Marine metagenome
Ontology highlight
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PROVIDER: PRJNA132901 | ENA |
REPOSITORIES: ENA
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Project description:Lytic viruses have been implicated in the massive cellular lysis observed during algal blooms, through which they assume a prominent role in oceanic carbon and nutrient flows. Despite their impact on biogeochemical cycling, the transcriptional dynamics of these important oceanic events is still poorly understood. Here, we employ an oligonucleotide microarray to monitor host (Emiliania huxleyi) and virus (coccolithovirus) transcriptomic features during the course of E. huxleyi blooms induced in seawater-based mesocosm enclosures. Host bloom development and subsequent coccolithovirus infection was associated with a major shift in transcriptional profile. In addition to the expected metabolic requirements typically associated with viral infection (amino acid and nucleotide metabolism, as well as transcription- and replication-associated functions), the results strongly suggest that the manipulation of lipid metabolism plays a fundamental role during host-virus interaction. The results herein reveal the scale, so far massively underestimated, of the transcriptional domination that occurs during coccolithovirus infection in the natural environment. Six mesocosm enclosures were placed in the Raunefjorden (Western Norway coast) and filled with natural community water (in June 2008). Nutrient enrichment was applied in order to trigger the development of E. huxleyi blooms. The major transcriptomic features of those blooms and consequent viral infections were monitered through the use of an oligo microarray containing a total of 3571 gene probes; 2271 (63.6%) matching E. huxleyi ESTs, and 1300 (36.4%) matching EhV-86 and EhV-163 genomic sequences. Each microarray contains 5 technical replicates. Sampling of total RNA present in 2L of water (from each enclosure) was performed once a day from day 8 to day 16. For enclosures 2 and 3 other sampling points were taken, covering the complete dial-cycle (6h,12h,18h, and 24h).
2011-11-22 | E-GEOD-24341 | biostudies-arrayexpress
Project description:Lytic viruses have been implicated in the massive cellular lysis observed during algal blooms, through which they assume a prominent role in oceanic carbon and nutrient flows. Despite their impact on biogeochemical cycling, the transcriptional dynamics of these important oceanic events is still poorly understood. Here, we employ an oligonucleotide microarray to monitor host (Emiliania huxleyi) and virus (coccolithovirus) transcriptomic features during the course of E. huxleyi blooms induced in seawater-based mesocosm enclosures. Host bloom development and subsequent coccolithovirus infection was associated with a major shift in transcriptional profile. In addition to the expected metabolic requirements typically associated with viral infection (amino acid and nucleotide metabolism, as well as transcription- and replication-associated functions), the results strongly suggest that the manipulation of lipid metabolism plays a fundamental role during host-virus interaction. The results herein reveal the scale, so far massively underestimated, of the transcriptional domination that occurs during coccolithovirus infection in the natural environment.
2011-11-22 | GSE24341 | GEO
Project description:Background: Marine phytoplankton are responsible for 50% of the CO2 that is fixed annually worldwide and contribute massively to other biogeochemical cycles in the oceans. Diatoms and coccolithophores play a significant role as the base of the marine food web and they sequester carbon due to their ability to form blooms and to biomineralise. To discover the presence and regulation of short non-coding RNAs (sRNAs) in these two important phytoplankton groups, we sequenced short RNA transcriptomes of two diatom species (Thalassiosira pseudonana, Fragilariopsis cylindrus) and validated them by Northern blots along with the coccolithophore Emiliania huxleyi. Results: Despite an exhaustive search, we did not find canonical miRNAs in diatoms. The most prominent classes of sRNAs in diatoms were repeat-associated sRNAs and tRNA-derived sRNAs. The latter were also present in E. huxleyi. tRNA-derived sRNAs in diatoms were induced under important environmental stress conditions (iron and silicate limitation, oxidative stress, alkaline pH), and they were very abundant especially in the polar diatom F. cylindrus (20.7% of all sRNAs) even under optimal growth conditions. Conclusions: This study provides first experimental evidence for the existence of short non-coding RNAs in marine microalgae. Our data suggest that canonical miRNAs are absent from diatoms. However, the group of tRNA-derived sRNAs seems to be very prominent in diatoms and coccolithophores and may be used for acclimation to environmental conditions. RNA-seq study of sRNA populations in two species of diatoms using Illumina GAII high-throughput sequencing
2015-03-06 | E-GEOD-57987 | biostudies-arrayexpress
Project description:The abundant and widespread coccolithophore Emiliania huxleyi plays an important role in mediating CO2 exchange between the ocean and the atmosphere through its impact on marine photosynthesis and calcification. Here, we use long serial analysis of gene expression (SAGE) to identify E. huxleyi genes responsive to nitrogen (N) or phosphorus (P) starvation. Long SAGE is an elegant approach for examining quantitative and comprehensive gene expression patterns without a priori knowledge of gene sequences via the detection of 21-bp nucleotide sequence tags. E. huxleyi appears to have a robust transcriptional-level response to macronutrient deficiency, with 42 tags uniquely present or up-regulated twofold or greater in the N-starved library and 128 tags uniquely present or up-regulated twofold or greater in the P-starved library. The expression patterns of several tags were validated with reverse transcriptase PCR. Roughly 48% of these differentially expressed tags could be mapped to publicly available genomic or expressed sequence tag (EST) sequence data. For example, in the P-starved library a number of the tags mapped to genes with a role in P scavenging, including a putative phosphate-repressible permease and a putative polyphosphate synthetase. In short, the long SAGE analyses have (i) identified many new differentially regulated gene sequences, (ii) assigned regulation data to EST sequences with no database homology and unknown function, and (iii) highlighted previously uncharacterized aspects of E. huxleyi N and P physiology. To this end, our long SAGE libraries provide a new public resource for gene discovery and transcriptional analysis in this biogeochemically important marine organism. Keywords: Emiliania, gene expression, nutrients, SAGE, phosphate, nitrogen
2007-07-07 | GSE8376 | GEO
Project description:Background: Marine phytoplankton are responsible for 50% of the CO2 that is fixed annually worldwide and contribute massively to other biogeochemical cycles in the oceans. Diatoms and coccolithophores play a significant role as the base of the marine food web and they sequester carbon due to their ability to form blooms and to biomineralise. To discover the presence and regulation of short non-coding RNAs (sRNAs) in these two important phytoplankton groups, we sequenced short RNA transcriptomes of two diatom species (Thalassiosira pseudonana, Fragilariopsis cylindrus) and validated them by Northern blots along with the coccolithophore Emiliania huxleyi. Results: Despite an exhaustive search, we did not find canonical miRNAs in diatoms. The most prominent classes of sRNAs in diatoms were repeat-associated sRNAs and tRNA-derived sRNAs. The latter were also present in E. huxleyi. tRNA-derived sRNAs in diatoms were induced under important environmental stress conditions (iron and silicate limitation, oxidative stress, alkaline pH), and they were very abundant especially in the polar diatom F. cylindrus (20.7% of all sRNAs) even under optimal growth conditions. Conclusions: This study provides first experimental evidence for the existence of short non-coding RNAs in marine microalgae. Our data suggest that canonical miRNAs are absent from diatoms. However, the group of tRNA-derived sRNAs seems to be very prominent in diatoms and coccolithophores and may be used for acclimation to environmental conditions.
2015-03-06 | GSE57987 | GEO
Project description:The abundant and widespread coccolithophore Emiliania huxleyi plays an important role in mediating CO2 exchange between the ocean and the atmosphere through its impact on marine photosynthesis and calcification. Here, we use long serial analysis of gene expression (SAGE) to identify E. huxleyi genes responsive to nitrogen (N) or phosphorus (P) starvation. Long SAGE is an elegant approach for examining quantitative and comprehensive gene expression patterns without a priori knowledge of gene sequences via the detection of 21-bp nucleotide sequence tags. E. huxleyi appears to have a robust transcriptional-level response to macronutrient deficiency, with 42 tags uniquely present or up-regulated twofold or greater in the N-starved library and 128 tags uniquely present or up-regulated twofold or greater in the P-starved library. The expression patterns of several tags were validated with reverse transcriptase PCR. Roughly 48% of these differentially expressed tags could be mapped to publicly available genomic or expressed sequence tag (EST) sequence data. For example, in the P-starved library a number of the tags mapped to genes with a role in P scavenging, including a putative phosphate-repressible permease and a putative polyphosphate synthetase. In short, the long SAGE analyses have (i) identified many new differentially regulated gene sequences, (ii) assigned regulation data to EST sequences with no database homology and unknown function, and (iii) highlighted previously uncharacterized aspects of E. huxleyi N and P physiology. To this end, our long SAGE libraries provide a new public resource for gene discovery and transcriptional analysis in this biogeochemically important marine organism. Keywords: Emiliania, gene expression, nutrients, SAGE, phosphate, nitrogen Emiliania huxleyi CCMP 1516 was obtained from the Provasoli-Guillard Center for the Culture of Marine Phytoplankton, Bigelow Laboratories. Cultures were grown at 18°C on a 14 h:10 h light:dark cycle (140 µmol quanta m-2 s-1). Nitrogen and phosphate replete (Replete: 35 µM NO3- and 1.5 µM PO43-), low nitrogen (-N: 10 µM NO3-) and low phosphate (-P: 0 µM PO43-) cells were grown in f/50 medium without Si. Locally collected seawater was filtered (pore size, 0.2 µm) and autoclaved. Filter-sterilized inorganic nutrients, trace metals and vitamins (thiamin, biotin and B12) were added after autoclaving. The cells were grown in 8 L batch cultures. The growth of cultures was monitored daily by cell number counted on a hemacytometer, and by relative fluorescence using a Turner Designs AU Fluorometer. Replete cells were harvested in mid-log phase while –N and –P cells were harvested at the onset of stationary phase for SAGE analysis.
2007-07-07 | E-GEOD-8376 | biostudies-arrayexpress
Project description:Gene expression analysis of Emiliania huxleyi after 6, 12 and 24 hours of viral infection infected with the virus EhV-86 in comparison to an unifected culture.
2009-12-01 | E-MEXP-2382 | biostudies-arrayexpress
Project description:We performed single-cell transcriptome analysis (using MARS-seq) for the worldwide-distributed microalga Emiliania huxleyi during infection by its specific coccolithovirus. Our results provide insights into the expression programs and infection strategies of the large virus, and highlight the potential of single-cell RNA-sequencing for microbial eukaryotes in the lab and in the field.
2020-05-22 | GSE135429 | GEO
Project description:Transcription profiling of haploid and diploid Emiliania huxleyi growing into N limitation
2014-10-01 | E-MTAB-2274 | biostudies-arrayexpress
Project description:Investigation of the genetic diversity of Emiliania huxleyi, genomic DNA from 15 different strains were compared with the genomic DNA of the sequenced E. huxleyi strain CCMP1516. Gephyrocapsa oceanica and Isochrysis galbana as phylogenetic closely related taxa were used as out-groups.
2010-03-01 | E-MEXP-2388 | biostudies-arrayexpress