–2013, l’Agence régionale de santé (ARS) Paca dote les établissements d’hébergement pour personnes âgées dépendantes (Ehpad) de la région d’écouvillons naso-pharyngés pour réaliser des tests rapides à orientation diagnostique (TROD) grippe. Une étude pluriannuelle a été initiée pour mieux cibler les virus circulant en Ehpad. Méthode En cas de grippe suspectée chez un résident, les Ehpad collectaient des données cliniques et un TROD était analysé par un laboratoire. Les prélèvements étaient ensuite analysés par RT-PCR multiplex au CHU de Marseille pour vérification des résultats et recherche d’autres virus (adénovirus, entérovirus [EV], parainfluenzavirus [PIV], influenzavirus, virus respiratoire syncitial [VRS], métapneumovirus [hMPV], rhinovirus et coronavirus [CoV]). Résultats Durant la première saison, 62 prélèvements ont été analysés. L’âge moyen des cas était de 87 ans et 94 % étaient vaccinés contre la grippe saisonnière. Les délais moyen et médian de prélèvement étaient respectivement de 1,5 et 1 jour. Les TROD grippe étaient positifs dans 23 % des prélèvements. Les RT-PCR ont identifié un virus pour 52 % des prélèvements dont 55 % de virus grippal. Les autres virus (45 %) étaient des EV, PIV, VRS, hMPV et CoV. Discussion La RT-PCR a permis de doubler le nombre de résultats positifs, tous virus confondus, 50 % des prélèvements étant positifs pour un des virus recherchés. Le délai maximal de prélèvement de 48 h nécessaire à l’interprétation correcte des TROD était respecté. Peu de prélèvements ont été collectés sur la saison 2013–2014, du fait d’une épidémie grippale d’intensité limitée chez les personnes âgées, et les résultats de la surveillance seront disponibles au printemps. Cette étude sera renouvelée sur plusieurs années.
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Korhonen T, Neveu A, Succo T, Armengaud A, Six C, Malfait P. Estimation de la couverture vaccinale anti-rougeoleuse parmi les internes de la faculté de médecine de l’Université d’Aix-Marseille et identification des raisons de vaccination et de non-vaccination, mars 2013. Rev Epidemiol Sante Publique 2014. [DOI: 10.1016/j.respe.2014.06.106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
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20
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Succo T, Braunstein D, Desmons S, Sampol P, Guisoe N, Six C. Foyer de coqueluche dans un établissement d’hébergement pour personnes âgées dépendantes en 2013, Bouches-du-Rhône, France. Rev Epidemiol Sante Publique 2014. [DOI: 10.1016/j.respe.2014.06.124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
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21
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Six C, Prat C, Jeannin C, Roux N, Deniau J, Noel H. Survenue d’un cas autochtone de dengue dans les Bouches-du-Rhône, région Provence-Alpes-Côte d’Azur, octobre 2013. Rev Epidemiol Sante Publique 2014. [DOI: 10.1016/j.respe.2014.06.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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22
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Paty MC, Six C, Charlet F, Heuzé G, Cochet A, Wiegandt A, Chappert JL, Dejour-Salamanca D, Guinard A, Soler P, Servas V, Vivier-Darrigol M, Ledrans M, Debruyne M, Schaal O, Jeannin C, Helynck B, Leparc-Goffart I, Coignard B. Large number of imported chikungunya cases in mainland France, 2014: a challenge for surveillance and response. Euro Surveill 2014; 19:20856. [DOI: 10.2807/1560-7917.es2014.19.28.20856] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
During the summer of 2014, all the pre-requisites for autochthonous transmission of chikungunya virus are present in southern France: a competent vector, Aedes albopictus, and a large number of travellers returning from the French Caribbean islands where an outbreak is occurring. We describe the system implemented for the surveillance of chikungunya and dengue in mainland France. From 2 May to 4 July 2014, there were 126 laboratory-confirmed imported chikungunya cases in mainland France.
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Affiliation(s)
- M C Paty
- French Institute for Public Health Surveillance (Institut de Veille Sanitaire, InVS), Saint-Maurice, France
| | - C Six
- Regional office of the French Institute for Public Health Surveillance (Cire Sud), Marseille, France
| | - F Charlet
- Regional Health Agency (ARS) of Provence-Alpes-Côte d’Azur, Marseille, France
| | - G Heuzé
- Regional Health Agency (ARS) of Corsica, Ajaccio, France
| | - A Cochet
- Regional office of the French Institute for Public Health Surveillance (Cire Languedoc Roussillon), Montpellier, France
| | - A Wiegandt
- Regional Health Agency (ARS) of Languedoc Roussillon, Montpellier, France
| | - J L Chappert
- Regional office of the French Institute for Public Health Surveillance (Cire Rhône Alpes), Lyon, France
| | | | - A Guinard
- Regional office of the French Institute for Public Health Surveillance (Cire Midi Pyrénées), Toulouse, France
| | - P Soler
- Regional Health Agency (ARS) of Midi Pyrénées, Toulouse, France
| | - V Servas
- Regional office of the French Institute for Public Health Surveillance (Cire Aquitaine), Bordeaux, France
| | | | - M Ledrans
- Regional office of the French Institute for Public Health Surveillance (Cire Antilles Guyane), Fort-de-France, France
| | - M Debruyne
- Laboratoire Cerba, Saint-Ouen l’Aumône, France
| | - O Schaal
- Laboratoire Biomnis, Lyon, France
| | - C Jeannin
- EID: Public mosquito control agency, Montpellier, France
| | - B Helynck
- French Institute for Public Health Surveillance (Institut de Veille Sanitaire, InVS), Saint-Maurice, France
| | - I Leparc-Goffart
- Institut de Recherche Biomédicale des Armées, National Reference Laboratory for arboviruses, Marseille, France
| | - B Coignard
- French Institute for Public Health Surveillance (Institut de Veille Sanitaire, InVS), Saint-Maurice, France
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Van Bortel W, Dorleans F, Rosine J, Blateau A, Rousset D, Matheus S, Leparc-Goffart I, Flusin O, Prat C, Cesaire R, Najioullah F, Ardillon V, Balleydier E, Carvalho L, Lemaître A, Noel H, Servas V, Six C, Zurbaran M, Leon L, Guinard A, van den Kerkhof J, Henry M, Fanoy E, Braks M, Reimerink J, Swaan C, Georges R, Brooks L, Freedman J, Sudre B, Zeller H. Chikungunya outbreak in the Caribbean region, December 2013 to March 2014, and the significance for Europe. ACTA ACUST UNITED AC 2014; 19. [PMID: 24721539 DOI: 10.2807/1560-7917.es2014.19.13.20759] [Citation(s) in RCA: 154] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
On 6 December 2013, two laboratory-confirmed cases of chikungunya without a travel history were reported on the French part of the Caribbean island of Saint Martin, indicating the start of the first documented outbreak of chikungunya in the Americas. Since this report, the virus spread to several Caribbean islands and French Guiana, and between 6 December 2013 and 27 March 2014 more than 17,000 suspected and confirmed cases have been reported. Further spread and establishment of the disease in the Americas is likely, given the high number of people travelling between the affected and non-affected areas and the widespread occurrence of efficient vectors. Also, the likelihood of the introduction of the virus into Europe from the Americas and subsequent transmission should be considered especially in the context of the next mosquito season in Europe. Clinicians should be aware that, besides dengue, chikungunya should be carefully considered among travellers currently returning from the Caribbean region.
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Affiliation(s)
- W Van Bortel
- European Centre for Disease Prevention and Control, Stockholm, Sweden
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Pittera J, Humily F, Thorel M, Grulois D, Garczarek L, Six C. Connecting thermal physiology and latitudinal niche partitioning in marine Synechococcus. ISME J 2014; 8:1221-36. [PMID: 24401861 DOI: 10.1038/ismej.2013.228] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Revised: 11/15/2013] [Accepted: 11/16/2013] [Indexed: 01/05/2023]
Abstract
Marine Synechococcus cyanobacteria constitute a monophyletic group that displays a wide latitudinal distribution, ranging from the equator to the polar fronts. Whether these organisms are all physiologically adapted to stand a large temperature gradient or stenotherms with narrow growth temperature ranges has so far remained unexplored. We submitted a panel of six strains, isolated along a gradient of latitude in the North Atlantic Ocean, to long- and short-term variations of temperature. Upon a downward shift of temperature, the strains showed strikingly distinct resistance, seemingly related to their latitude of isolation, with tropical strains collapsing while northern strains were capable of growing. This behaviour was associated to differential photosynthetic performances. In the tropical strains, the rapid photosystem II inactivation and the decrease of the antioxydant β-carotene relative to chl a suggested a strong induction of oxidative stress. These different responses were related to the thermal preferenda of the strains. The northern strains could grow at 10 °C while the other strains preferred higher temperatures. In addition, we pointed out a correspondence between strain isolation temperature and phylogeny. In particular, clades I and IV laboratory strains were all collected in the coldest waters of the distribution area of marine Synechococus. We, however, show that clade I Synechococcus exhibit different levels of adaptation, which apparently reflect their location on the latitudinal temperature gradient. This study reveals the existence of lineages of marine Synechococcus physiologically specialised in different thermal niches, therefore suggesting the existence of temperature ecotypes within the marine Synechococcus radiation.
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Affiliation(s)
- Justine Pittera
- 1] University Pierre and Marie Curie (Paris 06), UMR 7144 Adaptation and Diversity in Marine Environments, Marine Phototrophic Procaryotes (MaPP) Team, Station Biologique de Roscoff, Place Georges Teissier, CS 90074, Roscoff cedex, France [2] Centre National de la Recherche Scientifique, UMR 7144 Adaptation and Diversity in Marine Environments, Oceanic Plankton Group, Station Biologique de Roscoff, Place Georges Teissier, CS 90074, Roscoff cedex, France
| | - Florian Humily
- 1] University Pierre and Marie Curie (Paris 06), UMR 7144 Adaptation and Diversity in Marine Environments, Marine Phototrophic Procaryotes (MaPP) Team, Station Biologique de Roscoff, Place Georges Teissier, CS 90074, Roscoff cedex, France [2] Centre National de la Recherche Scientifique, UMR 7144 Adaptation and Diversity in Marine Environments, Oceanic Plankton Group, Station Biologique de Roscoff, Place Georges Teissier, CS 90074, Roscoff cedex, France
| | - Maxine Thorel
- University of Caen-Basse Normandie et Centre National de la Recherche Scientifique, Institut d'Ecologie et d'Environnement, FRE 3484 Biologie des Mollusques Marins et des Ecosystèmes associés, Caen, France
| | - Daphné Grulois
- 1] University Pierre and Marie Curie (Paris 06), UMR 7144 Adaptation and Diversity in Marine Environments, Marine Phototrophic Procaryotes (MaPP) Team, Station Biologique de Roscoff, Place Georges Teissier, CS 90074, Roscoff cedex, France [2] Centre National de la Recherche Scientifique, UMR 7144 Adaptation and Diversity in Marine Environments, Oceanic Plankton Group, Station Biologique de Roscoff, Place Georges Teissier, CS 90074, Roscoff cedex, France
| | - Laurence Garczarek
- 1] University Pierre and Marie Curie (Paris 06), UMR 7144 Adaptation and Diversity in Marine Environments, Marine Phototrophic Procaryotes (MaPP) Team, Station Biologique de Roscoff, Place Georges Teissier, CS 90074, Roscoff cedex, France [2] Centre National de la Recherche Scientifique, UMR 7144 Adaptation and Diversity in Marine Environments, Oceanic Plankton Group, Station Biologique de Roscoff, Place Georges Teissier, CS 90074, Roscoff cedex, France
| | - Christophe Six
- 1] University Pierre and Marie Curie (Paris 06), UMR 7144 Adaptation and Diversity in Marine Environments, Marine Phototrophic Procaryotes (MaPP) Team, Station Biologique de Roscoff, Place Georges Teissier, CS 90074, Roscoff cedex, France [2] Centre National de la Recherche Scientifique, UMR 7144 Adaptation and Diversity in Marine Environments, Oceanic Plankton Group, Station Biologique de Roscoff, Place Georges Teissier, CS 90074, Roscoff cedex, France
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Humily F, Partensky F, Six C, Farrant GK, Ratin M, Marie D, Garczarek L. A gene island with two possible configurations is involved in chromatic acclimation in marine Synechococcus. PLoS One 2013; 8:e84459. [PMID: 24391958 PMCID: PMC3877281 DOI: 10.1371/journal.pone.0084459] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [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: 09/04/2013] [Accepted: 11/21/2013] [Indexed: 12/31/2022] Open
Abstract
Synechococcus, the second most abundant oxygenic phototroph in the marine environment, harbors the largest pigment diversity known within a single genus of cyanobacteria, allowing it to exploit a wide range of light niches. Some strains are capable of Type IV chromatic acclimation (CA4), a process by which cells can match the phycobilin content of their phycobilisomes to the ambient light quality. Here, we performed extensive genomic comparisons to explore the diversity of this process within the marine Synechococcus radiation. A specific gene island was identified in all CA4-performing strains, containing two genes (fciA/b) coding for possible transcriptional regulators and one gene coding for a phycobilin lyase. However, two distinct configurations of this cluster were observed, depending on the lineage. CA4-A islands contain the mpeZ gene, encoding a recently characterized phycoerythrobilin lyase-isomerase, and a third, small, possible regulator called fciC. In CA4-B islands, the lyase gene encodes an uncharacterized relative of MpeZ, called MpeW. While mpeZ is expressed more in blue light than green light, this is the reverse for mpeW, although only small phenotypic differences were found among chromatic acclimaters possessing either CA4 island type. This study provides novel insights into understanding both diversity and evolution of the CA4 process.
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Affiliation(s)
- Florian Humily
- Université Pierre et Marie Curie (Paris VI), Station Biologique, Roscoff, France
- Centre National de la Recherche Scientifique (CNRS), UMR 7144, Oceanic Plankton group, Marine Phototrophic Prokaryotes team, Roscoff, France
| | - Frédéric Partensky
- Université Pierre et Marie Curie (Paris VI), Station Biologique, Roscoff, France
- Centre National de la Recherche Scientifique (CNRS), UMR 7144, Oceanic Plankton group, Marine Phototrophic Prokaryotes team, Roscoff, France
| | - Christophe Six
- Université Pierre et Marie Curie (Paris VI), Station Biologique, Roscoff, France
- Centre National de la Recherche Scientifique (CNRS), UMR 7144, Oceanic Plankton group, Marine Phototrophic Prokaryotes team, Roscoff, France
| | - Gregory K. Farrant
- Université Pierre et Marie Curie (Paris VI), Station Biologique, Roscoff, France
- Centre National de la Recherche Scientifique (CNRS), UMR 7144, Oceanic Plankton group, Marine Phototrophic Prokaryotes team, Roscoff, France
| | - Morgane Ratin
- Université Pierre et Marie Curie (Paris VI), Station Biologique, Roscoff, France
- Centre National de la Recherche Scientifique (CNRS), UMR 7144, Oceanic Plankton group, Marine Phototrophic Prokaryotes team, Roscoff, France
| | - Dominique Marie
- Université Pierre et Marie Curie (Paris VI), Station Biologique, Roscoff, France
- Centre National de la Recherche Scientifique (CNRS), UMR 7144, Oceanic Plankton group, Marine Phototrophic Prokaryotes team, Roscoff, France
| | - Laurence Garczarek
- Université Pierre et Marie Curie (Paris VI), Station Biologique, Roscoff, France
- Centre National de la Recherche Scientifique (CNRS), UMR 7144, Oceanic Plankton group, Marine Phototrophic Prokaryotes team, Roscoff, France
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Marchand E, Prat C, Jeannin C, Lafont E, Bergmann T, Flusin O, Rizzi J, Roux N, Busso V, Deniau J, Noel H, Vaillant V, Leparc-Goffart I, Six C, Paty MC. Autochthonous case of dengue in France, October 2013. ACTA ACUST UNITED AC 2013; 18:20661. [PMID: 24342514 DOI: 10.2807/1560-7917.es2013.18.50.20661] [Citation(s) in RCA: 126] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
In October 2013, autochthonous dengue fever was diagnosed in a laboratory technician in Bouches-du-Rhone, southern France, a department colonised by Aedes albopictus since 2010. After ruling out occupational contamination, we identified the likely chain of local vector-borne transmission from which the autochthonous case arose. Though limited, this second occurrence of autochthonous dengue transmission in France highlights that efforts should be continued to rapidly detect dengue virus introduction and prevent its further dissemination in France.
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Affiliation(s)
- E Marchand
- Regional office of the French Institute for Public Health Surveillance (Cire Sud), Marseille, France
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Noisette F, Duong G, Six C, Davoult D, Martin S. Effects of elevated pCO2 on the metabolism of a temperate rhodolith Lithothamnion corallioides grown under different temperatures. J Phycol 2013; 49:746-757. [PMID: 27007207 DOI: 10.1111/jpy.12085] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2012] [Accepted: 05/08/2013] [Indexed: 06/05/2023]
Abstract
Coralline algae are considered among the most sensitive species to near future ocean acidification. We tested the effects of elevated pCO2 on the metabolism of the free-living coralline alga Lithothamnion corallioides ("maerl") and the interactions with changes in temperature. Specimens were collected in North Brittany (France) and grown for 3 months at pCO2 of 380 (ambient pCO2 ), 550, 750, and 1000 μatm (elevated pCO2 ) and at successive temperatures of 10°C (ambient temperature in winter), 16°C (ambient temperature in summer), and 19°C (ambient temperature in summer +3°C). At each temperature, gross primary production, respiration (oxygen flux), and calcification (alkalinity flux) rates were assessed in the light and dark. Pigments were determined by HPLC. Chl a, carotene, and zeaxanthin were the three major pigments found in L. corallioides thalli. Elevated pCO2 did not affect pigment content while temperature slightly decreased zeaxanthin and carotene content at 10°C. Gross production was not affected by temperature but was significantly affected by pCO2 with an increase between 380 and 550 μatm. Light, dark, and diel (24 h) calcification rates strongly decreased with increasing pCO2 regardless of the temperature. Although elevated pCO2 only slightly affected gross production in L. corallioides, diel net calcification was reduced by up to 80% under the 1,000 μatm treatment. Our findings suggested that near future levels of CO2 will have profound consequences for carbon and carbonate budgets in rhodolith beds and for the sustainability of these habitats.
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Affiliation(s)
- Fanny Noisette
- UPMC Univ. Paris 6, CNRS, UMR 7144, Station Biologique de Roscoff, Place Georges Teissier, Roscoff Cedex, 29688, France
| | - Gwendoline Duong
- UPMC Univ. Paris 6, CNRS, UMR 7144, Station Biologique de Roscoff, Place Georges Teissier, Roscoff Cedex, 29688, France
| | - Christophe Six
- UPMC Univ. Paris 6, CNRS, UMR 7144, Station Biologique de Roscoff, Place Georges Teissier, Roscoff Cedex, 29688, France
| | - Dominique Davoult
- UPMC Univ. Paris 6, CNRS, UMR 7144, Station Biologique de Roscoff, Place Georges Teissier, Roscoff Cedex, 29688, France
| | - Sophie Martin
- UPMC Univ. Paris 6, CNRS, UMR 7144, Station Biologique de Roscoff, Place Georges Teissier, Roscoff Cedex, 29688, France
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Bretaudeau A, Coste F, Humily F, Garczarek L, Le Corguillé G, Six C, Ratin M, Collin O, Schluchter WM, Partensky F. CyanoLyase: a database of phycobilin lyase sequences, motifs and functions. Nucleic Acids Res 2012; 41:D396-401. [PMID: 23175607 PMCID: PMC3531064 DOI: 10.1093/nar/gks1091] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
CyanoLyase (http://cyanolyase.genouest.org/) is a manually curated sequence and motif database of phycobilin lyases and related proteins. These enzymes catalyze the covalent ligation of chromophores (phycobilins) to specific binding sites of phycobiliproteins (PBPs). The latter constitute the building bricks of phycobilisomes, the major light-harvesting systems of cyanobacteria and red algae. Phycobilin lyases sequences are poorly annotated in public databases. Sequences included in CyanoLyase were retrieved from all available genomes of these organisms and a few others by similarity searches using biochemically characterized enzyme sequences and then classified into 3 clans and 32 families. Amino acid motifs were computed for each family using Protomata learner. CyanoLyase also includes BLAST and a novel pattern matching tool (Protomatch) that allow users to rapidly retrieve and annotate lyases from any new genome. In addition, it provides phylogenetic analyses of all phycobilin lyases families, describes their function, their presence/absence in all genomes of the database (phyletic profiles) and predicts the chromophorylation of PBPs in each strain. The site also includes a thorough bibliography about phycobilin lyases and genomes included in the database. This resource should be useful to scientists and companies interested in natural or artificial PBPs, which have a number of biotechnological applications, notably as fluorescent markers.
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Aboukais S, Orenes C, Six C, Malfait P. Vaccination du personnel au sein des établissements hébergeant des personnes âgées, région Provence-Alpes-Côte d’Azur, France. Rev Epidemiol Sante Publique 2012. [DOI: 10.1016/j.respe.2012.06.265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Mella-Flores D, Six C, Ratin M, Partensky F, Boutte C, Le Corguillé G, Marie D, Blot N, Gourvil P, Kolowrat C, Garczarek L. Prochlorococcus and Synechococcus have Evolved Different Adaptive Mechanisms to Cope with Light and UV Stress. Front Microbiol 2012; 3:285. [PMID: 23024637 PMCID: PMC3441193 DOI: 10.3389/fmicb.2012.00285] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2012] [Accepted: 07/19/2012] [Indexed: 11/13/2022] Open
Abstract
Prochlorococcus and Synechococcus, which numerically dominate vast oceanic areas, are the two most abundant oxygenic phototrophs on Earth. Although they require solar energy for photosynthesis, excess light and associated high UV radiations can induce high levels of oxidative stress that may have deleterious effects on their growth and productivity. Here, we compared the photophysiologies of the model strains Prochlorococcus marinus PCC 9511 and Synechococcus sp. WH7803 grown under a bell-shaped light/dark cycle of high visible light supplemented or not with UV. Prochlorococcus exhibited a higher sensitivity to photoinactivation than Synechococcus under both conditions, as shown by a larger drop of photosystem II (PSII) quantum yield at noon and different diel patterns of the D1 protein pool. In the presence of UV, the PSII repair rate was significantly depressed at noon in Prochlorococcus compared to Synechococcus. Additionally, Prochlorococcus was more sensitive than Synechococcus to oxidative stress, as shown by the different degrees of PSII photoinactivation after addition of hydrogen peroxide. A transcriptional analysis also revealed dramatic discrepancies between the two organisms in the diel expression patterns of several genes involved notably in the biosynthesis and/or repair of photosystems, light-harvesting complexes, CO(2) fixation as well as protection mechanisms against light, UV, and oxidative stress, which likely translate profound differences in their light-controlled regulation. Altogether our results suggest that while Synechococcus has developed efficient ways to cope with light and UV stress, Prochlorococcus cells seemingly survive stressful hours of the day by launching a minimal set of protection mechanisms and by temporarily bringing down several key metabolic processes. This study provides unprecedented insights into understanding the distinct depth distributions and dynamics of these two picocyanobacteria in the field.
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Affiliation(s)
- Daniella Mella-Flores
- Station Biologique, UPMC-Université Paris VIRoscoff, France
- Groupe Plancton Océanique, CNRS, UMR 7144Roscoff, France
- Departamento de Ecología, Facultad de Ciencias Biologicas, Pontificia Universidad Catolica de ChileSantiago, Chile
| | - Christophe Six
- Station Biologique, UPMC-Université Paris VIRoscoff, France
- Groupe Plancton Océanique, CNRS, UMR 7144Roscoff, France
| | - Morgane Ratin
- Station Biologique, UPMC-Université Paris VIRoscoff, France
- Groupe Plancton Océanique, CNRS, UMR 7144Roscoff, France
| | - Frédéric Partensky
- Station Biologique, UPMC-Université Paris VIRoscoff, France
- Groupe Plancton Océanique, CNRS, UMR 7144Roscoff, France
| | - Christophe Boutte
- Station Biologique, UPMC-Université Paris VIRoscoff, France
- Groupe Plancton Océanique, CNRS, UMR 7144Roscoff, France
| | - Gildas Le Corguillé
- Station Biologique, UPMC-Université Paris VIRoscoff, France
- CNRS, FR 2424, Service Informatique et GénomiqueRoscoff, France
| | - Dominique Marie
- Station Biologique, UPMC-Université Paris VIRoscoff, France
- Groupe Plancton Océanique, CNRS, UMR 7144Roscoff, France
| | - Nicolas Blot
- Station Biologique, UPMC-Université Paris VIRoscoff, France
- Groupe Plancton Océanique, CNRS, UMR 7144Roscoff, France
- Laboratoire Microorganismes: Génome et Environnement, Clermont Université, Université Blaise PascalClermont-Ferrand, France
- Laboratoire Microorganismes: Génome et Environnement, CNRS, UMR 6023Aubière, France
| | - Priscillia Gourvil
- Station Biologique, UPMC-Université Paris VIRoscoff, France
- Groupe Plancton Océanique, CNRS, UMR 7144Roscoff, France
| | - Christian Kolowrat
- Station Biologique, UPMC-Université Paris VIRoscoff, France
- Groupe Plancton Océanique, CNRS, UMR 7144Roscoff, France
- Center for Doctoral Studies, University of ViennaVienna, Austria
| | - Laurence Garczarek
- Station Biologique, UPMC-Université Paris VIRoscoff, France
- Groupe Plancton Océanique, CNRS, UMR 7144Roscoff, France
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Blot N, Mella-Flores D, Six C, Le Corguillé G, Boutte C, Peyrat A, Monnier A, Ratin M, Gourvil P, Campbell DA, Garczarek L. Light history influences the response of the marine cyanobacterium Synechococcus sp. WH7803 to oxidative stress. Plant Physiol 2011; 156:1934-54. [PMID: 21670225 PMCID: PMC3149967 DOI: 10.1104/pp.111.174714] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2011] [Accepted: 06/09/2011] [Indexed: 05/23/2023]
Abstract
Marine Synechococcus undergo a wide range of environmental stressors, especially high and variable irradiance, which may induce oxidative stress through the generation of reactive oxygen species (ROS). While light and ROS could act synergistically on the impairment of photosynthesis, inducing photodamage and inhibiting photosystem II repair, acclimation to high irradiance is also thought to confer resistance to other stressors. To identify the respective roles of light and ROS in the photoinhibition process and detect a possible light-driven tolerance to oxidative stress, we compared the photophysiological and transcriptomic responses of Synechococcus sp. WH7803 acclimated to low light (LL) or high light (HL) to oxidative stress, induced by hydrogen peroxide (H₂O₂) or methylviologen. While photosynthetic activity was much more affected in HL than in LL cells, only HL cells were able to recover growth and photosynthesis after the addition of 25 μM H₂O₂. Depending upon light conditions and H₂O₂ concentration, the latter oxidizing agent induced photosystem II inactivation through both direct damage to the reaction centers and inhibition of its repair cycle. Although the global transcriptome response appeared similar in LL and HL cells, some processes were specifically induced in HL cells that seemingly helped them withstand oxidative stress, including enhancement of photoprotection and ROS detoxification, repair of ROS-driven damage, and regulation of redox state. Detection of putative LexA binding sites allowed the identification of the putative LexA regulon, which was down-regulated in HL compared with LL cells but up-regulated by oxidative stress under both growth irradiances.
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Vandenbos F, Gal J, Dandine M, Six C, Veyres P, Chappuis V, Diez M, Mazzoni L, Daideri G, Bodokh I, Carassou-Maillan A, Chamorey E. [Assessing the wearing of jewellery by French healthcare professionals]. Med Mal Infect 2011; 41:192-6. [PMID: 21251781 DOI: 10.1016/j.medmal.2010.12.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2010] [Revised: 05/27/2010] [Accepted: 12/14/2010] [Indexed: 11/25/2022]
Abstract
OBJECTIVE A prospective observation study was undertaken in seven medical centers, in the French region Alpes-Maritime, to assess nail hygiene of healthcare professionals and how often they wear hand jewellery. METHOD Seven hundred and six healthcare workers in seven medical centers were interviewed from March to April 2008. RESULTS Among the 706 professionals, 306 (43%) were wearing one or several pieces of jewellery. The nails of 81 (11.5%) were non-standard according to guidelines. Three hundred and forty-four health care professionals (49%) were wearing one or several pieces of jewellery and/or presented with non-standard nails. In univariate analysis, the wearing of jewellery was linked to the medical centre (P<0.001), to the professional category (p<0.001), to the number of times people washed their hands or used hand gel per day (ABHR) by categories (<10 times per day or ≥10 times per day) (P<0.017). In the multivariate analysis, the risk factors linked to the wearing of jewellery were the medical centers, the professional category, and the age. CONCLUSION There are still too many healthcare professionals who do not comply to French recommendations on hand hygiene concerning the wearing of jewellery and nail hygiene standards.
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Affiliation(s)
- F Vandenbos
- Centre de réhabilitation cardiorespiratoire, centre de soins de suite et de rééducation La Maison du Mineur, 577 avenue Henri-Giraud, Vence, France.
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Six C, Blanes de Canecaude J, Duponchel JL, Lafont E, Decoppet A, Travanut M, Pingeon JM, Coulon L, Peloux-Petiot F, Grenier-Tisserant P, Delarozière JC, Charlet F, Malfait P. Spotlight on measles 2010: Measles outbreak in the Provence-Alpes-Côte d’Azur region, France, January to November 2010 - substantial underreporting of cases. Euro Surveill 2010. [DOI: 10.2807/ese.15.50.19754-en] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Binary file ES_Abstracts_Final_ECDC.txt matches
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Affiliation(s)
- C Six
- Regional Office of the French Institute for Public Health Surveillance (Cire Sud), Marseilles, France
| | - J Blanes de Canecaude
- Regional Health Agency (Agence régionale de santé, ARS) of Provence-Alpes-Côte d’Azur, Marseille, Avignon, Digne-les-Bains, Gap, Nice, Toulon, France
| | - J L Duponchel
- Regional Health Agency (Agence régionale de santé, ARS) of Provence-Alpes-Côte d’Azur, Marseille, Avignon, Digne-les-Bains, Gap, Nice, Toulon, France
| | - E Lafont
- Regional Health Agency (Agence régionale de santé, ARS) of Provence-Alpes-Côte d’Azur, Marseille, Avignon, Digne-les-Bains, Gap, Nice, Toulon, France
| | - A Decoppet
- Regional Health Agency (Agence régionale de santé, ARS) of Provence-Alpes-Côte d’Azur, Marseille, Avignon, Digne-les-Bains, Gap, Nice, Toulon, France
| | - M Travanut
- Regional Health Agency (Agence régionale de santé, ARS) of Provence-Alpes-Côte d’Azur, Marseille, Avignon, Digne-les-Bains, Gap, Nice, Toulon, France
| | - J M Pingeon
- Regional Health Agency (Agence régionale de santé, ARS) of Provence-Alpes-Côte d’Azur, Marseille, Avignon, Digne-les-Bains, Gap, Nice, Toulon, France
| | - L Coulon
- Regional Health Agency (Agence régionale de santé, ARS) of Provence-Alpes-Côte d’Azur, Marseille, Avignon, Digne-les-Bains, Gap, Nice, Toulon, France
| | - F Peloux-Petiot
- Regional Health Agency (Agence régionale de santé, ARS) of Provence-Alpes-Côte d’Azur, Marseille, Avignon, Digne-les-Bains, Gap, Nice, Toulon, France
| | - P Grenier-Tisserant
- Regional Health Agency (Agence régionale de santé, ARS) of Provence-Alpes-Côte d’Azur, Marseille, Avignon, Digne-les-Bains, Gap, Nice, Toulon, France
| | - J C Delarozière
- Interregional infection control coordinating centre (CClin), Marseilles, France
| | - F Charlet
- Regional Health Agency (Agence régionale de santé, ARS) of Provence-Alpes-Côte d’Azur, Marseille, Avignon, Digne-les-Bains, Gap, Nice, Toulon, France
| | - P Malfait
- Regional Office of the French Institute for Public Health Surveillance (Cire Sud), Marseilles, France
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Six C, Blanes de Canecaude J, Duponchel J, Lafont E, Decoppet A, Travanut M, Pingeon J, Coulon L, Peloux-Petiot F, Grenier-Tisserant P, Delaroziere J, Charlet F, Malfait P. Spotlight on measles 2010: Measles outbreak in the Provence-Alpes-Côte d’Azur region, France, January to November 2010 - substantial underreporting of cases: measles outbreak in the Provence-Alpes-Cote d Azur region, France, January to November 2010 - substantial underreporting of cases. Euro Surveill 2010; 15:19754. [PMID: 21172174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023] Open
Affiliation(s)
- C Six
- Regional Office of the French Institute for Public Health Surveillance (Cire Sud), Marseilles, France.
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Six C, Regi JC, Deniau J, Garnier JP. Impact de la semaine européenne de vaccination sur l’activité vaccinale en région Paca, de 2007 à 2008. Rev Epidemiol Sante Publique 2010. [DOI: 10.1016/j.respe.2010.06.162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
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Key T, McCarthy A, Campbell DA, Six C, Roy S, Finkel ZV. Cell size trade-offs govern light exploitation strategies in marine phytoplankton. Environ Microbiol 2010; 12:95-104. [DOI: 10.1111/j.1462-2920.2009.02046.x] [Citation(s) in RCA: 146] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Six C, Sherrard R, Lionard M, Roy S, Campbell DA. Photosystem II and pigment dynamics among ecotypes of the green alga Ostreococcus. Plant Physiol 2009; 151:379-90. [PMID: 19587099 PMCID: PMC2735990 DOI: 10.1104/pp.109.140566] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2009] [Accepted: 07/05/2009] [Indexed: 05/18/2023]
Abstract
We investigated the photophysiological responses of three ecotypes of the picophytoplankter Ostreococcus and a larger prasinophyte Pyramimonas obovata to a sudden increase in light irradiance. The deepwater Ostreococcus sp. RCC809 showed very high susceptibility to primary photoinactivation, likely a consequence of high oxidative stress, which may relate to the recently noted plastid terminal oxidase activity in this strain. The three Ostreococcus ecotypes were all capable of deploying modulation of the photosystem II repair cycle in order to cope with the light increase, but the effective clearance of photoinactivated D1 protein appeared to be slower in the deepwater Ostreococcus sp. RCC809, suggesting that this step is rate limiting in the photosystem II repair cycle in this strain. Moreover, the deepwater Ostreococcus accumulated lutein and showed substantial use of the xanthophyll cycle under light stress, demonstrating its high sensitivity to light fluctuations. The sustained component of the nonphotochemical quenching of fluorescence correlated well with the xanthophyll deepoxidation activity. Comparisons with the larger prasinophyte P. obovata suggest that the photophysiology of Ostreococcus ecotypes requires high photosystem II repair rates to counter a high susceptibility to photoinactivation, consistent with low pigment package effects in their minute-sized cells.
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Affiliation(s)
- Christophe Six
- Biology Department, Mount Allison University, Sackville, New Brunswick, Canada E4L 1G7.
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Boulay C, Abasova L, Six C, Vass I, Kirilovsky D. Occurrence and function of the orange carotenoid protein in photoprotective mechanisms in various cyanobacteria. Biochimica et Biophysica Acta (BBA) - Bioenergetics 2008; 1777:1344-54. [DOI: 10.1016/j.bbabio.2008.07.002] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2008] [Revised: 07/11/2008] [Accepted: 07/16/2008] [Indexed: 10/21/2022]
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Humbert C, Busson B, Six C, Gayral A, Gruselle M, Villain F, Tadjeddine A. Sum-frequency generation as a vibrational and electronic probe of the electrochemical interface and thin films. J Electroanal Chem (Lausanne) 2008. [DOI: 10.1016/j.jelechem.2008.02.008] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Franke F, Six C, Coulon L, Duponchel JL, Lepoutre A, Bidet P. Épidémie de scarlatine et d’angine streptococcique, Hautes-Alpes et Bouches-du-Rhône, 2007. Rev Epidemiol Sante Publique 2008. [DOI: 10.1016/j.respe.2008.06.169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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Berbis J, Six C, Delarozière JC, Charlet F, Masini B, Armengaud A, Vaux S, Malfait P. Dispositif de surveillance des cas groupés d’infections respiratoires aiguës basses dans les collectivités de personnes âgées de la région Provence-Alpes-Côte d’Azur. Rev Epidemiol Sante Publique 2008. [DOI: 10.1016/j.respe.2008.06.241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
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Franke F, Six C, Coulon L, Duponchel J, Lepoutre A, Bidet P. O-01 Épidémie de scarlatine et d’angine streptococcique, Hautes-Alpes et Bouches-du-Rhône, 2007. Med Mal Infect 2008. [DOI: 10.1016/s0399-077x(08)73198-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Berbis J, Six C, Delarozière J, Charlet F, Masini B, Vaux S, Malfait P. A-01 Dispositif de surveillance des cas groupés d’infections respiratoires aiguës basses dans les collectivités de personnes âgées de la région Provence-Alpes-Côte d’Azur. Med Mal Infect 2008. [DOI: 10.1016/s0399-077x(08)73061-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Garczarek L, Dufresne A, Blot N, Cockshutt AM, Peyrat A, Campbell DA, Joubin L, Six C. Function and evolution of the psbA gene family in marine Synechococcus: Synechococcus sp. WH7803 as a case study. ISME J 2008; 2:937-53. [PMID: 18509382 DOI: 10.1038/ismej.2008.46] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
In cyanobacteria, the D1 protein of photosystem II (PSII) is encoded by the psbA multigene family. In most freshwater strains, a D1:1 isoform of this protein is exchanged for a D1:2 isoform in response to various stresses, thereby altering PSII photochemistry. To investigate PSII responses to stress in marine Synechococcus, we acclimated cultures of the WH7803 strain to different growth irradiances and then exposed them to high light (HL) or ultraviolet (UV) radiation. Measurement of PSII quantum yield and quantitation of the D1 protein pool showed that HL-acclimated cells were more resistant to UV light than were low light- (LL) or medium light- (ML) acclimated cells. Both UV and HL induced the expression of psbA genes encoding D1:2 and the repression of the psbA gene encoding D1:1. Although three psbA genes encode identical D1:2 isoforms in Synechococcus sp. WH7803, only one was strongly stress responsive in our treatment conditions. Examination of 11 marine Synechococcus genomic sequences identified up to six psbA copies per genome, with always a single gene encoding D1:1. In phylogenetic analyses, marine Synechococcus genes encoding D1:1 clustered together, while the genes encoding D1:2 grouped by genome into subclusters. Moreover, examination of the genomic environment of psbA genes suggests that the D1:2 genes are hotspots for DNA recombination. Collectively, our observations suggest that while all psbA genes follow a concerted evolution within each genome, D1:2 coding genes are subject to intragenome homogenization most probably mediated by gene conversion.
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Affiliation(s)
- Laurence Garczarek
- Station Biologique, UMR 7144 CNRS et Université Pierre et Marie Curie, Roscoff cedex, France.
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Six C, Thomas JC, Garczarek L, Ostrowski M, Dufresne A, Blot N, Scanlan DJ, Partensky F. Diversity and evolution of phycobilisomes in marine Synechococcus spp.: a comparative genomics study. Genome Biol 2008; 8:R259. [PMID: 18062815 PMCID: PMC2246261 DOI: 10.1186/gb-2007-8-12-r259] [Citation(s) in RCA: 164] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2007] [Revised: 10/22/2007] [Accepted: 12/05/2007] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Marine Synechococcus owe their specific vivid color (ranging from blue-green to orange) to their large extrinsic antenna complexes called phycobilisomes, comprising a central allophycocyanin core and rods of variable phycobiliprotein composition. Three major pigment types can be defined depending on the major phycobiliprotein found in the rods (phycocyanin, phycoerythrin I or phycoerythrin II). Among strains containing both phycoerythrins I and II, four subtypes can be distinguished based on the ratio of the two chromophores bound to these phycobiliproteins. Genomes of eleven marine Synechococcus strains recently became available with one to four strains per pigment type or subtype, allowing an unprecedented comparative genomics study of genes involved in phycobilisome metabolism. RESULTS By carefully comparing the Synechococcus genomes, we have retrieved candidate genes potentially required for the synthesis of phycobiliproteins in each pigment type. This includes linker polypeptides, phycobilin lyases and a number of novel genes of uncharacterized function. Interestingly, strains belonging to a given pigment type have similar phycobilisome gene complements and organization, independent of the core genome phylogeny (as assessed using concatenated ribosomal proteins). While phylogenetic trees based on concatenated allophycocyanin protein sequences are congruent with the latter, those based on phycocyanin and phycoerythrin notably differ and match the Synechococcus pigment types. CONCLUSION We conclude that the phycobilisome core has likely evolved together with the core genome, while rods must have evolved independently, possibly by lateral transfer of phycobilisome rod genes or gene clusters between Synechococcus strains, either via viruses or by natural transformation, allowing rapid adaptation to a variety of light niches.
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Affiliation(s)
- Christophe Six
- UMR 7144 Université Paris VI and CNRS, Station Biologique, Groupe Plancton Océanique, F-29682 Roscoff cedex, France.
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Abstract
Prochlorococcus and Synechococcus picocyanobacteria are dominant contributors to marine primary production over large areas of the ocean. Phytoplankton cells are entrained in the water column and are thus often exposed to rapid changes in irradiance within the upper mixed layer of the ocean. An upward fluctuation in irradiance can result in photosystem II photoinactivation exceeding counteracting repair rates through protein turnover, thereby leading to net photoinhibition of primary productivity, and potentially cell death. Here we show that the effective cross-section for photosystem II photoinactivation is conserved across the picocyanobacteria, but that their photosystem II repair capacity and protein-specific photosystem II light capture are negatively correlated and vary widely across the strains. The differences in repair rate correspond to the light and nutrient conditions that characterize the site of origin of the Prochlorococcus and Synechococcus isolates, and determine the upward fluctuation in irradiance they can tolerate, indicating that photoinhibition due to transient high-light exposure influences their distribution in the ocean.
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Affiliation(s)
- Christophe Six
- Mount Allison University, Sackville, New Brunswick, Canada
| | - Zoe V. Finkel
- Mount Allison University, Sackville, New Brunswick, Canada
| | | | - Douglas A. Campbell
- Mount Allison University, Sackville, New Brunswick, Canada
- * To whom correspondence should be addressed. E-mail:
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Six C, Joubin L, Partensky F, Holtzendorff J, Garczarek L. UV-induced phycobilisome dismantling in the marine picocyanobacterium Synechococcus sp. WH8102. Photosynth Res 2007; 92:75-86. [PMID: 17505911 DOI: 10.1007/s11120-007-9170-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2006] [Accepted: 04/07/2007] [Indexed: 05/15/2023]
Abstract
The marine picocyanobacterium Synechococcus sp. WH8102 was submitted to ultraviolet (UV-A and B) radiations and the effects of this stress on reaction center II and phycobilisome integrity were studied using a combination of biochemical, biophysical and molecular biology techniques. Under the UV conditions that were applied (4.3 W m(-2) UV-A and 0.86 W m(-2) UV-B), no significant cell mortality and little chlorophyll degradation occurred during the 5 h time course experiment. However, pulse amplitude modulated (PAM) fluorimetry analyses revealed a rapid photoinactivation of reaction centers II. Indeed, a dramatic decrease of the D1 protein amount was observed, despite a large and rapid increase in the expression level of the psbA gene pool. Our results suggest that D1 protein degradation was accompanied (or followed) by the disruption of the N-terminal domain of the anchor linker polypeptide LCM, which in turn led to the disconnection of the phycobilisome complex from the thylakoid membrane. Furthermore, time course analyses of in vivo fluorescence emission spectra suggested a partial dismantling of phycobilisome rods. This was confirmed by characterization of isolated antenna complexes by SDS-PAGE and immunoblotting analyses which allowed us to locate the disruption site of the rods near the phycoerythrin I-phycoerythrin II junction. In addition, genes encoding phycobilisome components, including alpha-subunits of all phycobiliproteins and phycoerythrin linker polypeptides were all down regulated in response to UV stress. Phycobilisome alteration could be the consequence of direct UV-induced photodamages and/or the result of a protease-mediated process.
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Affiliation(s)
- Christophe Six
- Station Biologique, UMR 7144 CNRS et Université Pierre et Marie Curie, B.P. 74, 29682, Roscoff cedex, France
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Abstract
Chromatic adaptation (CA) in cyanobacteria has provided a model system for the study of the environmental control of photophysiology for several decades. All forms of CA that have been examined so far (types II and III) involve changes in the relative contents of phycoerythrin (PE) and/or phycocyanin when cells are shifted from red to green light and vice versa. However, the chromophore compositions of these polypeptides are not altered. Some marine Synechococcus species strains, which possess two PE forms (PEI and PEII), carry out another type of CA (type IV), occurring during shifts from blue to green or white light. Two chromatically adapting strains of marine Synechococcus recently isolated from the Gulf of Mexico were utilized to elucidate the mechanism of type IV CA. During this process, no change in the relative contents of PEI and PEII was observed. Instead, the ratio of the two chromophores bound to PEII, phycourobilin and phycoerythrobilin, is high under blue light and low under white light. Mass spectroscopy analyses of isolated PEII alpha- and beta-subunits show that there is a single PEII protein type under all light climates. The CA process seems to specifically affect the chromophorylation of the PEII (and possibly PEI) alpha chain. We propose a likely process for type IV CA, which involves the enzymatic activity of one or several phycobilin lyases and/or lyase-isomerases differentially controlled by the ambient light quality. Phylogenetic analyses based on the 16S rRNA gene confirm that type IV CA is not limited to a single clade of marine Synechococcus.
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Affiliation(s)
- Craig Everroad
- Center for Ecology and Evolution, Department of Biology, University of Oregon, Eugene, Oregon 97403, USA
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Six C, Worden AZ, Rodríguez F, Moreau H, Partensky F. New Insights into the Nature and Phylogeny of Prasinophyte Antenna Proteins: Ostreococcus tauri, a Case Study. Mol Biol Evol 2005; 22:2217-30. [PMID: 16049197 DOI: 10.1093/molbev/msi220] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The basal position of the Mamiellales (Prasinophyceae) within the green lineage makes these unicellular organisms key to elucidating early stages in the evolution of chlorophyll a/b-binding light-harvesting complexes (LHCs). Here, we unveil the complete and unexpected diversity of Lhc proteins in Ostreococcus tauri, a member of the Mamiellales order, based on results from complete genome sequencing. Like Mantoniella squamata, O. tauri possesses a number of genes encoding an unusual prasinophyte-specific Lhc protein type herein designated "Lhcp". Biochemical characterization of the complexes revealed that these polypeptides, which bind chlorophylls a, b, and a chlorophyll c-like pigment (Mg-2,4-divinyl-phaeoporphyrin a5 monomethyl ester) as well as a number of unusual carotenoids, are likely predominant. They are retrieved to some extent in both reaction center I (RCI)- and RCII-enriched fractions, suggesting a possible association to both photosystems. However, in sharp contrast to previous reports on LHCs of M. squamata, O. tauri also possesses other LHC subpopulations, including LHCI proteins (encoded by five distinct Lhca genes) and the minor LHCII polypeptides, CP26 and CP29. Using an antibody against plant Lhca2, we unambiguously show that LHCI proteins are present not only in O. tauri, in which they are likely associated to RCI, but also in other Mamiellales, including M. squamata. With the exception of Lhcp genes, all the identified Lhc genes are present in single copy only. Overall, the discovery of LHCI proteins in these prasinophytes, combined with the lack of the major LHCII polypeptides found in higher plants or other green algae, supports the hypothesis that the latter proteins appeared subsequent to LHCI proteins. The major LHC of prasinophytes might have arisen prior to the LHCII of other chlorophyll a/b-containing organisms, possibly by divergence of a LHCI gene precursor. However, the discovery in O. tauri of CP26-like proteins, phylogenetically placed at the base of the major LHCII protein clades, yields new insight to the origin of these antenna proteins, which have evolved separately in higher plants and green algae. Its diverse but numerically limited suite of Lhc genes renders O. tauri an exceptional model system for future research on the evolution and function of LHC components.
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Humbert C, Busson B, Abid JP, Six C, Girault H, Tadjeddine A. Self-assembled organic monolayers on gold nanoparticles: A study by sum-frequency generation combined with UV–vis spectroscopy. Electrochim Acta 2005. [DOI: 10.1016/j.electacta.2004.10.084] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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