@article {ferrieux_comparative_2022, title = {Comparative Thermophysiology of Marine Synechococcus CRD1 Strains Isolated From Different Thermal Niches in Iron-Depleted Areas}, journal = {Frontiers in Microbiology}, volume = {13}, year = {2022}, abstract = {Marine Synechococcus cyanobacteria are ubiquitous in the ocean, a feature likely related to their extensive genetic diversity. Amongst the major lineages, clades I and IV preferentially thrive in temperate and cold, nutrient-rich waters, whilst clades II and III prefer warm, nitrogen or phosphorus-depleted waters. The existence of such cold (I/IV) and warm (II/III) thermotypes is corroborated by physiological characterization of representative strains. A fifth clade, CRD1, was recently shown to dominate the Synechococcus community in iron-depleted areas of the world ocean and to encompass three distinct ecologically significant taxonomic units (ESTUs CRD1A-C) occupying different thermal niches, suggesting that distinct thermotypes could also occur within this clade. Here, using comparative thermophysiology of strains representative of these three CRD1 ESTUs we show that the CRD1A strain MITS9220 is a warm thermotype, the CRD1B strain BIOS-U3-1 a cold temperate thermotype, and the CRD1C strain BIOS-E4-1 a warm temperate stenotherm. Curiously, the CRD1B thermotype lacks traits and/or genomic features typical of cold thermotypes. In contrast, we found specific physiological traits of the CRD1 strains compared to their clade I, II, III, and IV counterparts, including a lower growth rate and photosystem II maximal quantum yield at most temperatures and a higher turnover rate of the D1 protein. Together, our data suggests that the CRD1 clade prioritizes adaptation to low-iron conditions over temperature adaptation, even though the occurrence of several CRD1 thermotypes likely explains why the CRD1 clade as a whole occupies most iron-limited waters.}, keywords = {RCC2374, RCC2385, RCC2533, RCC2534, RCC2571, RCC515, rcc539, rcc791}, issn = {1664-302X}, doi = {10.3389/fmicb.2022.893413}, url = {https://www.frontiersin.org/article/10.3389/fmicb.2022.893413}, author = {Ferrieux, Mathilde and Dufour, Louison and Dor{\'e}, Hugo and Ratin, Morgane and Gu{\'e}neugu{\`e}s, Audrey and Chasselin, L{\'e}o and Marie, Dominique and Rigaut-jalabert, Fabienne and Le Gall, Florence and Sciandra, Th{\'e}o and Monier, Garance and Hoebeke, Mark and Corre, Erwan and Xia, Xiaomin and Liu, Hongbin and Scanlan, David J. and Partensky, Fr{\'e}d{\'e}ric and Garczarek, Laurence} } @article {grebert_diversity_2022, title = {Diversity and evolution of pigment types in marine \textit{Synechococcus cyanobacteria}, journal = {Genome Biology and Evolution}, year = {2022}, pages = {evac035}, abstract = {DNA integration and site-specific recombination, suggesting that their genomic variability relies D in part on a {\textquoteleft}tycheposon{\textquoteright}-like mechanism. Comparison of the phylogenies obtained for PBS and E core genes revealed that the evolutionary history of PBS rod genes differs from the core T genome and is characterized by the co-existence of different alleles and frequent allelic P exchange. We propose a scenario for the evolution of the different pigment types and highlight E the importance of incomplete lineage sorting in maintaining a wide diversity of pigment types in C different Synechococcus lineages despite multiple speciation events.}, keywords = {RCC307, to add}, issn = {1759-6653}, doi = {10.1093/gbe/evac035}, url = {https://academic.oup.com/gbe/advance-article/doi/10.1093/gbe/evac035/6547267}, author = {Gr{\'e}bert, Th{\'e}ophile and Garczarek, Laurence and Daubin, Vincent and Humily, Florian and Marie, Dominique and Ratin, Morgane and Devailly, Alban and Farrant, Gregory K. and Mary, Isabelle and Mella-Flores, Daniella and Tanguy, Gwenn and Labadie, Karine and Wincker, Patrick and Kehoe, David M. and Partensky, Fr{\'e}d{\'e}ric}, editor = {Angert, Esther} } @article {dore_global_2022, title = {Global Phylogeography of Marine Synechococcus in Coastal Areas Reveals Strong Community Shifts}, journal = {mSystems}, year = {2022}, note = {Publisher: American Society for Microbiology}, pages = {e00656{\textendash}22}, abstract = {Marine Synechococcus comprise a numerically and ecologically prominent phytoplankton group, playing a major role in both carbon cycling and trophic networks in all oceanic regions except in the polar oceans. Despite their high abundance in coastal areas, our knowledge of Synechococcus communities in these environments is based on only a few local studies. Here, we use the global metagenome data set of the Ocean Sampling Day (June 21st, 2014) to get a snapshot of the taxonomic composition of coastal Synechococcus communities worldwide, by recruitment on a reference database of 141 picocyanobacterial genomes, representative of the whole Prochlorococcus, Synechococcus, and Cyanobium diversity. This allowed us to unravel drastic community shifts over small to medium scale gradients of environmental factors, in particular along European coasts. The combined analysis of the phylogeography of natural populations and the thermophysiological characterization of eight strains, representative of the four major Synechococcus lineages (clades I to IV), also brought novel insights about the differential niche partitioning of clades I and IV, which most often co-dominate the Synechococcus community in cold and temperate coastal areas. Altogether, this study reveals several important characteristics and specificities of the coastal communities of Synechococcus worldwide. IMPORTANCE Synechococcus is the second most abundant phytoplanktonic organism on Earth, and its wide genetic diversity allowed it to colonize all the oceans except for polar waters, with different clades colonizing distinct oceanic niches. In recent years, the use of global metagenomics data sets has greatly improved our knowledge of {\textquotedblleft}who is where{\textquotedblright} by describing the distribution of Synechococcus clades or ecotypes in the open ocean. However, little is known about the global distribution of Synechococcus ecotypes in coastal areas, where Synechococcus is often the dominant phytoplanktonic organism. Here, we leverage the global Ocean Sampling Day metagenomics data set to describe Synechococcus community composition in coastal areas worldwide, revealing striking community shifts, in particular along the coasts of Europe. As temperature appears as an important driver of the community composition, we also characterize the thermal preferenda of 8 Synechococcus strains, bringing new insights into the adaptation to temperature of the dominant Synechococcus clades.}, keywords = {RCC1086, RCC1695, RCC2369, rcc2380, RCC2553, RCC2556, RCC2570, rcc791}, doi = {10.1128/msystems.00656-22}, url = {https://journals.asm.org/doi/full/10.1128/msystems.00656-22}, author = {Dor{\'e}, Hugo and Leconte, Jade and Guyet, Ulysse and Breton, Sol{\`e}ne and Farrant, Gregory K. and Demory, David and Ratin, Morgane and Hoebeke, Mark and Corre, Erwan and Pitt, Frances D. and Ostrowski, Martin and Scanlan, David J. and Partensky, Fr{\'e}d{\'e}ric and Six, Christophe and Garczarek, Laurence} } @article {haney_multiple_2022, title = {Multiple Photolyases Protect the Marine Cyanobacterium Synechococcus from Ultraviolet Radiation}, journal = {mBio}, volume = {13}, number = {4}, year = {2022}, month = {aug}, pages = {e01511{\textendash}22}, abstract = {

Marine cyanobacteria depend on light for photosynthesis, restricting their growth to the photic zone. The upper part of this layer is exposed to strong UV radiation (UVR), a DNA mutagen that can harm these microorganisms. To thrive in UVR-rich waters, marine cyanobacteria employ photoprotection strategies that are still not well defined. Among these are photolyases, light-activated enzymes that repair DNA dimers generated by UVR. Our analysis of genomes of 81 strains of Synechococcus, Cyanobium, and Prochlorococcus isolated from the world{\textquoteright}s oceans shows that they possess up to five genes encoding different members of the photolyase/cryptochrome family, including a photolyase with a novel domain arrangement encoded by either one or two separate genes. We disrupted the putative photolyase-encoding genes in Synechococcus sp. strain RS9916 and discovered that each gene contributes to the overall capacity of this organism to survive UVR. Additionally, each conferred increased survival after UVR exposure when transformed into Escherichia coli lacking its photolyase and SOS response. Our results provide the first evidence that this large set of photolyases endows Synechococcus with UVR resistance that is far superior to that of E. coli, but that, unlike for E. coli, these photolyases provide Synechococcus with the vast majority of its UVR tolerance.

}, keywords = {rcc555}, issn = {2150-7511}, doi = {10.1128/mbio.01511-22}, url = {https://journals.asm.org/doi/10.1128/mbio.01511-22}, author = {Haney, Allissa M. and Sanfilippo, Joseph E. and Garczarek, Laurence and Partensky, Fr{\'e}d{\'e}ric and Kehoe, David M.}, editor = {Ruby, Edward} } @article {carrigee_phycoerythrobilin_2022, title = {The phycoerythrobilin isomerization activity of MpeV in Synechococcus sp. WH8020 is prevented by the presence of a histidine at position 141 within its phycoerythrin-I β-subunit substrate}, journal = {Frontiers in Microbiology}, volume = {13}, year = {2022}, pages = {1011189}, abstract = {Marine Synechococcus efficiently harvest available light for photosynthesis using complex antenna systems, called phycobilisomes, composed of an allophycocyanin core surrounded by rods, which in the open ocean are always constituted of phycocyanin and two phycoerythrin (PE) types: PEI and PEII. These cyanobacteria display a wide pigment diversity primarily resulting from differences in the ratio of the two chromophores bound to PEs, the green-light absorbing phycoerythrobilin and the blue-light absorbing phycourobilin. Prior to phycobiliprotein assembly, bilin lyases post-translationally catalyze the ligation of phycoerythrobilin to conserved cysteine residues on α- or β-subunits, whereas the closely related lyase-isomerases isomerize phycoerythrobilin to phycourobilin during the attachment reaction. MpeV was recently shown in Synechococcus sp. RS9916 to be a lyase-isomerase which doubly links phycourobilin to two cysteine residues (C50 and C61; hereafter C50, 61) on the β-subunit of both PEI and PEII. Here we show that Synechococcus sp. WH8020, which belongs to the same pigment type as RS9916, contains MpeV that demonstrates lyase-isomerase activity on the PEII β-subunit but only lyase activity on the PEI β-subunit. We also demonstrate that occurrence of a histidine at position 141 of the PEI β-subunit from WH8020, instead of a leucine in its counterpart from RS9916, prevents the isomerization activity by WH8020 MpeV, showing for the first time that both the substrate and the enzyme play a role in the isomerization reaction. We propose a structural-based mechanism for the role of H141 in blocking isomerization. More generally, the knowledge of the amino acid present at position 141 of the β-subunits may be used to predict which phycobilin is bound at C50, 61 of both PEI and PEII from marine Synechococcus strains.}, keywords = {RCC2437, RCC307, RCC751}, issn = {1664-302X}, doi = {10.3389/fmicb.2022.1011189}, url = {https://www.frontiersin.org/articles/10.3389/fmicb.2022.1011189/full}, author = {Carrigee, Lyndsay A. and Frick, Jacob P. and Liu, Xindi and Karty, Jonathan A. and Trinidad, Jonathan C. and Tom, Irin P. and Yang, Xiaojing and Dufour, Louison and Partensky, Fr{\'e}d{\'e}ric and Schluchter, Wendy M.} } @article {grebert_molecular_2021, title = {Molecular bases of an alternative dual-enzyme system for light color acclimation of marine \textit{Synechococcus cyanobacteria}, journal = {Proceedings of the National Academy of Sciences}, volume = {118}, number = {9}, year = {2021}, pages = {e2019715118}, abstract = {

Marine Synechococcus cyanobacteria owe their ubiquity in part to the wide pigment diversity of their light-harvesting complexes. In open ocean waters, cells predominantly possess sophisticated antennae with rods composed of phycocyanin and two types of phycoerythrins (PEI and PEII). Some strains are specialized for harvesting either green or blue light, while others can dynamically modify their light absorption spectrum to match the dominant ambient color. This process, called type IV chromatic acclimation (CA4), has been linked to the presence of a small genomic island occurring in two configurations (CA4-A and CA4-B). While the CA4-A process has been partially characterized, the CA4-B process has remained an enigma. Here we characterize the function of two members of the phycobilin lyase E/F clan, MpeW and MpeQ, in Synechococcus sp. strain A15-62 and demonstrate their critical role in CA4-B. While MpeW, encoded in the CA4-B island and up-regulated in green light, attaches the green light-absorbing chromophore phycoerythrobilin to cysteine-83 of the PEII α-subunit in green light, MpeQ binds phycoerythrobilin and isomerizes it into the blue light-absorbing phycourobilin at the same site in blue light, reversing the relationship of MpeZ and MpeY in the CA4-A strain RS9916. Our data thus reveal key molecular differences between the two types of chromatic acclimaters, both highly abundant but occupying distinct complementary ecological niches in the ocean. They also support an evolutionary scenario whereby CA4-B island acquisition allowed former blue light specialists to become chromatic acclimaters, while former green light specialists would have acquired this capacity by gaining a CA4-A island.

}, keywords = {RCC2374, to add}, issn = {0027-8424, 1091-6490}, doi = {10.1073/pnas.2019715118}, url = {http://www.pnas.org/lookup/doi/10.1073/pnas.2019715118}, author = {Gr{\'e}bert, Th{\'e}ophile and Nguyen, Adam A. and Pokhrel, Suman and Joseph, Kes Lynn and Ratin, Morgane and Dufour, Louison and Chen, Bo and Haney, Allissa M. and Karty, Jonathan A. and Trinidad, Jonathan C. and Garczarek, Laurence and Schluchter, Wendy M. and Kehoe, David M. and Partensky, Fr{\'e}d{\'e}ric} } @article {Dore2020, title = {Evolutionary mechanisms of long-term genome diversification associated with niche partitioning in marine picocyanobacteria}, journal = {Frontiers in Microbiology}, volume = {11}, number = {September}, year = {2020}, note = {tex.mendeley-tags: RCC1084,RCC1085,RCC1086,RCC1087,RCC156,RCC158,RCC162,RCC2033,RCC2035,RCC2319,RCC2366,RCC2368,RCC2369,RCC2374,RCC2376,RCC2378,RCC2379,RCC2380,RCC2381,RCC2382,RCC2383,RCC2385,RCC2433,RCC2436,RCC2438,RCC2527,RCC2528,RCC2533,RCC2534,RCC2535,RCC2553,RCC2554,RCC2555,RCC2556,RCC2571,RCC2673,RCC278,RCC296,RCC307,RCC328,RCC3377,RCC407,RCC515,RCC539,RCC555,RCC556,RCC752,RCC753,RCC791}, month = {sep}, pages = {1{\textendash}23}, keywords = {amino-acid substitutions, comparative genomics, evolution, genomic islands, marine cyanobacteria, niche adaptation, Prochlorococcus, rcc1084, RCC1085, RCC1086, RCC1087, RCC156, RCC158, rcc162, RCC2033, RCC2035, RCC2319, RCC2366, RCC2368, RCC2369, RCC2374, RCC2376, RCC2378, RCC2379, rcc2380, RCC2381, rcc2382, RCC2383, RCC2385, RCC2433, RCC2436, RCC2438, RCC2527, RCC2528, RCC2533, RCC2534, RCC2535, RCC2553, RCC2554, RCC2555, RCC2556, RCC2571, RCC2673, RCC278, rcc296, RCC307, RCC328, RCC3377, RCC407, RCC515, rcc539, rcc555, RCC556, rcc752, RCC753, rcc791, Synechococcus}, issn = {1664-302X}, doi = {10.3389/fmicb.2020.567431}, url = {https://www.frontiersin.org/article/10.3389/fmicb.2020.567431/full}, author = {Dor{\'e}, Hugo and Farrant, Gregory K. and Guyet, Ulysse and Haguait, Julie and Humily, Florian and Ratin, Morgane and Pitt, Frances D. and Ostrowski, Martin and Six, Christophe and Brillet-Gu{\'e}guen, Loraine and Hoebeke, Mark and Bisch, Antoine and Le Corguill{\'e}, Gildas and Corre, Erwan and Labadie, Karine and Aury, Jean-Marc and Wincker, Patrick and Choi, Dong Han and Noh, Jae Hoon and Eveillard, Damien and Scanlan, David J. and Partensky, Fr{\'e}d{\'e}ric and Garczarek, Laurence} } @article {Guyet2020, title = {Synergic effects of temperature and irradiance on the physiology of the marine synechococcus strain WH7803}, journal = {Frontiers in Microbiology}, volume = {11}, year = {2020}, note = {Publisher: Frontiers Media S.A. tex.mendeley-tags: RCC752}, month = {jul}, pages = {1707}, 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.}, keywords = {light stress, marine cyanobacteria, rcc752, Synechococcus, temperature stress, transcriptomics, UV radiations}, issn = {1664302X}, doi = {10.3389/fmicb.2020.01707}, url = {www.frontiersin.org}, author = {Guyet, Ulysse and Nguyen, Ngoc A. and Dor{\'e}, Hugo and Haguait, Julie and Pittera, Justine and Conan, Ma{\"e}l and Ratin, Morgane and Corre, Erwan and Le Corguill{\'e}, Gildas and Brillet-Gu{\'e}guen, Loraine and Hoebeke, Mark and Six, Christophe and Steglich, Claudia and Siegel, Anne and Eveillard, Damien and Partensky, Fr{\'e}d{\'e}ric and Garczarek, Laurence} } @article {Sanfilippo2019, title = {Interplay between differentially expressed enzymes contributes to light color acclimation in marine Synechococcus}, journal = {Proceedings of the National Academy of Sciences}, volume = {116}, number = {13}, year = {2019}, note = {tex.mendeley-tags: RCC1086,RCC2035,RCC2380,RCC2382,RCC2385,RCC2433,RCC2437,RCC2528,RCC2533,RCC2534,RCC2535,RCC2571,RCC2673,RCC28,RCC307,RCC328,RCC515,RCC555,RCC791}, month = {mar}, pages = {6457{\textendash}6462}, abstract = {Marine Synechococcus , a globally important group of cyanobacteria, thrives in various light niches in part due to its varied photosynthetic light-harvesting pigments. Many Synechococcus strains use a process known as chromatic acclimation to optimize the ratio of two chromophores, green-light{\textendash}absorbing phycoerythrobilin (PEB) and blue-light{\textendash}absorbing phycourobilin (PUB), within their light-harvesting complexes. A full mechanistic understanding of how Synechococcus cells tune their PEB to PUB ratio during chromatic acclimation has not yet been obtained. Here, we show that interplay between two enzymes named MpeY and MpeZ controls differential PEB and PUB covalent attachment to the same cysteine residue. MpeY attaches PEB to the light-harvesting protein MpeA in green light, while MpeZ attaches PUB to MpeA in blue light. We demonstrate that the ratio of mpeY to mpeZ mRNA determines if PEB or PUB is attached. Additionally, strains encoding only MpeY or MpeZ do not acclimate. Examination of strains of Synechococcus isolated from across the globe indicates that the interplay between MpeY and MpeZ uncovered here is a critical feature of chromatic acclimation for marine Synechococcus worldwide.}, keywords = {RCC1086, RCC2035, rcc2380, rcc2382, RCC2385, RCC2433, RCC2437, RCC2528, RCC2533, RCC2534, RCC2535, RCC2571, RCC2673, RCC28, RCC307, RCC328, RCC515, rcc555, rcc791}, issn = {0027-8424}, doi = {10.1073/pnas.1810491116}, url = {http://www.pnas.org/lookup/doi/10.1073/pnas.1810491116}, author = {Sanfilippo, Joseph E. and Nguyen, Adam A. and Garczarek, Laurence and Karty, Jonathan A. and Pokhrel, Suman and Strnat, Johann A. and Partensky, Fr{\'e}d{\'e}ric and Schluchter, Wendy M. and Kehoe, David M.} } @article {Breton2019, title = {Unveiling membrane thermoregulation strategies in marine picocyanobacteria}, journal = {New Phytologist}, number = {July}, year = {2019}, note = {ISBN: 0000000244022 tex.mendeley-tags: RCC2374,RCC2385,RCC515,RCC539}, month = {oct}, pages = {nph.16239}, keywords = {RCC2374, RCC2385, RCC515, rcc539}, issn = {0028-646X}, doi = {10.1111/nph.16239}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/nph.16239}, author = {Breton, Sol{\`e}ne and Jouhet, Juliette and Guyet, Ulysse and Gros, Val{\'e}rie and Pittera, Justine and Demory, David and Partensky, Fr{\'e}d{\'e}ric and Dor{\'e}, Hugo and Ratin, Morgane and Mar{\'e}chal, {\'E}ric and Nguyen, Ngoc An and Garczarek, Laurence and Six, Christophe} } @article {Partensky2018, title = {Comparison of photosynthetic performances of marine picocyanobacteria with different configurations of the oxygen-evolving complex}, journal = {Photosynthesis Research}, volume = {138}, number = {1}, year = {2018}, note = {tex.mendeley-tags: RCC752}, pages = {57{\textendash}71}, 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.}, keywords = {rcc752}, issn = {1573-5079}, doi = {10.1007/s11120-018-0539-3}, url = {https://doi.org/10.1007/s11120-018-0539-3}, author = {Partensky, Fr{\'e}d{\'e}ric and Mella-Flores, Daniella and Six, Christophe and Garczarek, Laurence and Czjzek, Mirjam and Marie, Dominique and Kotabov{\'a}, Eva and Felcmanov{\'a}, Kristina and Pr{\'a}{\v s}il, Ond{\v r}ej} } @article {Grebert2018, title = {Light color acclimation is a key process in the global ocean distribution of Synechococcus cyanobacteria}, journal = {Proceedings of the National Academy of Sciences}, volume = {in press}, year = {2018}, note = {tex.mendeley-tags: 2018,RCC1016,RCC1017,RCC1018,RCC1020,RCC1023,RCC1027,RCC1030,RCC1031,RCC1084,RCC1085,RCC1086,RCC1087,RCC1096,RCC1097,RCC1649,RCC1661,RCC1688,RCC2032,RCC2033,RCC2035,RCC2319,RCC2366,RCC2368,RCC2369,RCC2370,RCC2372,RCC2373,RCC2374,RCC2375,RCC2376,RCC2378,RCC2379,RCC2380,RCC2381,RCC2382,RCC2383,RCC2384,RCC2385,RCC2415,RCC2432,RCC2433,RCC2434,RCC2435,RCC2436,RCC2437,RCC2438,RCC2457,RCC2525,RCC2526,RCC2527,RCC2528,RCC2529,RCC2530,RCC2532,RCC2533,RCC2534,RCC2536,RCC2553,RCC2554,RCC2555,RCC2556,RCC2567,RCC2568,RCC2569,RCC2570,RCC2571,RCC2673,RCC30,RCC3010,RCC3012,RCC3014,RCC307,RCC316,RCC318,RCC325,RCC326,RCC328,RCC37,RCC44,RCC46,RCC47,RCC515,RCC539,RCC542,RCC543,RCC550,RCC552,RCC553,RCC555,RCC556,RCC557,RCC558,RCC559,RCC62,RCC650,RCC66,RCC752,RCC753,RCC790,RCC791,RCC792,RCC793,RCC794,sbr?hyto?app}, month = {feb}, pages = {201717069}, abstract = {Marine Synechococcus cyanobacteria are major contributors to global oceanic primary production and exhibit a unique diversity of photosynthetic pigments, allowing them to exploit a wide range of light niches. However, the relationship between pigment content and niche partitioning has remained largely undetermined so far due to the lack of a single-genetic marker resolving all pigment types (PT). Here, we developed a novel and robust method based on three distinct marker genes to estimate the relative abundance of all Synechococcus PTs from metagenomes. Analysis of the Tara Oceans dataset allowed us to unveil for the first time the global distribution of Synechococcus PTs and to decipher their realized environmental niches. Green-light specialists (PT 3a) dominated in warm, green equatorial waters, whereas blue-light specialists (PT 3c) were particularly abundant in oligotrophic areas. Type IV chromatic acclimaters (CA4-A/B), which are able to dynamically modify their light absorption properties to maximally absorb green or blue light, were unexpectedly the most abundant PT in our dataset and predominated at depth and high latitudes. We also identified local populations in which CA4 might be inactive due to the lack of specific CA4 genes, notably in warm high nutrient low chlorophyll areas. Major ecotypes within clades I-IV and CRD1 were preferentially associated with a particular PT, while others exhibited a wide range of PTs. Altogether, this study brings unprecedented insights into the ecology of Synechococcus PTs and highlights the complex interactions between vertical phylogeny, pigmentation and environmental parameters that shape Synechococcus populations and evolution.}, keywords = {2018, RCC1016, RCC1017, RCC1018, RCC1020, RCC1023, RCC1027, RCC1030, RCC1031, rcc1084, RCC1085, RCC1086, RCC1087, RCC1096, RCC1097, RCC1649, RCC1661, RCC1688, RCC2032, RCC2033, RCC2035, RCC2319, RCC2366, RCC2368, RCC2369, RCC2370, RCC2372, RCC2373, RCC2374, RCC2375, RCC2376, RCC2378, RCC2379, rcc2380, RCC2381, rcc2382, RCC2383, RCC2384, RCC2385, RCC2415, RCC2432, RCC2433, RCC2434, RCC2435, RCC2436, RCC2437, RCC2438, RCC2457, RCC2525, RCC2526, RCC2527, RCC2528, RCC2529, RCC2530, RCC2532, RCC2533, RCC2534, RCC2536, RCC2553, RCC2554, RCC2555, RCC2556, RCC2567, RCC2568, RCC2569, RCC2570, RCC2571, RCC2673, rcc30, RCC3010, RCC3012, RCC3014, RCC307, RCC316, RCC318, RCC325, RCC326, RCC328, RCC37, RCC44, RCC46, RCC47, RCC515, rcc539, RCC542, RCC543, RCC550, RCC552, RCC553, rcc555, RCC556, RCC557, RCC558, RCC559, RCC62, RCC650, RCC66, rcc752, RCC753, RCC790, rcc791, RCC792, RCC793, RCC794, sbr?hyto?app}, issn = {0027-8424}, doi = {10.1073/pnas.1717069115}, url = {http://www.pnas.org/lookup/doi/10.1073/pnas.1717069115}, author = {Gr{\'e}bert, Th{\'e}ophile and Dor{\'e}, Hugo and Partensky, Fr{\'e}d{\'e}ric and Farrant, Gregory K. and Boss, Emmanuel S. and Picheral, Marc and Guidi, Lionel and Pesant, St{\'e}phane and Scanlan, David J. and Wincker, Patrick and Acinas, Silvia G. and Kehoe, David M. and Garczarek, Laurence} } @article {Partensky2018, title = {A novel species of the marine cyanobacterium Acaryochloris with a unique pigment content and lifestyle}, journal = {Scientific Reports}, volume = {8}, number = {1}, year = {2018}, note = {tex.mendeley-tags: RCC1774}, month = {dec}, pages = {9142}, keywords = {RCC1774}, issn = {2045-2322}, doi = {10.1038/s41598-018-27542-7}, url = {http://www.nature.com/articles/s41598-018-27542-7}, author = {Partensky, Fr{\'e}d{\'e}ric and Six, Christophe and Ratin, Morgane and Garczarek, Laurence and Vaulot, Daniel and Probert, Ian and Calteau, Alexandra and Gourvil, Priscillia and Marie, Dominique and Gr{\'e}bert, Th{\'e}ophile and Bouchier, Christiane and Le Panse, Sophie and Gachenot, Martin and Rodr{\'\i}guez, Francisco and Garrido, Jos{\'e} L.} } @article {Mahmoud2017, title = {Adaptation to blue light in marine synechococcus requires MpeU, an enzyme with similarity to phycoerythrobilin lyase isomerases}, journal = {Frontiers in Microbiology}, volume = {8}, number = {February}, year = {2017}, note = {tex.mendeley-tags: 2017,rcc555,sbr?hyto?app}, month = {feb}, pages = {243}, abstract = {Marine Synechococcus cyanobacteria have successfully adapted to environments with different light colors, which likely contributes to this genus being the second most abundant photosynthetic microorganism worldwide. Populations of Synechococcus that grow in deep, blue ocean waters contain large amounts of the blue-light absorbing chromophore phycourobilin (PUB) in their light harvesting complexes (phycobilisomes). Here we show that all Synechococcus strains adapted to blue light possess a gene called mpeU. MpeU is structurally similar to phycobilin lyases, enzymes that ligate chromophores to phycobiliproteins. Interruption of mpeU caused a reduction in PUB content, produced impaired phycobilisomes and reduced growth rate more strongly in blue than green light. When mpeU was reintroduced in the mpeU mutant background, the mpeU-less phenotype was complemented in terms of PUB content and phycobilisome content. Fluorescence spectra of mpeU mutant cells and purified phycobilisomes revealed red-shifted phycoerythrin emission peaks, likely indicating a defect in chromophore ligation to phycoerythrin-I (PE-I) or phycoerythrin-II (PE-II). Our results suggest that MpeU is a lyase-isomerase that attaches a phycoerythrobilin to a PEI or PEII subunit and isomerizes it to PUB. MpeU is therefore an important determinant in adaptation of Synechococcus spp. to capture photons in blue light environments throughout the world{\textquoteright}s oceans.}, keywords = {2017, Blue light, light harvesting complex, Lyase isomerase, marine cyanobacteria, Marine Synechococcus, phycobilin, Phycobilisome, Phycoerythrin, Phycourobilin, rcc555, sbr?hyto?app}, issn = {1664-302X}, doi = {10.3389/fmicb.2017.00243}, url = {http://journal.frontiersin.org/article/10.3389/fmicb.2017.00243/full}, author = {Mahmoud, Rania M. and Sanfilippo, Joseph E. and Nguyen, Adam A. and Strnat, Johann A. and Partensky, Fr{\'e}d{\'e}ric and Garczarek, Laurence and Abo El Kassem, Nabil and Kehoe, David M. and Schluchter, Wendy M.} } @article {Pittera2016, title = {Adaptive thermostability of light-harvesting complexes in marine picocyanobacteria}, journal = {The ISME Journal}, volume = {11}, number = {1}, year = {2017}, note = {tex.mendeley-tags: 2016,rcc1594,rcc1682,rcc2380,rcc2382,rcc752,rcc791}, pages = {112{\textendash}124}, keywords = {2016, rcc1594, rcc1682, rcc2380, rcc2382, rcc752, rcc791}, issn = {1751-7362}, doi = {10.1038/ismej.2016.102}, url = {http://www.nature.com/doifinder/10.1038/ismej.2016.102}, author = {Pittera, Justine and Partensky, Fr{\'e}d{\'e}ric and Six, Christophe} } @article {Cuvelier2017, title = {Responses of the picoprasinophyte Micromonas commoda to light and ultraviolet stress}, journal = {PLOS ONE}, volume = {12}, number = {3}, year = {2017}, note = {ISBN: 1111111111 tex.mendeley-tags: RCC299}, month = {mar}, pages = {e0172135}, keywords = {RCC299}, issn = {1932-6203}, doi = {10.1371/journal.pone.0172135}, url = {http://dx.plos.org/10.1371/journal.pone.0172135}, author = {Cuvelier, Marie L and Guo, Jian and Ortiz, Alejandra C. and van Baren, Marijke J. and Tariq, Muhammad Akram and Partensky, Fr{\'e}d{\'e}ric and Worden, Alexandra Z}, editor = {Cockshutt, Amanda M.} } @article {Humily2013, title = {A gene island with two possible configurations is involved in chromatic acclimation in marine synechococcus}, journal = {PLoS ONE}, volume = {8}, number = {12}, year = {2013}, note = {Publisher: Public Library of Science tex.mendeley-tags: 2013,macumba,rcc,sbr?hyto?app}, pages = {e84459}, abstract = {{\textexclamdown}p{\textquestiondown}{\textexclamdown}italic{\textquestiondown}Synechococcus{\textexclamdown}/italic{\textquestiondown}, 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 {\textexclamdown}italic{\textquestiondown}Synechococcus{\textexclamdown}/italic{\textquestiondown} radiation. A specific gene island was identified in all CA4-performing strains, containing two genes ({\textexclamdown}italic{\textquestiondown}fciA{\textexclamdown}/italic{\textquestiondown}/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 {\textexclamdown}italic{\textquestiondown}mpeZ{\textexclamdown}/italic{\textquestiondown} gene, encoding a recently characterized phycoerythrobilin lyase-isomerase, and a third, small, possible regulator called {\textexclamdown}italic{\textquestiondown}fciC{\textexclamdown}/italic{\textquestiondown}. In CA4-B islands, the lyase gene encodes an uncharacterized relative of MpeZ, called MpeW. While {\textexclamdown}italic{\textquestiondown}mpeZ{\textexclamdown}/italic{\textquestiondown} is expressed more in blue light than green light, this is the reverse for {\textexclamdown}italic{\textquestiondown}mpeW{\textexclamdown}/italic{\textquestiondown}, 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.{\textexclamdown}/p{\textquestiondown}}, keywords = {2013, MACUMBA, MicroB3, rcc, SBR$_\textrmP$hyto$_\textrmP$PM, sbr?hyto?app}, doi = {10.1371/journal.pone.0084459}, url = {http://dx.doi.org/10.1371/journal.pone.0084459}, author = {Humily, Florian and Partensky, Fr{\'e}d{\'e}ric and Six, Christophe and Farrant, Gregory K and Ratin, Morgane and Marie, Dominique and Garczarek, Laurence} } @article {Collen2013, title = {Genome structure and metabolic features in the red seaweed Chondrus crispus shed light on evolution of the Archaeplastida}, journal = {Proceedings of the National Academy of Sciences}, volume = {110}, number = {13}, year = {2013}, note = {tex.mendeley-tags: RCC299}, pages = {5247{\textendash}5252}, abstract = {Red seaweeds are key components of coastal ecosystems and are economically important as food and as a source of gelling agents, but their genes and genomes have received little attention. Here we report the sequencing of the 105-Mbp genome of the florideophyte Chondrus crispus (Irish moss) and the annotation of the 9,606 genes. The genome features an unusual structure characterized by gene-dense regions surrounded by repeat-rich regions dominated by transposable elements. Despite its fairly large size, this genome shows features typical of compact genomes, e.g., on average only 0.3 introns per gene, short introns, low median distance between genes, small gene families, and no indication of large-scale genome duplication. The genome also gives insights into the metabolism of marine red algae and adaptations to the marine environment, including genes related to halogen metabolism, oxylipins, and multicellularity (microRNA processing and transcription factors). Particularly interesting are features related to carbohydrate metabolism, which include a minimalistic gene set for starch biosynthesis, the presence of cellulose synthases acquired before the primary endosymbiosis showing the polyphyly of cellulose synthesis in Archaeplastida, and cellulases absent in terrestrial plants as well as the occurrence of a mannosylglycerate synthase potentially originating from a marine bacterium. To explain the observations on genome structure and gene content, we propose an evolutionary scenario involving an ancestral red alga that was driven by early ecological forces to lose genes, introns, and intergenetic DNA; this loss was followed by an expansion of genome size as a consequence of activity of transposable elements.}, keywords = {RCC299}, doi = {10.1073/pnas.1221259110}, url = {http://www.pnas.org/content/110/13/5247.abstract}, author = {Collen, Jonas and Porcel, Betina and Carr{\'e}, Wilfrid and Ball, Steven G and Chaparro, Cristian and Tonon, Thierry and Barbeyron, Tristan and Michel, Gurvan and Noel, Benjamin and Valentin, Klaus and Elias, Marek and Artiguenave, Fran{\c c}ois and Arun, Alok and Aury, Jean-Marc and Barbosa-Neto, Jos{\'e} F and Bothwell, John H and Bouget, Fran{\c c}ois-Yves and Brillet, Loraine and Cabello-Hurtado, Francisco and Capella-Guti{\'e}rrez, Salvador and Charrier, B{\'e}n{\'e}dicte and Cladi{\`e}re, Lionel and Cock, J Mark and Coelho, Susana M and Colleoni, Christophe and Czjzek, Mirjam and Da Silva, Corinne and Delage, Ludovic and Denoeud, France and Deschamps, Philippe and Dittami, Simon M and Gabald{\'o}n, Toni and Gachon, Claire M M and Groisillier, Agn{\`e}s and Herv{\'e}, C{\'e}cile and Jabbari, Kamel and Katinka, Michael and Kloareg, Bernard and Kowalczyk, Nathalie and Labadie, Karine and Leblanc, Catherine and Lopez, Pascal J and McLachlan, Deirdre H and Meslet-Cladiere, Laurence and Moustafa, Ahmed and Nehr, Zofia and Nyvall Coll{\'e}n, Pi and Panaud, Olivier and Partensky, Fr{\'e}d{\'e}ric and Poulain, Julie and Rensing, Stefan A and Rousvoal, Sylvie and Samson, Gaelle and Symeonidi, Aikaterini and Weissenbach, Jean and Zambounis, Antonios and Wincker, Patrick and Boyen, Catherine} } @article {Sharon2009, title = {Photosystem I gene cassettes are present in marine virus genomes}, journal = {Nature}, volume = {461}, number = {7261}, year = {2009}, note = {Publisher: Macmillan Publishers Limited. All rights reserved tex.mendeley-tags: RCC307}, pages = {258{\textendash}262}, keywords = {RCC307, SBR$_\textrmP$hyto$_\textrmP$PM}, doi = {10.1038/nature08284}, url = {http://dx.doi.org/10.1038/nature08284 http://www.nature.com/nature/journal/v461/n7261/suppinfo/nature08284_S1.html}, author = {Sharon, Itai and Alperovitch, Ariella and Rohwer, Forest and Haynes, Matthew and Glaser, Fabian and Atamna-Ismaeel, Nof and Pinter, Ron Y and Partensky, Fr{\'e}d{\'e}ric and Koonin, Eugene V and Wolf, Yuri I and Nelson, Nathan and B{\'e}j{\`a}, Oded} } @article {Derelle2006, title = {Genome analysis of the smallest free-living eukaryote Ostreococcus tauri unveils many unique features}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {103}, number = {31}, year = {2006}, note = {tex.mendeley-tags: RCC745}, pages = {11647{\textendash}11652}, abstract = {The green lineage is reportedly 1,500 million years old, evolving shortly after the endosymbiosis event that gave rise to early photosynthetic eukaryotes. In this study, we unveil the complete genome sequence of an ancient member of this lineage, the unicellular green alga Ostreococcus tauri (Prasinophyceae). This cosmopolitan marine primary producer is the world{\textquoteright}s smallest free-living eukaryote known to date. Features likely reflecting optimization of environmentally relevant pathways, including resource acquisition, unusual photosynthesis apparatus, and genes potentially involved in C4 photosynthesis, were observed, as was downsizing of many gene families. Overall, the 12.56-Mb nuclear genome has an extremely high gene density, in part because of extensive reduction of intergenic regions and other forms of compaction such as gene fusion. However, the genome is structurally complex. It exhibits previously unobserved levels of heterogeneity for a eukaryote. Two chromosomes differ structurally from the other eighteen. Both have a significantly biased G+C content, and, remarkably, they contain the majority of transposable elements. Many chromosome 2 genes also have unique codon usage and splicing, but phylogenetic analysis and composition do not support alien gene origin. In contrast, most chromosome 19 genes show no similarity to green lineage genes and a large number of them are specialized in cell surface processes. Taken together, the complete genome sequence, unusual features, and downsized gene families, make O. tauri an ideal model system for research on eukaryotic genome evolution, including chromosome specialization and green lineage ancestry.}, keywords = {rcc, RCC745, SBR$_\textrmP$hyto}, doi = {10.1073/pnas.0604795103}, url = {http://www.pnas.org/cgi/content/abstract/103/31/11647}, author = {Derelle, Evelyne and Ferraz, Conchita and Rombauts, Stephane and Rouze, Pierre and Worden, Alexandra Z and Robbens, Steven and Partensky, Fr{\'e}d{\'e}ric and Degroeve, Sven and Echeynie, Sophie and Cooke, Richard and Saeys, Yvan and Wuyts, Jan and Jabbari, Kamel and Bowler, Chris and Panaud, Olivier and Piegu, Benoit and Ball, Steven G and Ral, Jean-Philippe and Bouget, Fran{\c c}ois-Yves and Piganeau, Gwenael and De Baets, Bernard and Picard, Andr{\'e} and Delseny, Michel and Demaille, Jacques and Van de Peer, Yves and Moreau, Herv{\'e}} } @article {Six2005, title = {Two novel phycoerythrin-associated linker proteins in the marine cyanobacterium synechococcus sp. Strain WH8102}, journal = {Journal of Bacteriology}, volume = {187}, number = {5}, year = {2005}, note = {tex.mendeley-tags: 2005,rcc,sbr?hyto}, pages = {1685{\textendash}1694}, abstract = {The recent availability of the whole genome of Synechococcus sp. strain WH8102 allows us to have a global view of the complex structure of the phycobilisomes of this marine picocyanobacterium. Genomic analyses revealed several new characteristics of these phycobilisomes, consisting of an allophycocyanin core and rods made of one type of phycocyanin and two types of phycoerythrins (I and II). Although the allophycocyanin appears to be similar to that found commonly in freshwater cyanobacteria, the phycocyanin is simpler since it possesses only one complete set of alpha and beta subunits and two rod-core linkers (CpcG1 and CpcG2). It is therefore probably made of a single hexameric disk per rod. In contrast, we have found two novel putative phycoerythrin-associated linker polypeptides that appear to be specific for marine Synechococcus spp. The first one (SYNW2000) is unusually long (548 residues) and apparently results from the fusion of a paralog of MpeC, a phycoerythrin II linker, and of CpeD, a phycoerythrin-I linker. The second one (SYNW1989) has a more classical size (300 residues) and is also an MpeC paralog. A biochemical analysis revealed that, like MpeC, these two novel linkers were both chromophorylated with phycourobilin. Our data suggest that they are both associated (partly or totally) with phycoerythrin II, and we propose to name SYNW2000 and SYNW1989 MpeD and MpeE, respectively. We further show that acclimation of phycobilisomes to high light leads to a dramatic reduction of MpeC, whereas the two novel linkers are not significantly affected. Models for the organization of the rods are proposed.}, keywords = {2005, rcc, SBR$_\textrmP$hyto, sbr?hyto}, doi = {10.1128/JB.187.5.1685-1694.2005}, url = {http://jb.asm.org/cgi/content/abstract/187/5/1685}, author = {Six, Christophe and Thomas, Jean-Claude and Thion, Laurent and Lemoine, Yves and Zal, Frank and Partensky, Fr{\'e}d{\'e}ric} } @article {Fuller2003, title = {Clade-specific 16S ribosomal DNA oligonucleotides reveal the predominance of a single marine Synechococcus clade throughout a stratified water column in the Red Sea}, journal = {Applied and Environmental Microbiology}, volume = {69}, number = {5}, year = {2003}, note = {tex.mendeley-tags: 2003,rcc,sbr?hyto}, pages = {2430{\textendash}2443}, abstract = {Phylogenetic relationships among members of the marine Synechococcus genus were determined following sequencing of the 16S ribosomal DNA (rDNA) from 31 novel cultured isolates from the Red Sea and several other oceanic environments. This revealed a large genetic diversity within the marine Synechococcus cluster consistent with earlier work but also identified three novel clades not previously recognized. Phylogenetic analyses showed one clade, containing halotolerant isolates lacking phycoerythrin (PE) and including strains capable, or not, of utilizing nitrate as the sole N source, which clustered within the MC-A (Synechococcus subcluster 5.1) lineage. Two copies of the 16S rRNA gene are present in marine Synechococcus genomes, and cloning and sequencing of these copies from Synechococcus sp. strain WH 7803 and genomic information from Synechococcus sp. strain WH 8102 reveal these to be identical. Based on the 16S rDNA sequence information, clade-specific oligonucleotides for the marine Synechococcus genus were designed and their specificity was optimized. Using dot blot hybridization technology, these probes were used to determine the in situ community structure of marine Synechococcus populations in the Red Sea at the time of a Synechococcus maximum during April 1999. A predominance of genotypes representative of a single clade was found, and these genotypes were common among strains isolated into culture. Conversely, strains lacking PE, which were also relatively easily isolated into culture, represented only a minor component of the Synechococcus population. Genotypes corresponding to well-studied laboratory strains also appeared to be poorly represented in this stratified water column in the Red Sea.}, keywords = {2003, PICODIV, rcc, SBR$_\textrmP$hyto, sbr?hyto}, issn = {0099-2240}, doi = {10.1128/AEM.69.5.2430-2443.2003}, url = {http://aem.asm.org/cgi/content/abstract/69/5/2430}, author = {Fuller, Nicholas J and Marie, Dominique and Partensky, Fr{\'e}d{\'e}ric and Vaulot, Daniel and Post, Anton F and Scanlan, David J} }