@article {florenza_choice_2023, title = {Choice of methodology and surrogate prey are decisive for the quality of protistan bacterivory rate estimates}, journal = {Aquatic Microbial Ecology}, volume = {89}, year = {2023}, month = {mar}, pages = {43{\textendash}53}, abstract = {Microeukaryote predation on bacteria is a fundamental phenomenon to understand energy and nutrient dynamics at the base of the aquatic food web. To date, the most prevalent way to estimate grazing rates is by using epifluorescence microscopy to enumerate ingestion events of fluorescently labelled tracers (FLTs) after short-term incubation experiments. However, this approach can be sensitive to the type of FLT, requires skillful preparation of the samples and is limited to small sample sizes. We tested the susceptibility of rate estimates to the choice of prey and made a side-by-side comparison between microscopy and flow cytometry when recording ingestion by a bacterivorous flagellate. Short-term uptake experiments were established using 5 types of FLTs differing in quality (living, dead or inert) and size (large or small), with Ochromonas triangulata as a model flagellate. The experiments showed that (1) each of the different prey types yielded different clearing rates, ranging from 0.5 to 3.6 nl cell-1 h-1, with the largest differences (3fold or higher) between small prey (lower rates) and large prey (higher rates); (2) the cytometry estimate differed significantly from the microscopy estimate in 3 out of 4 experimental configurations; and (3) the precision of the cytometric analysis was greater, with > 3-fold higher uncertainty associated with microscopy counting. Our results validate that flow cytometry provides a more precise bacterivory estimate, and that the choice of FLT influences the grazing rate estimate to a high extent regardless of the analytical method used.}, keywords = {RCC21}, issn = {0948-3055, 1616-1564}, doi = {10.3354/ame01996}, url = {https://www.int-res.com/abstracts/ame/v89/p43-53/}, author = {Florenza, J and Bertilsson, S} } @booklet {clark_coccolithophorids_2023, title = {Coccolithophorids precipitate carbonate in clumped isotope equilibrium with seawater}, year = {2023}, month = {nov}, publisher = {EGUsphere}, type = {preprint}, abstract = {Numerous recent studies have tested the clumped isotope (Δ47) thermometer on a variety of biogenic carbonates such as foraminifera and bivalves and showed that all follow a common calibration. While the sample size requirements for a reliable Δ47 measurement have decreased over the years, the availability and preservation of many biogenic carbonates is still 10 limited and/or require substantial time to be extracted from sediments in sufficient amounts. We thus determined the Δ47temperature relationship for coccolith carbonate, which is abundant and often well-preserved in sediments. The carbon and oxygen isotopic compositions of coccolith calcite have limited use in palaeoenvironmental reconstructions due to physiological effects that cause variability in the carbon and oxygen isotopic values. However, the relatively limited data available suggest that clumped isotopes may not be influenced by these effects. We cultured three species of coccolithophores in well15 constrained carbonate system conditions with a CO2(aq) between 5 and 45 μM and temperatures between 6{\textdegree}C and 27{\textdegree}C.}, keywords = {RCC1130, RCC1303, RCC3370}, doi = {10.5194/egusphere-2023-2581}, url = {https://egusphere.copernicus.org/preprints/2023/egusphere-2023-2581/}, author = {Clark, Alexander J. and Torres-Romero, Ismael and Jaggi, Madalina and Bernasconi, Stefano M. and Stoll, Heather M.} } @article {arnaldo_comparison_2023, title = {Comparison of different small-scale cultivation methods towards the valorization of a marine benthic diatom strain for lipid production}, journal = {Algal Research}, year = {2023}, pages = {103327}, keywords = {RCC5813}, issn = {22119264}, doi = {10.1016/j.algal.2023.103327}, url = {https://linkinghub.elsevier.com/retrieve/pii/S2211926423003600}, author = {Arnaldo, Mary Dianne Grace and Gamage, Nadeeshani Dehel and Jaffrenou, Agathe and Rabesaotra, Vony and Mossion, Aur{\'e}lie and Wielgosz-Collin, Ga{\"e}tane and M{\'e}l{\'e}der, Vona} } @article {edullantes_comparison_2023, title = {Comparison of thermal traits between non-toxic and potentially toxic marine phytoplankton: Implications to their responses to ocean warming}, journal = {Journal of Experimental Marine Biology and Ecology}, volume = {562}, year = {2023}, pages = {151883}, abstract = {Understanding the effect of temperature on growth in marine phytoplankton is crucial in predicting the biogeography and phenology of algal blooms in the warming ocean. Here, we investigated the temperature dependence of the growth of non-toxic and potentially toxic marine phytoplankton. Using non-toxic strains (Prorocentrum sp. NRR 188, Prorocentrum micans CCAP 1136/15, and Alexandrium tamutum PARALEX 242) and potentially toxic strains (Prorocentrum minimum Poulet, Prorocentrum lima CCAP 1136/11, and Alexandrium minutum PARALEX 246) of dinoflagellates as test organisms, we measured their growth rates along a wide temperature gradient and estimated their maximum growth rates, thermal traits (e.g. thermal optima (Topt), critical thermal minima (CTmin), critical thermal maximum (CTmax), fundamental thermal niche (FTN), and skewness), thermal sensitivity, and warming vulnerability. To allow a comparison of these traits with an adequate number of observations, we independently analyzed datasets compiled from published laboratory experiments. Our experiments revealed that the temperature traits were independent of the toxicity of phytoplankton, except for Topt and CTmax. Also, the results of the analysis of the published datasets showed that maximum growth rates and thermal traits were comparable between non-toxic and potentially toxic phytoplankton. Our findings suggest that non-toxic and potentially toxic phytoplankton have generally comparable temperature traits that they can use to respond to climate change. However, depending on the climate scenario, non-toxic phytoplankton may be more vulnerable to warming than potentially toxic phytoplankton. Further studies are needed to improve our understanding of the response of marine phytoplankton to temperature, which can advance our ability to predict algal blooms in response to ongoing climate change.}, keywords = {Growth experiment, Growth models, Microalgal ecophysiology, RCC2649, RCC291, RCC3034, Thermal performance, Thermal physiology, Toxic microalgae}, issn = {0022-0981}, doi = {10.1016/j.jembe.2023.151883}, url = {https://www.sciencedirect.com/science/article/pii/S0022098123000151}, author = {Edullantes, Brisneve and Low-Decarie, Etienne and Steinke, Michael and Cameron, Tom} } @article {graeff_composition_2023, title = {Composition of galactolipids, betaine lipids and triglyceride-associated fatty acids of the symbiotic dinoflagellate Zooxanthella (Brandtodinium) nutricula: A glimpse into polyunsaturated fatty acids available to its polycystine radiolarian host}, journal = {Phycological Research}, volume = {n/a}, number = {n/a}, year = {2023}, note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1111/pre.12530}, abstract = {

Zooxanthella nutricula is a photosynthetic dinoflagellate symbiont of polycystine radiolarians. As such, it is hypothesized to provide fixed organic carbon, including in the form of acylglycerolipids and sterols, to its non-photosynthetic host. We have previously characterized the sterols of Z. nutricula that may be transferred to its host and, in the present study, have turned our attention to three classes of fatty acid-containing lipids, chloroplast-associated galactolipids, betaine lipids, which are non-phosphorylated phospholipid analogs present in many eukaryotes, and triglycerides. Zooxanthella nutricula was observed using positive-ion electrospray/mass spectrometry (ESI/MS) and ESI/MS/MS to produce the galactolipids mono- and digalactosyldiacylglycerol (MGDG and DGDG, respectively) enriched in octadecapentaenoic (18:5(n-3)) and octadecatetraenoic (18:4(n-3)) acid to place it within a group of peridinin-containing dinoflagellates in a C18/C18 (sn-1/sn-2 fatty acid regiochemistry) cluster, as opposed to another cluster with C20/C18 MGDG and DGDG, where the C20 fatty acid is eicosapentaenoic acid (20:5(n-3)) and the C18 fatty acid is either 18:5(n-3) or 18:4(n-3). Zooxanthella nutricula was also observed to produce 38:10 (total number of fatty acid carbons:total number of double bonds), 38:6, and 44:7 diacylglycerylcarboxyhydroxymethylcholine (DGCC) as the sole type of betaine lipid. Although it is more difficult to determine which fatty acids are present in the sn-1 and sn-2 positions on the glycerol backbone of DGCC using ESI/MS/MS, gas chromatography/mass spectrometry (GC/MS)-based examination indicated the putatively DGCC-associated polyunsaturated fatty acid (PUFA) docosahexaenoic acid (22:6(n-3)). Coupled with the C18 PUFAs of MGDG and DGDG, and fatty acids associated with triglycerides (also examined via GC/MS), Z. nutricula could serve as a rich source of PUFAs for its radiolarian host. These data demonstrate that Z. nutricula produces a similar set of PUFA-containing lipids as Symbiodinium microadriaticum, a photosynthetic dinoflagellate symbiont of cnidarians, indicating a metabolic commonality in these phylogenetically discrete dinoflagellate symbionts with unrelated host organisms.

}, keywords = {Brandtodinium, chloroplast, Dinoflagellate, Dinophyceae, lipid, RCC3387, Zooxanthella}, issn = {1440-1835}, doi = {10.1111/pre.12530}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/pre.12530}, author = {Graeff, Jori E. and Leblond, Jeffrey D.} } @booklet {de_vries_critical_2023, title = {A critical trade-off between nitrogen quota and growth allows Coccolithus braarudii life cycle phases{\textquoteright} to exploit varying environment}, year = {2023}, publisher = {Biodiversity and Ecosystem Function: Marine}, type = {preprint}, abstract = {Coccolithophores have a distinct haplo-diplontic life cycle, which allows them to grow and divide in two different life cycle phases (haploid and diploid). These life cycle phases vary significantly in inorganic carbon content and morphology, and inhabit distinct niches, with haploids generally preferring low-nutrient and high-temperature and -light environments. This niche contrast indicates different physiology of the life cycle phases, which is considered here in the context of a trait trade-off 5 framework, in which a particular set of traits comes with both costs and benefits. However, coccolithophore{\textquoteright}s phase trade-offs are not fully identified, limiting our understanding of the functionality of the coccolithophore life cycle. Here, we investigate the response of the two life cycle phases of the coccolithophore Coccolithus braarudii to key environmental drivers: light, temperature and nutrients, using laboratory experiments. With this data, we identify the main trade-offs of each life cycle phase and use models to test the role of such trade-offs under different environmental conditions.}, keywords = {RCC1200, RCC1203, RCC3777, RCC3779, RCC6535}, doi = {10.5194/egusphere-2023-880}, url = {https://egusphere.copernicus.org/preprints/2023/egusphere-2023-880/}, author = {De Vries, Joost and Monteiro, Fanny and Langer, Gerald and Brownlee, Colin and Wheeler, Glen} } @article {ben-joseph_crystallization_2023, title = {Crystallization of Coccolith Calcite at Different Life-Cycle Phases Exhibits Distinct Degrees of Cellular Confinement}, journal = {Small Structures}, volume = {n/a}, number = {n/a}, year = {2023}, note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1002/sstr.202200353}, pages = {2200353}, abstract = {Coccolithophores are a group of unicellular marine algae that shape global geochemical cycles via the production of calcium carbonate crystals. Interestingly, different life-cycle phases of the same coccolithophore species produce very different calcitic scales, called coccoliths. In the widely studied diploid phase, the crystals have anisotropic and complex morphologies, while haploid cells produce coccoliths consisting solely of calcite crystals with simple rhombohedral morphology. Understanding how these two life-cycle phases control crystallization is a highly sought-after goal, yet, haploid phase crystallization has rarely been studied, and the process by which they form is unknown. Herein, advanced electron microscopy is employed to elucidate the cellular architecture of the calcification process in haploid cells. The results show that in contrast to diploid-phase calcification, the coccolith-forming vesicle of haploid-phase cells is voluminous. In this solution-like environment, the crystals nucleate and grow asynchronously in a process that resembles calcite growth in bulk solution, leading to the simple morphologies of the crystals. The two distinct mineralization regimes of coccolithophore life-cycle phases suggest that cellular architecture, and specifically confinement of the crystallization process, is a pivotal determinant of biomineral morphology and assembly.}, keywords = {biomineralization, calcites, Coccoliths, crystal growths, haploid{\textendash}diploid life cycles, RCC1181, RCC3777}, issn = {2688-4062}, doi = {10.1002/sstr.202200353}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/sstr.202200353}, author = {Ben-Joseph, Oz and de Haan, Diede and Rechav, Katya and Shimoni, Eyal and Levin-Zaidman, Smadar and Langer, Gerald and Probert, Ian and Wheeler, Glen L. and Gal, Assaf} } @article {sucheras-marx_coccolith_2022, title = {Coccolith size rules {\textendash} What controls the size of coccoliths during coccolithogenesis?}, journal = {Marine Micropaleontology}, volume = {170}, year = {2022}, pages = {102080}, abstract = {Heterococcoliths are calcite platelets produced inside diploid coccolithophore cells and extruded to form a covering on the cell surface called a coccosphere. The size of coccoliths is an important parameter sometimes used to identify species, and it is observed to be influenced in extant species by abiotic parameters (e.g., CO2, light). However, the variable distribution of coccolith sizes occurring within a single coccosphere questions the mechanisms controlling coccolith size. A relationship between cell/coccosphere size and mean coccolith size was previously identified, called the {\textquotedblleft}coccolithophore size rules{\textquotedblright}. In this study, we query the mechanisms controlling the size of a coccolith during coccolithogenesis. A culture experiment on Gephyrocapsa huxleyi strain RCC1216 shows that coccolithogenesis occurs during the cell growth G1 interphase and newly produced coccoliths get bigger as the cell grows. These observations provide parameters for the development of two numerical models used to simulate the coccolith size distribution within a coccolithophore population. Neither model can accurately reproduce an empirical monoclonal coccolith size distribution, indicating that additional factors influence coccolith size. According to our results, coccolith size is only clearly related to cell size at the time of its formation. We confirm that application of the coccolithophore size rules model should be limited to inferring average cell dimensions from (fossil) coccolith biometry, and that comparisons are valid only in multipopulational studies. The coccolith size rule model {\textendash} the constraining effect of coccolith production during G1 interphase cell growth on coccolith size {\textendash} proposed here is applicable only for some placolith-forming species.}, keywords = {Biometry, coccolith, coccolithophore, life cycle, RCC1216, Size variation}, issn = {0377-8398}, doi = {10.1016/j.marmicro.2021.102080}, url = {https://www.sciencedirect.com/science/article/pii/S0377839821001213}, author = {Such{\'e}ras-Marx, Baptiste and Viseur, Sophie and Walker, Charlotte E. and Beaufort, Luc and Probert, Ian and Bolton, Clara} } @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 {phelps_carbon_2021, title = {Carbon Isotope Fractionation in Noelaerhabdaceae Algae in Culture and a Critical Evaluation of the Alkenone Paleobarometer}, journal = {Geochemistry, Geophysics, Geosystems}, volume = {22}, number = {7}, year = {2021}, note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1029/2021GC009657}, pages = {e2021GC009657}, abstract = {The carbon isotope fractionation in algal organic matter ($\varepsilon$p), including the long-chain alkenones produced by the coccolithophorid family Noelaerhabdaceae, is used to reconstruct past atmospheric CO2 levels. The conventional proxy linearly relates $\varepsilon$p to changes in cellular carbon demand relative to diffusive CO2 supply, with larger $\varepsilon$p values occurring at lower carbon demand relative to supply (i.e., abundant CO2). However, the response of Gephyrocapsa oceanica, one of the dominant alkenone producers of the last few million years, has not been studied closely. Here, we subject G. oceanica to various CO2 levels by increasing pCO2 in the culture headspace, as opposed to increasing dissolved inorganic carbon (DIC) and alkalinity concentrations at constant pH. We note no substantial change in physiology, but observe an increase in $\varepsilon$p as carbon demand relative to supply decreases, consistent with DIC manipulations. We compile existing Noelaerhabdaceae $\varepsilon$p data and show that the diffusive model poorly describes the data. A meta-analysis of individual treatments (unique combinations of lab, strain, and light conditions) shows that the slope of the $\varepsilon$p response depends on the light conditions and range of carbon demand relative to CO2 supply in the treatment, which is incompatible with the diffusive model. We model $\varepsilon$p as a multilinear function of key physiological and environmental variables and find that both photoperiod duration and light intensity are critical parameters, in addition to CO2 and cell size. While alkenone carbon isotope ratios indeed record CO2 information, irradiance and other factors are also necessary to properly describe alkenone $\varepsilon$p.}, keywords = {alkenone, carbon dioxide, carbon isotope, coccolithophore, irradiance, paleobarometry, rcc, RCC1303}, issn = {1525-2027}, doi = {10.1029/2021GC009657}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2021GC009657}, author = {Phelps, Samuel R. and Hennon, Gwenn M. M. and Dyhrman, Sonya T. and Hern{\'a}ndez Lim{\'o}n, Mar{\'\i}a D. and Williamson, Olivia M. and Polissar, Pratigya J.} } @article {alacid_cellcell_2021, title = {A cell{\textendash}cell atlas approach for understanding symbiotic interactions between microbes}, journal = {Current Opinion in Microbiology}, volume = {64}, year = {2021}, pages = {47{\textendash}59}, abstract = {Natural environments are composed of a huge diversity of microorganisms interacting with each other to form complex functional networks. Our understanding of the operative nature of host{\textendash}symbiont associations is limited because propagating such associations in a laboratory is challenging. The advent of single-cell technologies applied to, for example, animal cells and apicomplexan parasites has revolutionized our understanding of development and disease. Such cell atlas approaches generate maps of cell-specific processes and variations within cellular populations. These methods can now be combined with cellular-imaging so that interaction stage versus transcriptome state can be quantized for microbe-microbe interactions. We predict that the combination of these methods applied to the study of symbioses will transform our understanding of many ecological interactions, including those sampled directly from natural environments.}, issn = {1369-5274}, doi = {10.1016/j.mib.2021.09.001}, url = {https://www.sciencedirect.com/science/article/pii/S1369527421001144}, author = {Alacid, Elisabet and Richards, Thomas A} } @article {thomy_combining_2021, title = {Combining Nanopore and Illumina Sequencing Permits Detailed Analysis of Insertion Mutations and Structural Variations Produced by PEG-Mediated Transformation in Ostreococcus tauri}, journal = {Cells}, volume = {10}, number = {3}, year = {2021}, pages = {664}, abstract = {Ostreococcus tauri is a simple unicellular green alga representing an ecologically important group of phytoplankton in oceans worldwide. Modern molecular techniques must be developed in order to understand the mechanisms that permit adaptation of microalgae to their environment. We present for the first time in O. tauri a detailed characterization of individual genomic integration events of foreign DNA of plasmid origin after PEG-mediated transformation. Vector integration occurred randomly at a single locus in the genome and mainly as a single copy. Thus, we confirmed the utility of this technique for insertional mutagenesis. While the mechanism of double-stranded DNA repair in the O. tauri model remains to be elucidated, we clearly demonstrate by genome resequencing that the integration of the vector leads to frequent structural variations (deletions/insertions and duplications) and some chromosomal rearrangements in the genome at the insertion loci. Furthermore, we often observed variations in the vector sequence itself. From these observations, we speculate that a nonhomologous end-joining-like mechanism is employed during random insertion events, as described in plants and other freshwater algal models. PEG-mediated transformation is therefore a promising molecular biology tool, not only for functional genomic studies, but also for biotechnological research in this ecologically important marine alga.}, keywords = {RCC1115, RCC7079, RCC7080, RCC7081, RCC7082, RCC7083, RCC7084, RCC7085}, issn = {2073-4409}, doi = {10.3390/cells10030664}, url = {https://www.mdpi.com/2073-4409/10/3/664}, author = {Thomy, Julie and Sanchez, Fr{\'e}d{\'e}ric and Gut, Marta and Cruz, Fernando and Alioto, Tyler and Piganeau, Gwenael and Grimsley, Nigel and Yau, Sheree} } @booklet {thomy_combining_2021, title = {Combining Nanopore and Illumina Sequencing Permits Detailed Analysis of Insertion Mutations and Structural Variations Produced by PEG-Mediated Transformation in Ostreococcus tauri}, year = {2021}, month = {feb}, publisher = {LIFE SCIENCES}, type = {preprint}, abstract = {Ostreococcus tauri is a simple unicellular green alga representing an ecologically important group of phytoplankton in oceans worldwide. Modern molecular techniques must be developed in order to understand the mechanisms that permit adaptation of microalgae to their environment. We present for the first time in O. tauri a detailed characterization of individual genomic integration events of foreign DNA of plasmid origin after PEG-mediated transformation. Vector integration appears to be random, occurring mainly at a single locus, and thus confirming the utility of this technique for insertional mutagenesis. While the mechanism of double-stranded DNA repair in the O. tauri model remains to be elucidated, we clearly demonstrate by genome resequencing that the integration of the vector leads to frequent structural variations (deletions/insertions and duplications) and some chromosomal rearrangements in the genome at the insertion loci, and often within the vector sequence itself. From these observations, we speculate that a non-homologous end joining-like mechanism is required during random insertion events, as described in plants and other freshwater algal models. PEG-mediated transformation is therefore a promising molecular biology tool, not only for functional genomic studies, but also for biotechnological research in ecologically important marine algae.}, keywords = {RCC1115}, doi = {10.20944/preprints202102.0506.v1}, url = {https://www.preprints.org/manuscript/202102.0506/v1}, author = {Thomy, Julie and Sanchez, Fr{\'e}d{\'e}ric and Gut, Marta and Cruz, Fernando and Alioto, Tyler and Piganeau, Gwenael and Grimsley, Nigel and Yau, Sheree} } @article {fernandes_comparative_2021, title = {Comparative lipidomic analysis of Chlorella stigmatophora and Hemiselmis cf. andersenii in response to nitrogen-induced changes}, journal = {Algal Research}, volume = {58}, year = {2021}, pages = {102417}, abstract = {The current focus of algae biotechnology is the production of high-value lipids, and its improvement by employing abiotic perturbations such as nitrogen-induced changes. In the present study, the growth dynamics, nitrogen uptake, pigments, and lipid composition of Chlorellla stigmatophora and Hemiselmis cf. andersenii were studied, in response to low (LN), medium (MN) and high (HN) nitrogen supplementations. Both microalgae responded to increased nitrogen levels by increasing their nitrogen uptake rate and pigment content. However, for lipid accumulation, C. stigmatophora presented a different pattern (LN: 16.56\% > MN: 11.51\% > HN: 10.95\%) to that of H. cf. andersenii (MN: 15.37\% > HN: 13.06\% > LN: 6.71\%). Untargeted gas chromatography{\textendash}mass spectrometry analysis allowed the visualization of the biochemical diversity of C. stigmatophora and H. cf. andersenii, as well as differences in lipid regulation upon nitrogen-induced changes among species. For instance, glycosyl sterols were only detected for C. stigmatophora samples grown under MN and HN conditions. Moreover, lipid analysis of H. cf. andersenii, before and after alkaline hydrolysis, suggests that wax esters play a key role in the response of this microalga to high nitrogen levels. The cultivation of H. cf. andersenii at MN and HN was shown to be ideal for providing a rich source of ω3 and polyunsaturated fatty acids for nutraceutical purposes. The hierarchical cluster analysis showed the differential intra- and interspecific effects of nitrogen on lipid composition. The diverse ways by which both microalgae responded to nitrogen-induced changes highlighted the influence of phylogeny on the carbon flux through metabolic networks, and accumulation.}, keywords = {cf., Lipidome analysis, Nitrogen supplementation, Nutraceutical lipids, rcc, RCC661}, issn = {2211-9264}, doi = {10.1016/j.algal.2021.102417}, url = {https://www.sciencedirect.com/science/article/pii/S2211926421002368}, author = {Fernandes, Tom{\'a}sia and Ferreira, Artur and Cordeiro, Nereida} } @article {croteau_contrasting_2021, title = {Contrasting nonphotochemical quenching patterns under high light and darkness aligns with light niche occupancy in Arctic diatoms}, journal = {Limnology and Oceanography}, volume = {66}, number = {S1}, year = {2021}, note = {_eprint: https://aslopubs.onlinelibrary.wiley.com/doi/pdf/10.1002/lno.11587}, pages = {S231{\textendash}S245}, abstract = {Over the seasons, Arctic diatom species occupy shifting habitats defined by contrasting light climates, constrained by snow and ice cover dynamics interacting with extreme photoperiod and solar angle variations. How Arctic diatom photoadaptation strategies differ across their heterogeneous light niches remains a poorly documented but crucial missing link to anticipate Arctic Ocean responses to shrinking sea-ice and increasing light. To address this question, we selected five Arctic diatom species with diverse life traits, representative of distinct light niches across the seasonal light environment continuum: from snow-covered dimly lit bottom ice to summer stratified waters. We studied their photoacclimation plasticity to two growth light levels and the subsequent responses of their nonphotochemical quenching (NPQ) and xanthophyll cycle to both dark incubations and light shifts. We deciphered NPQ and xanthophyll cycle tuning in darkness and their light-dependent induction kinetics, which aligned with species{\textquoteright} light niche occupancy. In ice-related species, NPQ was sustained in darkness and its induction was more reactive to moderate light shifts. Open-water species triggered strong NPQ induction in darkness and reached higher maximal NPQ under high light. Marginal ice zone species showed strong adaptation to light fluctuations with a dark response fine-tuned depending upon light history. We argue these traits are anchored in diverging photoadaption strategies fostering Arctic diatom success in their respective light niches.}, keywords = {RCC2046, RCC2278, RCC5318}, issn = {1939-5590}, doi = {10.1002/lno.11587}, url = {https://aslopubs.onlinelibrary.wiley.com/doi/abs/10.1002/lno.11587}, author = {Croteau, Dany and Gu{\'e}rin, S{\'e}bastien and Bruyant, Flavienne and Ferland, Joannie and Campbell, Douglas A. and Babin, Marcel and Lavaud, Johann} } @inbook {Paredes2021, title = {Cryopreservation of algae}, booktitle = {Cryopreservation and freeze-drying protocols}, volume = {2180}, year = {2021}, pages = {607{\textendash}621}, publisher = {Springer Science+Business Media, LLC}, organization = {Springer Science+Business Media, LLC}, keywords = {cryopreservation, macroalgae, Microalgae}, isbn = {978-1-07-160783-1}, doi = {10.1007/978-1-0716-0783-1_32}, url = {http://link.springer.com/10.1007/978-1-0716-0783-1_32}, author = {Paredes, Estefania and Ward, Angela and Probert, Ian and Gouhier, L{\'e}na and Campbell, Christine N.}, editor = {Wolkers, Willem F. and Oldenhof, Harriette} } @article {olusoji_cyanofilter_2021, title = {cyanoFilter: An R package to identify phytoplankton populations from flow cytometry data using cell pigmentation and granularity}, journal = {Ecological Modelling}, volume = {460}, year = {2021}, pages = {109743}, abstract = {Flow cytometry is often employed in ecology to measure traits and population size of bacteria and phytoplankton. This technique allows measuring millions of particles in a relatively small amount of time. However, distinguishing between different populations is not a straightforward task. Gating is a process in the identification of particles measured in flow cytometry. Gates can either be created manually using known characteristics of these particles, or by using automated clustering techniques. Available automated techniques implemented in statistical packages for flow cytometry are primarily developed for medicinal applications, while only two exist for phytoplankton. cyanoFilter is an R package built to identify phytoplankton populations from flow cytometry data. The package also integrates gating functions from two other automated algorithms. It also provides a gating accuracy test function that can be used to determine the accuracy of a desired gating function if monoculture flowcytometry data is available. The central algorithm in the package exploits observed pigmentation and granularity of phytoplankton cells. We demonstrate how its performance depends on strain similarity, using a model system of six cyanobacteria strains. Using the same system, we compare the performance of the central gating function in the package to similar functions in other packages.}, keywords = {Ecology, flow cytometry, Gating, phytoplankton, RCC2375, rcc2380, RCC2434, RCC2555, Software}, issn = {0304-3800}, doi = {10.1016/j.ecolmodel.2021.109743}, url = {https://www.sciencedirect.com/science/article/pii/S030438002100291X}, author = {Olusoji, Oluwafemi D. and Spaak, Jurg W. and Holmes, Mark and Neyens, Thomas and Aerts, Marc and De Laender, Frederik} } @article {fenizia_cysteinolic_2021, title = {Cysteinolic Acid Is a Widely Distributed Compatible Solute of Marine Microalgae}, journal = {Marine Drugs}, volume = {19}, number = {12}, year = {2021}, note = {Number: 12 Publisher: Multidisciplinary Digital Publishing Institute}, month = {dec}, pages = {683}, abstract = {Phytoplankton rely on bioactive zwitterionic and highly polar small metabolites with osmoregulatory properties to compensate changes in the salinity of the surrounding seawater. Dimethylsulfoniopropionate (DMSP) is a main representative of this class of metabolites. Salinity-dependent DMSP biosynthesis and turnover contribute significantly to the global sulfur cycle. Using advanced chromatographic and mass spectrometric techniques that enable the detection of highly polar metabolites, we identified cysteinolic acid as an additional widely distributed polar metabolite in phytoplankton. Cysteinolic acid belongs to the class of marine sulfonates, metabolites that are commonly produced by algae and consumed by bacteria. It was detected in all dinoflagellates, haptophytes, diatoms and prymnesiophytes that were surveyed. We quantified the metabolite in different phytoplankton taxa and revealed that the cellular content can reach even higher concentrations than the ubiquitous DMSP. The cysteinolic acid concentration in the cells of the diatom Thalassiosira weissflogii increases significantly when grown in a medium with elevated salinity. In contrast to the compatible solute ectoine, cysteinolic acid is also found in high concentrations in axenic algae, indicating biosynthesis by the algae and not the associated bacteria. Therefore, we add this metabolite to the family of highly polar metabolites with osmoregulatory characteristics produced by phytoplankton.}, keywords = {cysteinolic acid, diatoms, DMSP, ectoine, LC/MS analysis, osmoadaptation, osmoregulation, phytoplankton, RCC76, salinity}, doi = {10.3390/md19120683}, url = {https://www.mdpi.com/1660-3397/19/12/683}, author = {Fenizia, Simona and Weissflog, Jerrit and Pohnert, Georg} } @article {uwizeye_cytoklepty_2021, title = {Cytoklepty in the plankton: A host strategy to optimize the bioenergetic machinery of endosymbiotic algae}, journal = {Proceedings of the National Academy of Sciences}, volume = {118}, number = {27}, year = {2021}, note = {Publisher: National Academy of Sciences Section: Biological Sciences}, month = {jul}, abstract = {Endosymbioses have shaped the evolutionary trajectory of life and remain ecologically important. Investigating oceanic photosymbioses can illuminate how algal endosymbionts are energetically exploited by their heterotrophic hosts and inform on putative initial steps of plastid acquisition in eukaryotes. By combining three-dimensional subcellular imaging with photophysiology, carbon flux imaging, and transcriptomics, we show that cell division of endosymbionts (Phaeocystis) is blocked within hosts (Acantharia) and that their cellular architecture and bioenergetic machinery are radically altered. Transcriptional evidence indicates that a nutrient-independent mechanism prevents symbiont cell division and decouples nuclear and plastid division. As endosymbiont plastids proliferate, the volume of the photosynthetic machinery volume increases 100-fold in correlation with the expansion of a reticular mitochondrial network in close proximity to plastids. Photosynthetic efficiency tends to increase with cell size, and photon propagation modeling indicates that the networked mitochondrial architecture enhances light capture. This is accompanied by 150-fold higher carbon uptake and up-regulation of genes involved in photosynthesis and carbon fixation, which, in conjunction with a ca.15-fold size increase of pyrenoids demonstrates enhanced primary production in symbiosis. Mass spectrometry imaging revealed major carbon allocation to plastids and transfer to the host cell. As in most photosymbioses, microalgae are contained within a host phagosome (symbiosome), but here, the phagosome invaginates into enlarged microalgal cells, perhaps to optimize metabolic exchange. This observation adds evidence that the algal metamorphosis is irreversible. Hosts, therefore, trigger and benefit from major bioenergetic remodeling of symbiotic microalgae with potential consequences for the oceanic carbon cycle. Unlike other photosymbioses, this interaction represents a so-called cytoklepty, which is a putative initial step toward plastid acquisition.}, keywords = {3D electron microscopy, oceanic plankton, Photosynthesis, rcc, rcc1383, single-cell transcriptomics, symbiosis}, issn = {0027-8424, 1091-6490}, doi = {10.1073/pnas.2025252118}, url = {https://www.pnas.org/content/118/27/e2025252118}, author = {Uwizeye, Clarisse and Brisbin, Margaret Mars and Gallet, Benoit and Chevalier, Fabien and LeKieffre, Charlotte and Schieber, Nicole L. and Falconet, Denis and Wangpraseurt, Daniel and Schertel, Lukas and Stryhanyuk, Hryhoriy and Musat, Niculina and Mitarai, Satoshi and Schwab, Yannick and Finazzi, Giovanni and Decelle, Johan} } @article {Liao2020, title = {C41 methyl and C42 ethyl alkenones are biomarkers for Group II Isochrysidales}, journal = {Organic Geochemistry}, volume = {147}, year = {2020}, note = {Publisher: Elsevier Ltd tex.mendeley-tags: RCC1207,RCC1346,RCC3483}, month = {sep}, pages = {104081}, abstract = {Alkenones are polyunsaturated long-chain methyl or ethyl ketones produced by species in the Isochrysidales, an order of haptophyte algae. Based on phylogenetic data, members of the Isochrysidales have been classified into three groups with each group showing significant differences in alkenone profiles and preferred growth environments. Common carbon chain lengths of alkenones range from 37 to 40. Extended C41 methyl (C41Me) and C42 ethyl (C42Et) alkenones have been reported in hypersaline lakes in China (Lake Alahake and Lake Balikun), Canada (Lake Snakehole) and marine sediments (e.g., \~95 Ma in Blake-Bahama Basin). It is unclear, however, if these extended alkenones are produced by one or more groups of Isochrysidales. Here, we systematically examined alkenones from cultures of Group II (Isochrysis nuda, Isochrysis litoralis, Ruttnera lamellosa, Isochrysis galbana and Tisochrysis lutea) and Group III (Emiliania huxleyi and Gephyrocapsa oceanica) Isochrysidales and environmental samples of Group I Isochysidales. C41Me and C42Et alkenones were found in all Group II species with Isochrysis nuda producing the highest percentages, but not in alkenones produced by Group I nor Group III Isochrysidales. Our results indicate that extended C41Me and C42Et alkenones are specific biomarkers for Group II Isochrysidales. We also report the first temperature calibrations of alkenones for Isochrysis nuda and Isochrysis litoralis using culture experiments, and find temperatures inferred from extended alkenones in Balikun and Alahake surface sediments match warm-season temperatures based on Isochrysis nuda calibrations, which is further corroborated by genomic data indicating the dominance of Isochrysis nuda Isochrysidales.}, keywords = {18S rDNA, Biomarkers, C41 and C42 alkenones, culture, evolution, Isochrysidales, RCC1207, RCC1346, RCC3483}, issn = {01466380}, doi = {10.1016/j.orggeochem.2020.104081}, author = {Liao, Sian and Yao, Yuan and Wang, Li and Wang, Karen J. and Amaral-Zettler, Linda and Longo, William M. and Huang, Yongsong} } @article {Benner2019, title = {Capacity of the common Arctic picoeukaryote Micromonas to adapt to a warming ocean}, journal = {Limnology and Oceanography Letters}, volume = {5}, number = {2}, year = {2020}, note = {tex.mendeley-tags: RCC807}, month = {apr}, pages = {221{\textendash}227}, keywords = {RCC807}, issn = {2378-2242}, doi = {10.1002/lol2.10133}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/lol2.10133}, author = {Benner, Ina and Irwin, Andrew J and Finkel, Zoe V} } @article {Palacio2020, title = {Changes in population age-structure obscure the temperature-size rule in marine cyanobacteria}, journal = {Frontiers in Microbiology}, volume = {11}, year = {2020}, note = {Publisher: Frontiers Media S.A. tex.mendeley-tags: RCC2382,RCC3377}, month = {aug}, pages = {2059}, abstract = {The temperature-size Rule (TSR) states that there is a negative relationship between ambient temperature and body size. This rule has been independently evaluated for different phases of the life cycle in multicellular eukaryotes, but mostly for the average population in unicellular organisms. We acclimated two model marine cyanobacterial strains (Prochlorococcus marinus MIT9301 and Synechococcus sp. RS9907) to a gradient of temperatures and measured the changes in population age-structure and cell size along their division cycle. Both strains displayed temperature-dependent diel changes in cell size, and as a result, the relationship between temperature and average cell size varied along the day. We computed the mean cell size of new-born cells in order to test the prediction of the TSR on a single-growth stage. Our work reconciles previous inconsistent results when testing the TSR on unicellular organisms, and shows that when a single-growth stage is considered the predicted negative response to temperature is revealed.}, keywords = {cell cycle, Cell Division, cell size, Prochlorococcus, rcc2382, RCC3377, Synechococcus, temperature, temperature-size rule}, issn = {1664-302X}, doi = {10.3389/fmicb.2020.02059}, url = {https://www.frontiersin.org/article/10.3389/fmicb.2020.02059/full}, author = {Palacio, Antonio S. and Cabello, Ana Mar{\'\i}a and Garc{\'\i}a, Francisca C. and Labban, Abbrar and Mor{\'a}n, Xos{\'e} Anxelu G. and Garczarek, Laurence and Alonso-S{\'a}ez, Laura and L{\'o}pez-Urrutia, {\'A}ngel} } @article {Mucko2020, title = {Characterization of a lipid-producing thermotolerant marine photosynthetic pico-alga in the genus Picochlorum (Trebouxiophyceae)}, journal = {European Journal of Phycology}, volume = {00}, number = {00}, year = {2020}, note = {Publisher: Taylor \& Francis tex.mendeley-tags: RCC1034,RCC13,RCC14,RCC289,RCC475,RCC6905,RCC846,RCC9,RCC945}, month = {aug}, pages = {1{\textendash}16}, keywords = {morphology, photosynthetic picoeukaryotes, phylogeny, physiology, Picochlorum, RCC1034, RCC13, RCC14, rcc289, RCC475, RCC6905, RCC846, RCC9, RCC945}, issn = {0967-0262}, doi = {10.1080/09670262.2020.1757763}, url = {https://doi.org/10.1080/09670262.2020.1757763 https://www.tandfonline.com/doi/full/10.1080/09670262.2020.1757763}, author = {Mucko, Maja and Padis{\'a}k, Judit and Gligora Udovi{\v c}, Marija and P{\'a}lmai, Tam{\'a}s and Novak, Tihana and Medi{\'c}, Nikola and Ga{\v s}parovi{\'c}, Bla{\v z}enka and Peharec {\v S}tefani{\'c}, Petra and Orli{\'c}, Sandi and Ljube{\v s}i{\'c}, Zrinka} } @article {Carrigee2020, title = {CpeY is a phycoerythrobilin lyase for cysteine 82 of the phycoerythrin I α-subunit in marine Synechococcus}, journal = {Biochimica et Biophysica Acta (BBA) - Bioenergetics}, year = {2020}, note = {Publisher: Elsevier B.V tex.mendeley-tags: RCC555}, month = {apr}, pages = {148215}, keywords = {rcc555}, issn = {00052728}, doi = {10.1016/j.bbabio.2020.148215}, url = {https://doi.org/10.1016/j.bbamem.2019.183135 https://linkinghub.elsevier.com/retrieve/pii/S0005272820300657}, author = {Carrigee, Lyndsay A. and Mahmoud, Rania M. and Sanfilippo, Joseph E. and Frick, Jacob P. and Strnat, Johann A. and Karty, Jonathan A. and Chen, Bo and Kehoe, David M. and Schluchter, Wendy M.} } @article {Cai2020, title = {Cryptic species in the parasitic Amoebophrya species complex revealed by a polyphasic approach}, journal = {Scientific Reports}, volume = {10}, number = {1}, year = {2020}, note = {Publisher: Springer US tex.mendeley-tags: RCC1627,RCC1720,RCC3018,RCC3043,RCC3044,RCC3047,RCC3048,RCC3049,RCC3145,RCC3278,RCC3596,RCC4381,RCC4382,RCC4383,RCC4384,RCC4385,RCC4386,RCC4387,RCC4388,RCC4389,RCC4390,RCC4391,RCC4392,RCC4393,RCC4394,RCC4395,RCC4396,RCC4397,RCC4398,RCC4399,RCC4400,RCC4401,RCC4402,RCC4403,RCC4404,RCC4405,RCC4406,RCC4407,RCC4408,RCC4409,RCC4410,RCC4411,RCC4412,RCC4413,RCC4414,RCC4415,RCC4416,RCC4711,RCC4712,RCC4713,RCC4715,RCC4716,RCC4722,RCC4723,RCC4726,RCC4728,RCC4729,RCC4732,RCC4733,RCC4734,RCC5984,RCC5985,RCC5986,RCC5987,RCC5988,RCC5989,RCC5990,RCC5991,RCC5992,RCC5993,RCC5994,RCC5995,RCC5997,RCC5998,RCC5999,RCC6000,RCC6001,RCC6002,RCC6003,RCC6004,RCC6005,RCC6006,RCC6007,RCC6008,RCC6009,RCC6010,RCC6079,RCC6080,RCC6081,RCC6082,RCC6083,RCC6084,RCC6085,RCC6087,RCC6088,RCC6094,RCC6096,RCC6100,RCC6101,RCC6102,RCC6103,RCC6104,RCC6105,RCC6106,RCC6107,RCC6108,RCC6109,RCC6110,RCC6111,RCC6112,RCC6113,RCC6115,RCC6116,RCC6117,RCC6118,RCC6119,RCC6120,RCC6121}, month = {dec}, pages = {2531}, keywords = {RCC1627, RCC1720, RCC3018, RCC3043, RCC3044, RCC3047, RCC3048, RCC3049, RCC3145, RCC3278, RCC3596, RCC4381, RCC4382, RCC4383, RCC4384, RCC4385, RCC4386, RCC4387, RCC4388, RCC4389, RCC4390, RCC4391, RCC4392, RCC4393, RCC4394, RCC4395, RCC4396, RCC4397, RCC4398, RCC4399, RCC4400, RCC4401, RCC4402, RCC4403, RCC4404, RCC4405, RCC4406, RCC4407, RCC4408, RCC4409, RCC4410, RCC4411, RCC4412, RCC4413, RCC4414, RCC4415, RCC4416, RCC4711, RCC4712, RCC4713, RCC4715, RCC4716, RCC4722, RCC4723, RCC4726, RCC4728, RCC4729, RCC4732, RCC4733, RCC4734, RCC5984, RCC5985, RCC5986, RCC5987, RCC5988, RCC5989, RCC5990, RCC5991, RCC5992, RCC5993, RCC5994, RCC5995, RCC5997, RCC5998, RCC5999, RCC6000, RCC6001, RCC6002, RCC6003, RCC6004, RCC6005, RCC6006, RCC6007, RCC6008, RCC6009, RCC6010, RCC6079, RCC6080, RCC6081, RCC6082, RCC6083, RCC6084, RCC6085, RCC6087, RCC6088, RCC6094, RCC6096, RCC6100, RCC6101, RCC6102, RCC6103, RCC6104, RCC6105, RCC6106, RCC6107, RCC6108, RCC6109, RCC6110, RCC6111, RCC6112, RCC6113, RCC6115, RCC6116, RCC6117, RCC6118, RCC6119, RCC6120, RCC6121}, issn = {2045-2322}, doi = {10.1038/s41598-020-59524-z}, url = {http://dx.doi.org/10.1038/s41598-020-59524-z http://www.nature.com/articles/s41598-020-59524-z}, author = {Cai, Ruibo and Kayal, Ehsan and Alves-de-Souza, Catharina and Bigeard, Estelle and Corre, Erwan and Jeanthon, Christian and Marie, Dominique and Porcel, Betina M and Siano, Raffaele and Szymczak, Jeremy and Wolf, Matthias and Guillou, Laure} } @article {Ribeiro2020, title = {Culturable diversity of Arctic phytoplankton during pack ice melting}, journal = {Elementa: Science of the Anthropocene}, volume = {8}, number = {1}, year = {2020}, note = {tex.mendeley-tags: RCC5197,RCC5198,RCC5199,RCC5200,RCC5201,RCC5202,RCC5203,RCC5204,RCC5205,RCC5206,RCC5207,RCC5208,RCC5209,RCC5210,RCC5211,RCC5212,RCC5213,RCC5214,RCC5215,RCC5216,RCC5217,RCC5218,RCC5219,RCC5220,RCC5221,RCC5222,RCC5223,RCC5224,RCC5225,RCC5226,RCC5227,RCC5228,RCC5229,RCC5230,RCC5231,RCC5232,RCC5233,RCC5234,RCC5235,RCC5236,RCC5237,RCC5238,RCC5239,RCC5240,RCC5241,RCC5242,RCC5243,RCC5244,RCC5245,RCC5246,RCC5247,RCC5248,RCC5249,RCC5250,RCC5251,RCC5252,RCC5253,RCC5254,RCC5255,RCC5256,RCC5257,RCC5258,RCC5259,RCC5260,RCC5261,RCC5262,RCC5263,RCC5264,RCC5265,RCC5266,RCC5267,RCC5268,RCC5269,RCC5270,RCC5271,RCC5272,RCC5273,RCC5274,RCC5275,RCC5276,RCC5277,RCC5278,RCC5279,RCC5280,RCC5281,RCC5282,RCC5283,RCC5284,RCC5285,RCC5286,RCC5287,RCC5288,RCC5289,RCC5290,RCC5291,RCC5292,RCC5293,RCC5294,RCC5295,RCC5296,RCC5297,RCC5298,RCC5299,RCC5300,RCC5301,RCC5302,RCC5303,RCC5304,RCC5305,RCC5306,RCC5307,RCC5308,RCC5309,RCC5310,RCC5311,RCC5312,RCC5313,RCC5314,RCC5315,RCC5316,RCC5317,RCC5318,RCC5319,RCC5320,RCC5321,RCC5322,RCC5323,RCC5324,RCC5325,RCC5326,RCC5327,RCC5328,RCC5329,RCC5330,RCC5331,RCC5332,RCC5333,RCC5334,RCC5335,RCC5336,RCC5337,RCC5338,RCC5339,RCC5340,RCC5341,RCC5342,RCC5343,RCC5344,RCC5345,RCC5346,RCC5347,RCC5348,RCC5349,RCC5350,RCC5351,RCC5352,RCC5353,RCC5354,RCC5355,RCC5356,RCC5357,RCC5358,RCC5359,RCC5360,RCC5361,RCC5362,RCC5363,RCC5364,RCC5365,RCC5366,RCC5367,RCC5368,RCC5369,RCC5370,RCC5371,RCC5372,RCC5373,RCC5374,RCC5375,RCC5376,RCC5377,RCC5378,RCC5379,RCC5380,RCC5381,RCC5382,RCC5383,RCC5384,RCC5385,RCC5386,RCC5387,RCC5388,RCC5389,RCC5390,RCC5391,RCC5392,RCC5393,RCC5394,RCC5395,RCC5396,RCC5397,RCC5398,RCC5399,RCC5400,RCC5401,RCC5402,RCC5403,RCC5404,RCC5405,RCC5406,RCC5407,RCC5408,RCC5409,RCC5410,RCC5411,RCC5412,RCC5413,RCC5414,RCC5415,RCC5416,RCC5417,RCC5418,RCC5419,RCC5420,RCC5421,RCC5422,RCC5423,RCC5424,RCC5425,RCC5426,RCC5427,RCC5428,RCC5429,RCC5430,RCC5431,RCC5432,RCC5433,RCC5434,RCC5435,RCC5436,RCC5437,RCC5438,RCC5439,RCC5440,RCC5441,RCC5442,RCC5443,RCC5444,RCC5445,RCC5446,RCC5447,RCC5448,RCC5449,RCC5450,RCC5451,RCC5452,RCC5453,RCC5454,RCC5455,RCC5456,RCC5457,RCC5458,RCC5459,RCC5460,RCC5461,RCC5462,RCC5463,RCC5464,RCC5465,RCC5466,RCC5467,RCC5468,RCC5469,RCC5470,RCC5471,RCC5472,RCC5473,RCC5474,RCC5475,RCC5476,RCC5477,RCC5478,RCC5479,RCC5480,RCC5481,RCC5482,RCC5483,RCC5484,RCC5485,RCC5486,RCC5487,RCC5488,RCC5489,RCC5490,RCC5491,RCC5492,RCC5493,RCC5494,RCC5495,RCC5496,RCC5497,RCC5498,RCC5499,RCC5500,RCC5501,RCC5502,RCC5503,RCC5504,RCC5505,RCC5506,RCC5507,RCC5508,RCC5509,RCC5510,RCC5511,RCC5512,RCC5513,RCC5514,RCC5515,RCC5516,RCC5517,RCC5518,RCC5519,RCC5520,RCC5521,RCC5522,RCC5523,RCC5524,RCC5525,RCC5526,RCC5527,RCC5528,RCC5529,RCC5530,RCC5531,RCC5532,RCC5533,RCC5534,RCC5535,RCC5536,RCC5537,RCC5538,RCC5539,RCC5540,RCC5541,RCC5542,RCC5543,RCC5544,RCC5545,RCC5546,RCC5547,RCC5548,RCC5549,RCC5550,RCC5551,RCC5552,RCC5553,RCC5554,RCC5555,RCC5556,RCC5557,RCC5558,RCC5559,RCC5560,RCC5561,RCC5562,RCC5563,RCC5564,RCC5565,RCC5566,RCC5567,RCC5568,RCC5569,RCC5570,RCC5571,RCC5572,RCC5573,RCC5574,RCC5575,RCC5576,RCC5577,RCC5578,RCC5579,RCC5580,RCC5581,RCC5582,RCC5583,RCC5584,RCC5585,RCC5586,RCC5587,RCC5588,RCC5589,RCC5590,RCC5591,RCC5592,RCC5593,RCC5594,RCC5595,RCC5596,RCC5597,RCC5598,RCC5599,RCC5600,RCC5601,RCC5602,RCC5603,RCC5604,RCC5605,RCC5606,RCC5607,RCC5608,RCC5609,RCC5610,RCC5611,RCC5612}, month = {feb}, pages = {6}, abstract = {Massive phytoplankton blooms develop at the Arctic ice edge, sometimes extending far under the pack ice. An extensive culturing effort was conducted before and during a phytoplankton bloom in Baffin Bay between April and July 2016. Different isolation strategies were applied, including flow cytometry cell sorting, manual single cell pipetting and serial dilution. Although all three techniques yielded the most common organisms, each technique retrieved specific taxa, highlighting the importance of using several methods to maximize the number and diversity of isolated strains. More than 1,000 cultures were obtained, characterized by 18S rRNA sequencing and optical microscopy and de-replicated to a subset of 276 strains presented in this work. Strains grouped into 57 genotypes defined by 100\% 18S rRNA sequence similarity. These genotypes spread across five divisions: Heterokontophyta, Chlorophyta, Cryptophyta, Haptophyta and Dinophyta. Diatoms were the most abundant group (193 strains), mostly represented by the genera Chaetoceros and Attheya. The genera Rhodomonas and Pyramimonas were the most abundant non-diatom nanoplankton strains, while Micromonas polaris dominated the picoplankton. Diversity at the class level was higher during the peak of the bloom. Potentially new species were isolated, in particular within the genera Navicula, Nitzschia, Coscinodiscus, Thalassiosira, Pyramimonas, Mantoniella and Isochrysis.}, keywords = {RCC5197, RCC5198, RCC5199, RCC5200, RCC5201, RCC5202, RCC5203, RCC5204, RCC5205, RCC5206, RCC5207, RCC5208, RCC5209, RCC5210, RCC5211, RCC5212, RCC5213, RCC5214, RCC5215, RCC5216, RCC5217, RCC5218, RCC5219, RCC5220, RCC5221, RCC5222, RCC5223, RCC5224, RCC5225, RCC5226, RCC5227, RCC5228, RCC5229, RCC5230, RCC5231, RCC5232, RCC5233, RCC5234, RCC5235, RCC5236, RCC5237, RCC5238, RCC5239, RCC5240, RCC5241, RCC5242, RCC5243, RCC5244, RCC5245, RCC5246, RCC5247, RCC5248, RCC5249, RCC5250, RCC5251, RCC5252, RCC5253, RCC5254, RCC5255, RCC5256, RCC5257, RCC5258, RCC5259, RCC5260, RCC5261, RCC5262, RCC5263, RCC5264, RCC5265, RCC5266, RCC5267, RCC5268, RCC5269, RCC5270, RCC5271, RCC5272, RCC5273, RCC5274, RCC5275, RCC5276, RCC5277, RCC5278, RCC5279, RCC5280, RCC5281, RCC5282, RCC5283, RCC5284, RCC5285, RCC5286, RCC5287, RCC5288, RCC5289, RCC5290, RCC5291, RCC5292, RCC5293, RCC5294, RCC5295, RCC5296, RCC5297, RCC5298, RCC5299, RCC5300, RCC5301, RCC5302, RCC5303, RCC5304, RCC5305, RCC5306, RCC5307, RCC5308, RCC5309, RCC5310, RCC5311, RCC5312, RCC5313, RCC5314, RCC5315, RCC5316, RCC5317, RCC5318, RCC5319, RCC5320, RCC5321, RCC5322, RCC5323, RCC5324, RCC5325, RCC5326, RCC5327, RCC5328, RCC5329, RCC5330, RCC5331, RCC5332, RCC5333, RCC5334, RCC5335, RCC5336, RCC5337, RCC5338, RCC5339, RCC5340, RCC5341, RCC5342, RCC5343, RCC5344, RCC5345, RCC5346, RCC5347, RCC5348, RCC5349, RCC5350, RCC5351, RCC5352, RCC5353, RCC5354, RCC5355, RCC5356, RCC5357, RCC5358, RCC5359, RCC5360, RCC5361, RCC5362, RCC5363, RCC5364, RCC5365, RCC5366, RCC5367, RCC5368, RCC5369, RCC5370, RCC5371, RCC5372, RCC5373, RCC5374, RCC5375, RCC5376, RCC5377, RCC5378, RCC5379, RCC5380, RCC5381, RCC5382, RCC5383, RCC5384, RCC5385, RCC5386, RCC5387, RCC5388, RCC5389, RCC5390, RCC5391, RCC5392, RCC5393, RCC5394, RCC5395, RCC5396, RCC5397, RCC5398, RCC5399, RCC5400, RCC5401, RCC5402, RCC5403, RCC5404, RCC5405, RCC5406, RCC5407, RCC5408, RCC5409, RCC5410, RCC5411, RCC5412, RCC5413, RCC5414, RCC5415, RCC5416, RCC5417, RCC5418, RCC5419, RCC5420, RCC5421, RCC5422, RCC5423, RCC5424, RCC5425, RCC5426, RCC5427, RCC5428, RCC5429, RCC5430, RCC5431, RCC5432, RCC5433, RCC5434, RCC5435, RCC5436, RCC5437, RCC5438, RCC5439, RCC5440, RCC5441, RCC5442, RCC5443, RCC5444, RCC5445, RCC5446, RCC5447, RCC5448, RCC5449, RCC5450, RCC5451, RCC5452, RCC5453, RCC5454, RCC5455, RCC5456, RCC5457, RCC5458, RCC5459, RCC5460, RCC5461, RCC5462, RCC5463, RCC5464, RCC5465, RCC5466, RCC5467, RCC5468, RCC5469, RCC5470, RCC5471, RCC5472, RCC5473, RCC5474, RCC5475, RCC5476, RCC5477, RCC5478, RCC5479, RCC5480, RCC5481, RCC5482, RCC5483, RCC5484, RCC5485, RCC5486, RCC5487, RCC5488, RCC5489, RCC5490, RCC5491, RCC5492, RCC5493, RCC5494, RCC5495, RCC5496, RCC5497, RCC5498, RCC5499, RCC5500, RCC5501, RCC5502, RCC5503, RCC5504, RCC5505, RCC5506, RCC5507, RCC5508, RCC5509, RCC5510, RCC5511, RCC5512, RCC5513, RCC5514, RCC5515, RCC5516, RCC5517, RCC5518, RCC5519, RCC5520, RCC5521, RCC5522, RCC5523, RCC5524, RCC5525, RCC5526, RCC5527, RCC5528, RCC5529, RCC5530, RCC5531, RCC5532, RCC5533, RCC5534, RCC5535, RCC5536, RCC5537, RCC5538, RCC5539, RCC5540, RCC5541, RCC5542, RCC5543, RCC5544, RCC5545, RCC5546, RCC5547, RCC5548, RCC5549, RCC5550, RCC5551, RCC5552, RCC5553, RCC5554, RCC5555, RCC5556, RCC5557, RCC5558, RCC5559, RCC5560, RCC5561, RCC5562, RCC5563, RCC5564, RCC5565, RCC5566, RCC5567, RCC5568, RCC5569, RCC5570, RCC5571, RCC5572, RCC5573, RCC5574, RCC5575, RCC5576, RCC5577, RCC5578, RCC5579, RCC5580, RCC5581, RCC5582, RCC5583, RCC5584, RCC5585, RCC5586, RCC5587, RCC5588, RCC5589, RCC5590, RCC5591, RCC5592, RCC5593, RCC5594, RCC5595, RCC5596, RCC5597, RCC5598, RCC5599, RCC5600, RCC5601, RCC5602, RCC5603, RCC5604, RCC5605, RCC5606, RCC5607, RCC5608, RCC5609, RCC5610, RCC5611, RCC5612}, issn = {2325-1026}, doi = {10.1525/elementa.401}, url = {https://www.biorxiv.org/content/10.1101/642264v1 https://www.elementascience.org/article/10.1525/elementa.401/}, author = {Ribeiro, Catherine G{\'e}rikas and dos Santos, Adriana Lopes and Gourvil, Priscillia and Le Gall, Florence and Marie, Dominique and Tragin, Margot and Probert, Ian and Vaulot, Daniel} } @article {Zimmerman2019, title = {Closely related viruses of the marine picoeukaryotic alga Ostreococcus lucimarinus exhibit different ecological strategies}, journal = {Environmental Microbiology}, volume = {00}, year = {2019}, note = {tex.mendeley-tags: RCC3401,RCC393,RCC829}, abstract = {SUMMARY In marine ecosystems viruses are major disrupters of the direct flow of carbon and nutrients to higher trophic levels. While the genetic diversity of several eukaryotic phytoplankton virus groups has been characterized, their infection dynamics are less understood, such that the physiological and ecological implications of their diversity remain unclear. We compared genomes and infection phenotypes of the two most closely related cultured phycodnaviruses infecting the widespread picoprasinophyte Ostreococcus lucimarinus under standard- (1.3 divisions d-1) and limited-light (0.41 divisions d-1) nutrient replete conditions. OlV7 infection caused early arrest of the host cell cycle, coinciding with a significantly higher proportion of infected cells than OlV1-amended treatments, regardless of host growth rate. OlV7 treatments showed a near-50-fold increase of progeny virions at the higher host growth rate, contrasting with OlV1{\textquoteright}s 16-fold increase. However, production of OlV7 virions was more sensitive than OlV1 production to reduced host growth rate, suggesting fitness trade-offs between infection efficiency and resilience to host physiology. Moreover, while organic matter released from OlV1- and OlV7-infected hosts had broadly similar chemical composition, some distinct molecular signatures were observed. Collectively, these results suggest that current views on viral relatedness through marker and core gene analyses underplay operational divergence and consequences for host ecology. This article is protected by copyright. All rights reserved.}, keywords = {rcc3401, RCC393, RCC829}, issn = {14622920}, doi = {10.1111/1462-2920.14608}, author = {Zimmerman, Amy E. and Bachy, Charles and Ma, Xiufeng and Roux, Simon and Jang, Ho Bin and Sullivan, Matthew B. and Waldbauer, Jacob R. and Worden, Alexandra Z.} } @mastersthesis {VanTol2019, title = {Computational and experimental models of diatom-bacteria interaction}, year = {2019}, note = {ISBN: 9781085779104 Pages: 161 Publication title: ProQuest dissertations and theses tex.mendeley-tags: RCC80}, type = {phd}, abstract = {Microbial interactions structure ecosystems and fuel biogeochemical cycling. The metabolic activities operating in the ocean are critical to the entire planet. In this work, I focused on interactions between diatoms and heterotrophic bacteria. Diatoms are a group of unicellular brown algae with frustules composed of silica. They form the base of coastal and polar marine food webs and contribute one fifth of global primary productivity. The inorganic nutrients fixed by oxygenic photosynthesis fuel secondary productivity by marine bacteria. Marine bacteria and diatoms have a range of different interaction strategies; many are still being elucidated.In Chapter 1, I studied the antagonistic effects of a flavobacterium on diatom cell division. Croceibacter atlanticus inhibits cytokinesis in many species, causing the cells to elongate, become mutlinucleated, and filled with plastids.In Chapter 2, I created a metabolic model of the diatom Thalassiosira pseudonana using the genome and physiological data from the literature. Simulations of diatom growth using Flux Balance Analysis revealed a role for nitrate and sulfate assimilation in dissipating reductants from the plastid. Changing redox and nutrient conditions causes the cell to secrete metabolites including organic carbon, nitrogen, and sulfur.In Chapter 3, I created a metabolic model of the B12-producing alphaproteobacterium Ruegeria pomeroyi. Previous work has demonstrated that R. pomeroyi will provide cobalamin to T. pseudonana in B12-starvation conditions in exchange for organic sulfur and nitrogen. I constrained the metabolic models with transcriptomic data of T. pseudonana and R. pomeroyi in co-culture and simulated their interaction.The distinct character of metabolites produced by diatoms likely fuels interactions with bacteria capable of utilizing those molecules. Bacteria influence diatom metabolism by interfering with the cell cycle, through nutrient-limitation, by altering redox conditions, and providing the cofactors required for growth. In this work, I have contributed to the literature exploring the complexity of diatom-bacteria interactions, where chemical or peptide cues, signals, and antagonists underlie the dynamics of microbial interactions. I have also created a framework for exploring more general metabolic exchanges between diatoms and bacteria. Genome-scale metabolic modeling of interactions between distinct marine microbial communities may be key to accurately predicting the character of dissolve organic matter in the ocean.}, keywords = {Croceibacter atlanticus, diatoms, Genome-scale met, RCC80}, url = {https://remotexs.ntu.edu.sg/user/login?url=https://search.proquest.com/docview/2305846221?accountid=12665}, author = {van Tol, Helena M} } @article {Fox2018, title = {Calcein staining as a tool to investigate coccolithophore calcification}, journal = {Frontiers in Marine Science}, volume = {5}, number = {September}, year = {2018}, note = {tex.mendeley-tags: RCC 1461,RCC 3777,RCC1130,RCC1303,RCC1456}, abstract = {This brief paper summarizes the literature on academic accommodations for students with psychiatric disabilities. A definition of psychiatric disability precedes a brief summary of the following specific psychiatric diagnoses: depression, bipolar affective disorder; borderline personality disorder; schizophrenia; and anxiety disorders. Also noted are behavior or personality disorders specifically excluded from coverage under the Americans with Disabilities Act. Functional limitations of this population that may affect academic performance are then listed and defined. Among these are medication side effects, sustaining concentration, maintaining stamina, interacting with others, responding to negative feedback, responding to change, and severe test anxiety. Examples of appropriate instructional strategies are followed by a discussion of reasonable accommodations to provide these students with equal access to the curriculum. Examples are then given of classroom accommodations, examination accommodations, and assignment accommodations. Characteristics of accommodations that are not reasonable are also listed. The paper concludes with a resource list including Web site and contact information for the DO-IT (Disabilities, Opportunities, Internetworking, and Technology) Project. (DB)}, keywords = {bet hedging, calcein, Calcification, coccolith, coccolithophore, flow cytometry, haptophyte, RCC1130, RCC1303, RCC1456, RCC1461, RCC3777, secretion}, issn = {2296-7745}, doi = {10.3389/fmars.2018.00326}, url = {https://www.frontiersin.org/article/10.3389/fmars.2018.00326/full}, author = {Fox, Emily and Meyer, Erin and Panasiak, Natalie and Taylor, Alison R.} } @article {McQuaid2018, title = {Carbonate-sensitive phytotransferrin controls high-affinity iron uptake in diatoms}, journal = {Nature}, volume = {555}, number = {7697}, year = {2018}, note = {Publisher: Nature Publishing Group tex.mendeley-tags: RCC2967}, month = {mar}, pages = {534{\textendash}537}, abstract = {Iron is an essential nutrient for photosynthetic plankton (phytoplankton), but owing to its low solubility in vast areas of the ocean the concentration of this metal is low, limiting the growth of the phytoplankton. Andrew Allen and co-workers show that the phytoplankton Phaeodactylum tricornutum has developed a specific iron acquisition mechanism that relies on activity of the ISIP2A protein. ISIP2A represents a functional analogue of transferrin{\textemdash}a metazoan protein that binds iron with high affinity{\textemdash}as both proteins use similar iron binding, internalization and release mechanisms, suggesting their independent and convergent evolution. Both proteins bind iron through a synergistic interaction of ferric iron and CO32-, and because ocean acidification decreases CO32- concentration it may also decrease phytoplankton iron uptake and growth.}, keywords = {RCC2967}, issn = {0028-0836}, doi = {10.1038/nature25982}, url = {http://dx.doi.org/10.1038/nature25982 http://www.nature.com/doifinder/10.1038/nature25982}, author = {McQuaid, Jeffrey B. and Kustka, Adam B. and Obornik, Miroslav and Horak, Ales and McCrow, John P. and Karas, Bogumil J. and Zheng, Hong and Kindeberg, Theodor and Andersson, Andreas J. and Barbeau, Katherine A. and Allen, Andrew E.} } @article {Paerl2018, title = {Carboxythiazole is a key microbial nutrient currency and critical component of thiamin biosynthesis}, journal = {Scientific Reports}, volume = {8}, number = {1}, year = {2018}, note = {Publisher: Springer US tex.mendeley-tags: RCC4222,RCC745}, pages = {5940}, keywords = {RCC4222, RCC745}, issn = {2045-2322}, doi = {10.1038/s41598-018-24321-2}, url = {http://www.nature.com/articles/s41598-018-24321-2}, author = {Paerl, Ryan W. and Bertrand, Erin M. and Rowland, Elden and Schatt, Phillippe and Mehiri, Mohamed and Niehaus, Thomas D. and Hanson, Andrew D. and Riemann, Lasse and Yves-Bouget, Francois} } @article {Guyon2018, title = {Comparative analysis of culture conditions for the optimization of carotenoid production in several strains of the picoeukaryote ostreococcus}, journal = {Marine Drugs}, volume = {16}, number = {3}, year = {2018}, note = {tex.mendeley-tags: 2018,RCC745,RCC802,RCC809,rcc}, pages = {76}, abstract = {Microalgae are promising sources for the sustainable production of compounds of interest for biotechnologies. Compared to higher plants, microalgae have a faster growth rate and can be grown in industrial photobioreactors. The microalgae biomass contains specific metabolites of high added value for biotechnology such as lipids, polysaccharides or carotenoid pigments. Studying carotenogenesis is important for deciphering the mechanisms of adaptation to stress tolerance as well as for biotechnological production. In recent years, the picoeukaryote Ostreococcus tauri has emerged as a model organism thanks to the development of powerful genetic tools. Several strains of Ostreococcus isolated from different environments have been characterized with respect to light response or iron requirement. We have compared the carotenoid contents and growth rates of strains of Ostreococcus (OTTH595, RCC802 and RCC809) under a wide range of light, salinity and temperature conditions. Carotenoid profiles and productivities varied in a strain-specific and stress-dependent manner. Our results also illustrate that phylogenetically related microalgal strains originating from different ecological niches present specific interests for the production of specific molecules under controlled culture conditions.}, keywords = {2018, carotenoids, GROWTH RATE, Light, Ostreococcus, rcc, RCC745, RCC802, RCC809, salinity, temperature}, issn = {1660-3397}, doi = {10.3390/md16030076}, url = {http://www.mdpi.com/1660-3397/16/3/76}, author = {Guyon, Jean-baptiste and Schatt, Philippe and Lozano, Jean-Claude and Liennard, Marion and Bouget, Fran{\c c}ois-Yves} } @article {Farhat2018, title = {Comparative time-scale gene expression analysis highlights the infection processes of two amoebophrya strains}, journal = {Frontiers in Microbiology}, volume = {9}, number = {October}, year = {2018}, note = {tex.mendeley-tags: RCC1627,RCC3596,RCC4383,RCC4398}, month = {oct}, pages = {1{\textendash}19}, keywords = {amoebophrya, Dinoflagellates, Gene Expression, infection, oxidative stress response, parasite, plankton, RCC1627, RCC3596, RCC4383, RCC4398, syndiniales}, issn = {1664-302X}, doi = {10.3389/fmicb.2018.02251}, url = {https://www.frontiersin.org/article/10.3389/fmicb.2018.02251/full}, author = {Farhat, Sarah and Florent, Isabelle and Noel, Benjamin and Kayal, Ehsan and Da Silva, Corinne and Bigeard, Estelle and Alberti, Adriana and Labadie, Karine and Corre, Erwan and Aury, Jean-Marc and Rombauts, Stephane and Wincker, Patrick and Guillou, Laure and Porcel, Betina M.} } @article {Kenworthy2018, title = {Compared stress tolerance to short-term exposure in native and invasive tunicates from the NE Atlantic: when the invader performs better}, journal = {Marine Biology}, volume = {165}, number = {10}, year = {2018}, note = {tex.mendeley-tags: RCC179}, pages = {164}, abstract = {{The combined impact of invasive species and climate change threatens natural systems worldwide, often facilitating the expansion of harmful invasive species. It is imperative to understand the mechanisms behind why species become invasive and widespread. Traditionally, it is thought that invasive species have greater tolerances to a wider array of environmental conditions than natives. We, therefore, tested the hypothesis that invasive species are more tolerant to the effects of short-term exposure to temperature and salinity stress. Using unifactorial experiments, we compared the tolerances of two common fouling NE Atlantic ascidians, the native Ciona intestinalis and the invasive Styela clava, to increased temperature and decreased salinity. We measured lethal and behavioural responses affecting 50\% of populations to give an indication of the tolerance limits for temperature (LT50) and salinity (EC50), and respiration rate to give an indication of the change in metabolic response. The invasive S. clava was more tolerant to increased stress (LT50 = 29.5 {\textdegree}C}, keywords = {RCC179}, issn = {1432-1793}, doi = {10.1007/s00227-018-3420-1}, url = {https://doi.org/10.1007/s00227-018-3420-1}, author = {Kenworthy, Joseph M and Davoult, Dominique and Lejeusne, 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 {Gnouma2017, title = {Changes in fatty acids profile, monosaccharide profile and protein content during batch growth of Isochrysis galbana (T.iso)}, journal = {Aquaculture Research}, volume = {48}, number = {9}, year = {2017}, note = {Publisher: John Wiley \& Sons, Ltd (10.1111) tex.mendeley-tags: RCC1349}, month = {sep}, pages = {4982{\textendash}4990}, abstract = {Abstract To investigate the nutritional value of the marine micro-alga Isochrysis galbana Tahitian Isochrysis strain (T.iso) as an alternative feed for aquaculture during culture age, its biochemical composition was studied under autotrophic and controlled culture conditions at different growth stages: exponential phase, early and late stationary phases and decay phase. Analysis showed that C14:0, C16:0, C16:1, C18:4 (n-3) and C22:6 (n-3) were the most abundant fatty acids in this alga at different growth stages. The highest values of monounsaturated fatty acids were recorded at the late stationary and the decay phases. However, the highest levels of polyunsaturated fatty acids were observed at the early stationary phase. At all growth stages, I. galbana (T.iso) contained arabinose, xylose, mannose, galactose and glucose. Glucose represented the main sugar, and its content per dry alga biomass weight increased with increasing age of the culture and reached about fourfold in the decay phase. The maximum protein content was also observed during this last phase.}, keywords = {fatty acids, growth phases, Isochrysis galbana (T.iso), monosaccharides, proteins, RCC1349}, issn = {1355-557X}, doi = {10.1111/are.13316}, url = {https://doi.org/10.1111/are.13316}, author = {Gnouma, Asma and Sadovskaya, Irina and Souissi, Anissa and Sebai, Khaled and Medhioub, Amel and Grard, Thierry and Souissi, Sami} } @article {Dorrell2017, title = {Chimeric origins of ochrophytes and haptophytes revealed through an ancient plastid proteome}, journal = {eLife}, volume = {6}, year = {2017}, month = {may}, pages = {1{\textendash}45}, abstract = {Plastids are supported by a wide range of proteins encoded within the nucleus and imported from the cytoplasm. These plastid-targeted proteins may originate from the endosymbiont, the host, or other sources entirely. Here, we identify and characterise 770 plastid-targeted proteins that are conserved across the ochrophytes, a major group of algae including diatoms, pelagophytes and kelps, that possess plastids derived from red algae. We show that the ancestral ochrophyte plastid proteome was an evolutionary chimera, with 25\% of its phylogenetically tractable nucleus-encoded proteins deriving from green algae. We additionally show that functional mixing of host and plastid proteomes, such as through dual-targeting, is an ancestral feature of plastid evolution. Finally, we detect a clear phylogenetic signal from one ochrophyte subgroup, the lineage containing pelagophytes and dictyochophytes, in plastid-targeted proteins from another major algal lineage, the haptophytes. This may represent a possible serial endosymbiosis event deep in eukaryotic evolutionary history.}, keywords = {2017, RCC1486, RCC1523, RCC1537, RCC1587, SBR$_\textrmP$hyto$_\textrmE$PPO}, issn = {2050-084X}, doi = {10.7554/eLife.23717}, url = {http://elifesciences.org/lookup/doi/10.7554/eLife.23717}, author = {Dorrell, Richard G and Gile, Gillian and McCallum, Giselle and M{\'e}heust, Rapha{\"e}l and Bapteste, Eric P and Klinger, Christen M and Brillet-Gu{\'e}guen, Loraine and Freeman, Katalina D and Richter, Daniel J and Bowler, Chris} } @article {LopesdosSantos2017, title = {Chloropicophyceae, a new class of picophytoplanktonic prasinophytes}, journal = {Scientific Reports}, volume = {7}, number = {1}, year = {2017}, note = {tex.mendeley-tags: 2017,RCC1019,RCC1021,RCC1032,RCC1043,RCC1124,RCC138,RCC15,RCC1871,RCC19,RCC227,RCC2335,RCC2337,RCC2339,RCC287,RCC297,RCC3368,RCC3373,RCC3374,RCC3375,RCC3376,RCC3402,RCC4429,RCC4430,RCC4434,RCC4572,RCC4656,RCC696,RCC700,RCC701,RCC712,RCC713,RCC717,RCC719,RCC722,RCC726,RCC856,RCC857,RCC887,RCC917,RCC996,RCC997,RCC998,RCC999,sbr?hyto$_\textrmd$ipo}, month = {dec}, pages = {14019}, keywords = {2017, RCC1019, RCC1021, RCC1032, RCC1043, RCC1124, RCC138, RCC15, RCC1871, RCC19, RCC227, RCC2335, RCC2337, RCC2339, RCC287, RCC297, RCC3368, RCC3373, RCC3374, RCC3375, RCC3376, RCC3402, RCC4429, RCC4430, RCC4434, RCC4572, RCC4656, RCC696, RCC700, RCC701, RCC712, RCC713, RCC717, RCC719, RCC722, RCC726, RCC856, RCC857, RCC887, RCC917, RCC996, RCC997, RCC998, RCC999, sbr?hyto$_\textrmd$ipo}, issn = {2045-2322}, doi = {10.1038/s41598-017-12412-5}, url = {http://www.nature.com/articles/s41598-017-12412-5}, author = {Lopes dos Santos, Adriana and Pollina, Thibaut and Gourvil, Priscillia and Corre, Erwan and Marie, Dominique and Garrido, Jos{\'e} Luis and Rodr{\'\i}guez, Francisco and No{\"e}l, Mary-H{\'e}l{\`e}ne and Vaulot, Daniel and Eikrem, Wenche} } @article {Satjarak2017, title = {Comparative DNA sequence analyses of Pyramimonas parkeae (Prasinophyceae) chloroplast genomes}, journal = {Journal of Phycology}, volume = {53}, number = {2}, year = {2017}, note = {tex.mendeley-tags: RCC1987,RCC2009,RCC2015,RCC2500,RCC2501,RCC2502,RCC619}, month = {apr}, pages = {415{\textendash}424}, keywords = {RCC1987, RCC2009, RCC2015, RCC2500, RCC2501, RCC2502, RCC619}, issn = {00223646}, doi = {10.1111/jpy.12515}, url = {http://doi.wiley.com/10.1111/jpy.12515}, author = {Satjarak, Anchittha and Graham, Linda E.}, editor = {Wood, M.} } @article {Stuart2016, title = {Copper toxicity response influences mesotrophic S ynechococcus community structure}, journal = {Environmental Microbiology}, volume = {19}, number = {2}, year = {2017}, note = {ISBN: 3907122046 tex.mendeley-tags: 2016,RCC1086,RCC2673}, month = {feb}, pages = {756{\textendash}769}, abstract = {Picocyanobacteria from the genus Synechococcus are ubiquitous in ocean waters. Their phylogenetic and genomic diversity suggests ecological niche differentiation, but the selective forces influencing this are not well defined. Marine picocyanobacteria are sensitive to Cu toxicity, so adaptations to this stress could represent a selective force within, and between, {\textquotedblleft}species{\textquotedblright} also known as clades. We compared Cu stress responses in cultures and natural populations of marine Synechococcus from two co-occurring major mesotrophic clades (I and IV). Using custom microarrays and proteomics to characterize expression responses to Cu in the lab and field, we found evidence for a general stress regulon in marine Synechococcus. However, the two clades also exhibited distinct responses to copper. The Clade I representative induced expression of genomic island genes in cultures and Southern California Bight populations, while the Clade IV representative downregulated Fe-limitation proteins. Copper incubation experiments suggest that Clade IV populations may harbor stress-tolerant subgroups, and thus fitness tradeoffs may govern Cu-tolerant strain distributions. This work demonstrates that Synechococcus has distinct adaptive strategies to deal with Cu toxicity at both the clade and subclade level, implying that metal toxicity and stress response adaptations represent an important selective force for influencing diversity within marine Synechococcus populations. This}, keywords = {2016, alkylsuccinate, methanogenic, n -alkane, paraffin, RCC1086, RCC2673, smithella, syntrophy}, issn = {14622912}, doi = {10.1111/1462-2920.13630}, url = {http://doi.wiley.com/10.1111/1462-2920.13630}, author = {Stuart, Rhona K. and Bundy, Randelle and Buck, Kristen and Ghassemain, Majid and Barbeau, Kathy and Palenik, Brian} } @article {Leliaert2016, title = {Chloroplast phylogenomic analyses reveal the deepest-branching lineage of the Chlorophyta, Palmophyllophyceae class. nov.}, journal = {Scientific Reports}, volume = {6}, year = {2016}, note = {tex.mendeley-tags: 2016,RCC15,RCC299}, month = {may}, pages = {25367}, keywords = {2016, RCC15, RCC299}, issn = {2045-2322}, doi = {10.1038/srep25367}, url = {http://www.nature.com/articles/srep25367}, author = {Leliaert, Frederik and Tronholm, Ana and Lemieux, Claude and Turmel, Monique and DePriest, Michael S. and Bhattacharya, Debashish and Karol, Kenneth G. and Fredericq, Suzanne and Zechman, Frederick W. and Lopez-Bautista, Juan M.} } @article {Coutinho2015, title = {Comparative genomics of Synechococcus and proposal of the new genus Parasynechococcus}, journal = {PeerJ}, year = {2015}, note = {tex.mendeley-tags: rcc}, pages = {e{\textendash}1522}, keywords = {rcc}, issn = {2167-8359}, doi = {10.7717/peerj.1522}, author = {Coutinho, Felipe and Tschoeke, Diogo Antonio and Thompson, Fabiano and Thomson, Cristiane} } @article {Bombar2014, title = {Comparative genomics reveals surprising divergence of two closely related strains of uncultivated UCYN-A cyanobacteria}, journal = {The ISME Journal}, volume = {8}, number = {12}, year = {2014}, note = {Publisher: Nature Publishing Group tex.mendeley-tags: rcc}, pages = {2530{\textendash}2542}, keywords = {rcc}, issn = {1751-7362}, doi = {10.1038/ismej.2014.167}, url = {http://www.nature.com/doifinder/10.1038/ismej.2014.167}, author = {Bombar, Deniz and Heller, Philip and Sanchez-Baracaldo, Patricia and Carter, Brandon J and Zehr, Jonathan P} } @article {Pittera2014, title = {Connecting thermal physiology and latitudinal niche partitioning in marine Synechococcus}, journal = {The ISME journal}, volume = {8}, number = {6}, year = {2014}, note = {Publisher: International Society for Microbial Ecology tex.mendeley-tags: 2014,macumba,microb3,rcc,sbr?hyto?app}, pages = {1221{\textendash}1236}, 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 [beta]-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[thinsp][deg]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.}, keywords = {2014, adaptation, ecotype, MACUMBA, marine cyanobacteria, MicroB3, rcc, SBR$_\textrmP$hyto$_\textrmP$PM, sbr?hyto?app, Synechococcus, temperature}, doi = {10.1038/ismej.2013.228}, url = {http://dx.doi.org/10.1038/ismej.2013.228 10.1038/ismej.2013.228}, author = {Pittera, Justine and Humily, Florian and Thorel, Maxine and Grulois, Daphne and Garczarek, Laurence and Six, Christophe} } @article {Bellec2014, title = {Cophylogenetic interactions between marine viruses and eukaryotic picophytoplankton}, journal = {BMC Evolutionary Biology}, volume = {14}, number = {1}, year = {2014}, note = {tex.mendeley-tags: RCC1105,RCC1107,RCC1108,RCC1109,RCC114,RCC2482,RCC2483,RCC2484,RCC2485,RCC344,RCC356,RCC373,RCC418,RCC461,RCC464,RCC465,RCC629,RCC658,RCC745,RCC789,RCC834}, pages = {59}, abstract = {BACKGROUND:Numerous studies have investigated cospeciation (or cophylogeny) in various host-symbiont systems, and different patterns were inferred, from strict cospeciation where symbiont phylogeny mirrors host phylogeny, to complete absence of correspondence between trees. The degree of cospeciation is generally linked to the level of host specificity in the symbiont species and the opportunity they have to switch hosts. In this study, we investigated cophylogeny for the first time in a microalgae-virus association in the open sea, where symbionts are believed to be highly host-specific but have wide opportunities to switch hosts. We studied prasinovirus-Mamiellales associations using 51 different viral strains infecting 22 host strains, selected from the characterisation and experimental testing of the specificities of 313 virus strains on 26 host strains.RESULTS:All virus strains were restricted to their host genus, and most were species-specific, but some of them were able to infect different host species within a genus. Phylogenetic trees were reconstructed for viruses and their hosts, and their congruence was assessed based on these trees and the specificity data using different cophylogenetic methods, a topology-based approach, Jane, and a global congruence method, ParaFit. We found significant congruence between virus and host trees, but with a putatively complex evolutionary history.CONCLUSIONS:Mechanisms other than true cospeciation, such as host-switching, might explain a part of the data. It has been observed in a previous study on the same taxa that the genomic divergence between host pairs is larger than between their viruses. It implies that if cospeciation predominates in this algae-virus system, this would support the hypothesis that prasinoviruses evolve more slowly than their microalgal hosts, whereas host switching would imply that these viruses speciated more recently than the divergence of their host genera.}, keywords = {rcc, RCC1105, rcc1107, RCC1108, RCC1109, RCC114, RCC2482, RCC2483, RCC2484, RCC2485, RCC344, RCC356, RCC373, RCC418, RCC461, RCC464, RCC465, RCC629, RCC658, RCC745, RCC789, RCC834, SBR$_\textrmP$hyto$_\textrmD$PO}, doi = {10.1186/1471-2148-14-59}, url = {http://www.biomedcentral.com/1471-2148/14/59}, author = {Bellec, Laure and Clerissi, Camille and Edern, Roseline and Foulon, Elodie and Simon, Nathalie and Grimsley, Nigel and Desdevises, Yves} } @article {Rousseau2013, title = {Characterization of {\textexclamdown}i{\textquestiondown}Phaeocystis globosa{\textexclamdown}/i{\textquestiondown} (haptophyceae), the blooming species in the southern north sea}, journal = {Journal of Sea Research}, volume = {76}, year = {2013}, note = {tex.mendeley-tags: 2013,rcc,sbr?hyto$_\textrmd$ipo}, pages = {105{\textendash}113}, keywords = {2013, ASSEMBLE, rcc, SBR$_\textrmP$hyto$_\textrmD$PO, sbr?hyto$_\textrmd$ipo, Souchotheque}, doi = {10.1016/j.seares.2012.07.011}, author = {Rousseau, V and Lantoine, F and Rodriguez, F and Le Gall, F and Chr{\'e}tiennot-Dinet, M.-J. and Lancelot, C} } @article {Drescher2012, title = {Coccolithogenesis in scyphosphaera apsteinii (prymnesiophyceae)}, journal = {Journal of Phycology}, volume = {48}, number = {6}, year = {2012}, note = {tex.mendeley-tags: RCC1456}, pages = {1343{\textendash}1361}, abstract = {Coccolithophores are the most significant producers of marine biogenic calcite, although the intracellular calcification process is poorly understood. In the case of Scyphosphaera apsteinii Lohmann 1902, flat ovoid muroliths and bulky, vase-shaped lopadoliths with a range of intermediate morphologies may be produced by a single cell. This polymorphic species is within the Zygodiscales, a group that remains understudied with respect to ultrastructure and coccolith ontogeny. We therefore undertook an analysis of cell ultrastructure, morphology, and coccolithogenesis. The cell ultrastructure showed many typical haptophyte features, with calcification following a similar pattern to that described for other heterococcolith bearing species including Emiliania huxleyi. Of particular significance was the reticular body role in governing fine-scale morphology, specifically the central pore formation of the coccolith. Our observations also highlighted the essential role of the inter- and intracrystalline organic matrix in growth and arrangement of the coccolith calcite. S. apsteinii secreted mature coccoliths that attached to the plasma membrane via fibrillar material. Time-lapse light microscopy demonstrated secretion of lopadoliths occurred base first before being actively repositioned at the cell surface. Significantly, growth irradiance influenced the coccosphere composition with fewer lopadoliths being formed relative to muroliths at higher light intensities. Overall, our observations support dynamic metabolic (i.e., in response to growth irradiance), sensory and cytoskeletal control over the morphology and secretion of polymorphic heterococcoliths. With a basic understanding of calcification established, S. apsteinii could be a valuable model to further study coccolithophore calcification and cell physiological responses to ocean acidification.}, keywords = {Calcification, coccolithogenesis, coccolithophore, organic matrix, rcc, RCC1456, reticular body, secretion, ultrastructure, Zygodiscales}, doi = {10.1111/j.1529-8817.2012.01227.x}, url = {http://dx.doi.org/10.1111/j.1529-8817.2012.01227.x}, author = {Drescher, Brandon and Dillaman, Richard M and Taylor, Alison R} } @article {Balzano2012, title = {Composition of the summer photosynthetic pico and nanoplankton communities in the Beaufort Sea assessed by T-RFLP and sequences of the 18S rRNA gene from flow cytometry sorted samples}, journal = {The ISME journal}, volume = {6}, number = {8}, year = {2012}, note = {ISBN: 1751-7362 tex.mendeley-tags: 2012,rcc,sbr?hyto$_\textrmd$ipo}, pages = {1480{\textendash}1498}, abstract = {The composition of photosynthetic pico and nanoeukaryotes was investigated in the North East Pacific and the Arctic Ocean with special emphasis on the Beaufort Sea during the MALINA cruise in summer 2009. Photosynthetic populations were sorted using flow cytometry based on their size and pigment fluorescence. Diversity of the sorted photosynthetic eukaryotes was determined using terminal-restriction fragment length polymorphism analysis and cloning/sequencing of the 18S ribosomal RNA gene. Picoplankton was dominated by Mamiellophyceae, a class of small green algae previously included in the prasinophytes: in the North East Pacific, the contribution of an Arctic Micromonas ecotype increased steadily northward becoming the only taxon occurring at most stations throughout the Beaufort Sea. In contrast, nanoplankton was more diverse: North Pacific stations were dominated by Pseudo-nitzschia sp. whereas those in the Beaufort Sea were dominated by two distinct Chaetoceros species as well as by Chrysophyceae, Pelagophyceae and Chrysochromulina spp.. This study confirms the importance of Arctic Micromonas within picoplankton throughout the Beaufort Sea and demonstrates that the photosynthetic picoeukaryote community in the Arctic is much less diverse than at lower latitudes. Moreover, in contrast to what occurs in warmer waters, most of the key pico- and nanoplankton species found in the Beaufort Sea could be successfully established in culture.}, keywords = {2012, ASSEMBLE, Chaetoceros, MALINA, Pyramimonas, rcc, SBR$_\textrmP$hyto$_\textrmD$PO, sbr?hyto$_\textrmd$ipo, Souchotheque}, issn = {1751-7362}, doi = {10.1038/ismej.2011.213}, author = {Balzano, Sergio and Marie, Dominique and Gourvil, Priscillia and Vaulot, Daniel} } @article {Guillou2011, title = {Characterization of the Parmales: much more than the resolution of a taxonomic enigma}, journal = {Journal of Phycology}, volume = {47}, year = {2011}, note = {tex.mendeley-tags: 2011,rcc,sbr?hyto$_\textrmd$ipo}, pages = {2{\textendash}4}, keywords = {2011, rcc, SBR$_\textrmP$hyto, sbr?hyto$_\textrmd$ipo}, doi = {10.1111/j.1529-8817.2010.00951.x}, author = {Guillou, L} } @article {Langer2011a, title = {CO2 mediation of adverse effects of seawater acidification in Calcidiscus leptoporus}, journal = {Geochemistry Geophysics Geosystems}, volume = {12}, number = {5}, year = {2011}, note = {ISBN: 1525-2027 tex.mendeley-tags: 2011,RCC1135,rcc}, pages = {1{\textendash}8}, abstract = {The coccolithophore Calcidiscus leptoporus (strain RCC1135) was grown in dilute batch culture at CO2 levels ranging from \~200 to \~1600 matm. Increasing CO2 concentration led to an increased percentage of malformed coccoliths and eventually (at \~1500 matm CO2) to aggregation of cells. Carbonate chemistry of natural seawater was manipulated in three ways: first, addition of acid; second, addition of a HCO3 -/CO3 2- solution; and third, addition of both acid and HCO3 -/CO32- solution. The data set allowed the disentangling of putative effects of the different parameters of the carbonate system. It is concluded that CO2 is the parameter of the carbonate system which causes both aberrant coccolithogenesis and aggregation of cells.}, keywords = {2011, Calcification, coccolithophores, morphology, ocean acidification., rcc, RCC1135}, issn = {1525-2027}, doi = {10.1029/2010GC003393}, url = {http://www.agu.org/pubs/crossref/2011/2010GC003393.shtml}, author = {Langer, Gerald and Bode, Maya} } @article {Reid2011, title = {Coccolithophores: Functional biodiversity, enzymes and bioprospecting}, journal = {Marine Drugs}, volume = {9}, number = {4}, year = {2011}, note = {tex.mendeley-tags: 2011,rcc}, pages = {586{\textendash}602}, keywords = {2011, rcc, SBR$_\textrmP$hyto$_\textrmE$PPO}, doi = {10.3390/md9040586}, url = {http://www.mdpi.com/1660-3397/9/4/586/}, author = {Reid, Emma L and Worthy, Charlotte A and Probert, Ian and Ali, Sohail T and Love, John and Napier, Johnathan and Littlechild, Jenny A and Somerfield, Paul J and Allen, Michael J} } @article {Foresi2010, title = {Characterization of a nitric oxide synthase from the plant kingdom: NO generation from the green alga Ostreococcus tauri is light irradiance and growth phase dependent}, journal = {The Plant Cell}, volume = {22}, number = {11}, year = {2010}, note = {Edition: 2010/12/02 ISBN: 1532-298X (Electronic) 1040-4651 (Linking) tex.mendeley-tags: RCC745}, pages = {3816{\textendash}3830}, abstract = {The search for a nitric oxide synthase (NOS) sequence in the plant kingdom yielded two sequences from the recently published genomes of two green algae species of the Ostreococcus genus, O. tauri and O. lucimarinus. In this study, we characterized the sequence, protein structure, phylogeny, biochemistry, and expression of NOS from O. tauri. The amino acid sequence of O. tauri NOS was found to be 45\% similar to that of human NOS. Folding assignment methods showed that O. tauri NOS can fold as the human endothelial NOS isoform. Phylogenetic analysis revealed that O. tauri NOS clusters together with putative NOS sequences of a Synechoccocus sp strain and Physarum polycephalum. This cluster appears as an outgroup of NOS representatives from metazoa. Purified recombinant O. tauri NOS has a K(m) for the substrate l-Arg of 12 +/- 5 muM. Escherichia coli cells expressing recombinant O. tauri NOS have increased levels of NO and cell viability. O. tauri cultures in the exponential growth phase produce 3-fold more NOS-dependent NO than do those in the stationary phase. In O. tauri, NO production increases in high intensity light irradiation and upon addition of l-Arg, suggesting a link between NOS activity and microalgal physiology.}, keywords = {*Light, Amino Acid Sequence, Animals, Base Sequence, Chlorophyta/*enzymology/*growth \& development/phys, Humans, Isoenzymes/chemistry/genetics/metabolism, Models, Molecular, Molecular Sequence Data, Nitric Oxide Synthase/chemistry/genetics/*metaboli, Nitric Oxide/*biosynthesis, phylogeny, Plant Proteins/genetics/*metabolism, Protein Structure, rcc, RCC745, Sequence Alignment, Tertiary}, doi = {10.1105/tpc.109.073510}, url = {http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve\&db=PubMed\&dopt=Citation\&list_uids=21119059}, author = {Foresi, N and Correa-Aragunde, N and Parisi, G and Calo, G and Salerno, G and Lamattina, L} } @article {Frada2008, title = {The {\textquotedblleft}Cheshire Cat{\textquotedblright} escape strategy of the coccolithophore Emiliania huxleyi in response to viral infection}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {105}, year = {2008}, note = {tex.mendeley-tags: 2008,rcc,sbr?hyto?ppo}, pages = {15944{\textendash}15949}, abstract = {The coccolithophore is one of the most successful eukaryotes in modern oceans. The two phases in its haplodiploid life cycle exhibit radically different phenotypes. The diploid calcified phase forms extensive blooms, which profoundly impact global biogeochemical equilibria. By contrast, the ecological role of the noncalcified haploid phase has been completely overlooked. Giant phycodnaviruses ( viruses, EhVs) have been shown to infect and lyse diploid-phase cells and to be heavily implicated in the regulation of populations and the termination of blooms. Here, we demonstrate that the haploid phase of is unrecognizable and therefore resistant to EhVs that kill the diploid phase. We further show that exposure of diploid to EhVs induces transition to the haploid phase. Thus we have clearly demonstrated a drastic difference in viral susceptibility between life cycle stages with different ploidy levels in a unicellular eukaryote. Resistance of the haploid phase of provides an escape mechanism that involves separation of meiosis from sexual fusion in time, thus ensuring that genes of dominant diploid clones are passed on to the next generation in a virus-free environment. These {\^a}{\texteuro}{\oe}Cheshire Cat{\^a}{\texteuro} ecological dynamics release host evolution from pathogen pressure and thus can be seen as an opposite force to a classic {\^a}{\texteuro}{\oe}Red Queen{\^a}{\texteuro} coevolutionary arms race. In , this phenomenon can account for the fact that the selective balance is tilted toward the boom-and-bust scenario of optimization of both growth rates of calcifying cells and infectivity of EhVs.}, keywords = {2008, rcc, SBR$_\textrmP$hyto$_\textrmE$PPO, sbr?hyto?ppo}, doi = {10.1073/pnas.0807707105}, author = {Frada, Miguel and Probert, Ian and Allen, Michael J and Wilson, William H and de Vargas, Colomban} } @article {Jancek2008, title = {Clues about the genetic basis of adaptation emerge from comparing the proteomes of two Ostreococcus ecotypes (Chlorophyta, Prasinophyceae)}, journal = {Molecular Biology and Evolution}, volume = {25}, number = {11}, year = {2008}, note = {Edition: 2008/08/06 ISBN: 1537-1719 (Electronic) 0737-4038 (Linking) tex.mendeley-tags: RCC,rcc}, pages = {2293{\textendash}2300}, abstract = {We compared the proteomes of two picoplanktonic Ostreococcus unicellular green algal ecotypes to analyze the genetic basis of their adaptation with their ecological niches. We first investigated the function of the species-specific genes using Gene Ontology databases and similarity searches. Although most species-specific genes had no known function, we identified several species-specific functions involved in various cellular processes, which could be critical for environmental adaptations. Additionally, we investigated the rate of evolution of orthologous genes and its distribution across chromosomes. We show that faster evolving genes encode significantly more membrane or excreted proteins, consistent with the notion that selection acts on cell surface modifications that is driven by selection for resistance to viruses and grazers, keystone actors of phytoplankton evolution. The relationship between GC content and chromosome length also suggests that both strains have experienced recombination since their divergence and that lack of recombination on the two outlier chromosomes could explain part of their peculiar genomic features, including higher rates of evolution.}, keywords = {adaptation, Base Composition, Chlorophyta/*genetics, Ecosystem, Physiological/*genetics, Phytoplankton/genetics, Proteome/*genetics, rcc, Species Specificity}, doi = {10.1093/molbev/msn168}, url = {http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve\&db=PubMed\&dopt=Citation\&list_uids=18678753}, author = {Jancek, S and Gourbiere, S and Moreau, H and Piganeau, G} } @article {Six2008, title = {Contrasting photoacclimation strategies in ecotypes of the eukayotic picoplankter {\textexclamdown}i{\textquestiondown}Ostreococcus{\textexclamdown}/i{\textquestiondown}}, journal = {Limnology and Oceanography}, volume = {53}, year = {2008}, note = {tex.mendeley-tags: 2008,rcc,sbr?hyto$_\textrmd$ipo,sbr?hyto?app}, pages = {255{\textendash}265}, abstract = {Ostreococcus, the smallest known marine picoeukaryote, includes low- and high-light ecotypes. To determine the basis for niche partitioning between Ostreococcus sp. RCC809, isolated from the bottom of the tropical Atlantic euphotic zone, and the lagoon strain Ostreococcus tauri, we studied their photophysiologies under growth irradiances from 15 mmol photons m22 s21 to 800 mmol photons m22 s21 with a common nutrient replete regime. With increasing growth irradiance, both strains down-regulated cellular chlorophyll a and chlorophyll b (Chl a and Chl b) content, increased xanthophyll de-epoxidation correlated with nonphotochemical excitation quenching, and accumulated lutein. Ribulose-1,5-bisphosphate carboxylase/oxygenase content remained fairly stable. Under low-growth irradiances of 15{\textendash}80 mmol photons m22 s21, O. sp. RCC809 had equivalent or slightly higher growth rates, lower Chl a, a higher Chl b : Chl a ratio, and a larger photosystem II (PSII) antenna than O. tauri. O. tauri was more phenotypically plastic in response to growth irradiance, with a larger dynamic range in growth rate, Chl a, photosystem cell content, and cellular absorption cross-section of PSII. Estimating the amino acid and nitrogen costs for photoacclimation showed that the deep-sea oceanic O. sp. RCC809 relies largely on lower nitrogen cost changes in PSII antenna size to achieve a limited range of s-type light acclimation. O. sp. RCC809, however, suffers photoinhibition under higher light. This limited capacity for photoacclimation is compatible with the stable low-light and nutrient conditions at the base of the euphotic layer of the tropical Atlantic Ocean. In the more variable, high-nutrient, lagoon environment, O. tauri can afford to use a higher cost n-type acclimation of photosystem contents to exploit a wider range of light.}, keywords = {2008, rcc, SBR$_\textrmP$hyto$_\textrmD$PO, sbr?hyto$_\textrmd$ipo, sbr?hyto?app}, doi = {10.4319/lo.2008.53.1.0255}, author = {Six, C and Finkel, Z V and Rodriguez, F and Marie, D and Partensky, F and Campbell, D A} } @article {Robbens2007, title = {The complete chloroplast and mitochondrial DNA sequence of Ostreococcus tauri: organelle genomes of the smallest eukaryote are examples of compaction}, journal = {Molecular Biology and Evolution}, volume = {24}, number = {4}, year = {2007}, note = {tex.mendeley-tags: RCC,rcc}, pages = {956{\textendash}968}, abstract = {The complete nucleotide sequence of the mt (mitochondrial) and cp (chloroplast) genomes of the unicellular green alga Ostreococcus tauri has been determined. The mt genome assembles as a circle of 44,237 bp and contains 65 genes. With an overall average length of only 42 bp for the intergenic regions, this is the most gene-dense mt genome of all Chlorophyta. Furthermore, it is characterized by a unique segmental duplication, encompassing 22 genes and covering 44\% of the genome. Such a duplication has not been observed before in green algae, although it is also present in the mt genomes of higher plants. The quadripartite cp genome forms a circle of 71,666 bp, containing 86 genes divided over a larger and a smaller single-copy region, separated by 2 inverted repeat sequences. Based on genome size and number of genes, the Ostreococcus cp genome is the smallest known among the green algae. Phylogenetic analyses based on a concatenated alignment of cp, mt, and nuclear genes confirm the position of O. tauri within the Prasinophyceae, an early branch of the Chlorophyta.}, keywords = {rcc}, url = {http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve\&db=PubMed\&dopt=Citation\&list_uids=17251180}, author = {Robbens, S and Derelle, E and Ferraz, C and Wuyts, J and Moreau, H and Van de Peer, Y} } @article {Romari2004, title = {Composition and temporal variability of picoeukaryote communities at a coastal site of the English Channel from 18S rDNA sequences}, volume = {49}, number = {3}, year = {2004}, note = {Publication Title: Limnology and oceanography ISBN: 0024-3590 tex.mendeley-tags: Micromonas,RCC,rcc}, pages = {784{\textendash}798}, abstract = {Abstract We analyzed picoeukaryote assemblages at a French coastal site of the English Channel by sequencing cloned eukaryotic 18S rRNA genes in eight genetic libraries constructed from environmental samples (seven coastal , one estuarine) collected at different periods of the ...}, keywords = {Micromonas, rcc}, issn = {00243590}, doi = {10.4319/lo.2004.49.3.0784}, author = {Romari, Khadidja and Vaulot, Daniel} } @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} } @article {Jacquet2001, title = {Cell cycle regulation by light in Prochlorococcus strains}, journal = {Applied and Environmental Microbiology}, volume = {67}, number = {2}, year = {2001}, note = {tex.mendeley-tags: RCC,rcc}, pages = {782{\textendash}790}, abstract = {

The effect of light on the synchronization of cell cycling was investigated in several strains of the oceanic photosynthetic prokaryote Prochlorococcus using flow cytometry. When exposed to a light-dark (L-D) cycle with an irradiance of 25 mu mol of quanta m(-2) s(-1), the low-light-adapted strain SS 120 appeared to be better synchronized than the high-light-adapted strain PCC 9511. Submitting LD-entrained populations to shifts (advances or delays) in the timing of the "light on" signal translated to corresponding shifts in the initiation of the S phase, suggesting that this signal is a key parameter for the synchronization of population cell cycles. Cultures that were shifted from an L-D cycle to continuous irradiance showed persistent diel oscillations of flow-cytometric signals (light scatter and chlorophyll fluorescence) but with significantly reduced amplitudes and a phase shift. Complete darkness arrested most of the cells in the G(1), phase of the cell cycle, indicating that light is required to trigger the initiation of DNA replication and cell division. However, some cells also arrested in the S phase, suggesting that cell cycle controls in Prochlorococcus spp. are not as strict as in marine Synechococcus spp. Shifting Prochlorococcus cells from low to high irradiance translated quasi-instantaneously into an increase of cells in both the S and G(2) phases of the cell cycle and then into faster growth, whereas the inverse shift induced rapid slowing of the population growth rate. These data suggest a close coupling between irradiance levels and cell cycling in Prochloroeoccus spp.

}, keywords = {cyanobacteria, Equatorial Pacific, Gene Expression, Growth, Mediterranean Sea, North Atlantic, Photosynthetic Prokaryote, picoplankton, Populations, rcc, Synechococcus}, doi = {10.1128/AEM.67.2.782-790.2001}, author = {Jacquet, S and Partensky, F and Marie, D and Casotti, R and Vaulot, D} } @article {West2001, title = {Closely related Prochlorococcus genotypes show remarkably different depth distributions in two oceanic regions as revealed by in situ hybridization using 16S rRNA-targeted oligonucleotides}, journal = {Microbiology - UK}, volume = {147}, number = {7}, year = {2001}, note = {tex.mendeley-tags: RCC,rcc}, pages = {1731{\textendash}1744}, abstract = {An in situ hybridization method was applied to the identification of marine cyanobacteria assignable to the genus Procholorococcus using harseradish-peroxidase-labelled 16S rRNA-targeted oligonucleotide probes in combination with tyramide signal amplification (TSA). With this method very bright signals were obtained, in contrast to hybridizations with oligonucleotides monolabelled with fluorochromes, which failed to give positive signals. Genotype-specific oligonucleotides for high light (HL)- and low light (LL)adapted members of this genus were identified by 16S rRNA sequence analyses and their specificities confirmed in whole-cell hybridizations with cultured strains of Prochlorococcus marinus Chisholm et al., 1992, Prochlorococcus sp. and Synechococcus sp. In situ hybridization of these genotype-specific probes to field samples from stratified water bodies collected in the North Atlantic Ocean and the Red Sea allowed a rapid assessment of the abundance and spatial distribution of HL- and LL-adapted Prochlorococcus. In both oceanic regions the LL-adapted Prochlorococcus populations were localized in deeper water whereas the HL-adapted Prochlorococcus populations were not only distinct in each region but also exhibited strikingly different depth distributions, HLI being confined to shallow wafer in the North Atlantic, in contrast to HLII, which was present throughout the water column in the Red Sea.}, keywords = {Escherichia Coli, IDENTIFICATION, Marine Cyanobacterium, Nucleic Acid Probes, Photosynthetic Prokaryote, PICODIV, Populations, rcc, Ribosomal Rna, SEQUENCES, Tyramide Signal Amplification, Whole Cell Hybridization}, doi = {10.1099/00221287-147-7-1731}, author = {West, N J and Schonhuber, W A and Fuller, N J and Amann, R I and Rippka, R and Post, A F and Scanlan, D J} } @article {Moore1995, title = {Comparative physiology of Synechococcus and Prochlorococcus: influence of light and temperature on growth, pigments, fluorescence and absorptive properties}, journal = {Marine Ecology - Progress Series}, volume = {116}, year = {1995}, note = {tex.mendeley-tags: RCC,rcc}, pages = {259{\textendash}275}, keywords = {GROWTH RATE, Light, MARINE OPTICS, rcc, Synechococcus, temperature, \#PROCHLOROPHYTE}, doi = {10.3354/meps116259}, author = {Moore, L R and Goericke, R and Chisholm, S W} } @article {Simon1994, title = {Characterization of oceanic photosynthetic picoeukaryotes by flow cytometry analysis}, journal = {Journal of Phycology}, volume = {30}, year = {1994}, note = {tex.mendeley-tags: RCC,rcc}, pages = {922{\textendash}935}, keywords = {flow cytometry, hplc, pigments, rcc, RCC SBR$_\textrmP$hyto, \#PICOPLANKTON}, doi = {10.1111/j.0022-3646.1994.00922.x}, author = {Simon, N and Barlow, R G and Marie, D and Partensky, F and Vaulot, D} }