Project description:The fraction of dissolved dimethylsulfoniopropionate (DMSPd) converted by marine bacterioplankton into the climate-active gas dimethylsulfide (DMS) varies widely in the ocean, with the factors that determine this value still largely unknown. One current hypothesis is that the ratio of DMS formation:DMSP demethylation is determined by DMSP availability, with 'availability' in both an absolute sense (i.e., concentration in seawater) and in a relative sense (i.e., proportionally to other labile organic S compounds) being proposed as the critical factor. We investigated these models during an experimentally-induced phytoplankton bloom using an environmental microarray targeting DMSP-related gene expression in the Roseobacter group, a taxon of marine bacteria known to play an important role in the surface ocean sulfur cycle. The array consisted of 1,578 probes to 431 genes, including those previously linked to DMSP degradation as well as core genes common in sequenced Roseobacter genomes. The prevailing pattern of Roseobacter gene expression showed depletion of DMSP-related transcripts during the peak of the bloom, despite the fact that absolute concentrations and flux of DMSP-related compounds were increasing. A likely interpretation is that DMSPd was assimilated by Roseobacter populations in proportion to its relative abundance in the organic matter pool (the “relative sense” hypothesis), and that it is not taken up in preference to other sources of labile organic sulfur or carbon produced during the bloom. The relative investment of the Roseobacter community in DMSP demethylation did not predict the fractional conversion of DMSP to DMS, however, suggesting a complex regulatory process that may involve multiple fates of DMSPd.
Project description:The fraction of dissolved dimethylsulfoniopropionate (DMSPd) converted by marine bacterioplankton into the climate-active gas dimethylsulfide (DMS) varies widely in the ocean, with the factors that determine this value still largely unknown. One current hypothesis is that the ratio of DMS formation:DMSP demethylation is determined by DMSP availability, with 'availability' in both an absolute sense (i.e., concentration in seawater) and in a relative sense (i.e., proportionally to other labile organic S compounds) being proposed as the critical factor. We investigated these models during an experimentally-induced phytoplankton bloom using an environmental microarray targeting DMSP-related gene expression in the Roseobacter group, a taxon of marine bacteria known to play an important role in the surface ocean sulfur cycle. The array consisted of 1,578 probes to 431 genes, including those previously linked to DMSP degradation as well as core genes common in sequenced Roseobacter genomes. The prevailing pattern of Roseobacter gene expression showed depletion of DMSP-related transcripts during the peak of the bloom, despite the fact that absolute concentrations and flux of DMSP-related compounds were increasing. A likely interpretation is that DMSPd was assimilated by Roseobacter populations in proportion to its relative abundance in the organic matter pool (the “relative sense” hypothesis), and that it is not taken up in preference to other sources of labile organic sulfur or carbon produced during the bloom. The relative investment of the Roseobacter community in DMSP demethylation did not predict the fractional conversion of DMSP to DMS, however, suggesting a complex regulatory process that may involve multiple fates of DMSPd. DMSP-related gene expression in the Roseobacter group was investigated using an environmental microarray. Coastal seawater from the Gulf of Mexico was collected and dispensed into 20-L microcosms. Two replicate cubitainers were amended with nutrients (N and P) to stimulate phytoplankton bloom, while two untreated cubitainers served as controls. The microcosms were incubated at 27ºC in a temperature-controlled incubator on a 12 h light/dark cycle for total of 7 days. Ten RNA samples (Day 0: 2 conditions with 1 biological replicate each; Days 2 and 4: 2 conditions with 2 biological replicates each) were prepared for microarray hybridization. After total RNA extraction, rRNAs were removed and mRNA transcripts were amplified and labeled with Alexa Fluor 647. Two technical replicates were hybridized from each RNA sample. The microarray was designed based on selected Ruegeria pomeroyi DSS-3 genes and their orthologs in 12 other sequenced Roseobacter genomes. Probes were designed from the orthologs using the Hierarchical Probe Design (HPD) algorithm.
Project description:The Gram-negative photoheterotrophic bacterium Dinoroseobacter shibae is a member of the high abundant marine Roseobacter group. In the ocean, OMVs have about the same abundance as bacteria, a distinct depth distribution, and contain DNA from a variety of marine bacterial taxa. In the present study, we determined the abundance, size, and ultrastructure of membrane vesicles of D. shibae and analysed the protein inventory of the soluble and membrane fractions of cells and vesicles in order to study the origin of OMV membranes and content. The proteomic analyses were complemented by fatty acid analyses.
2020-12-16 | PXD014351 | Pride
Project description:Mutation Accumulation of three species affiliated with the Roseobacter group
Project description:Transcriptome profiles of an aerobic photosynthetic bacterium Roseobacter denitrificans OCh114 grown under different oxygen tension and light irradiation conditions were determined by NimbleGen Prokaryotic Expression array (12x135K).
2021-06-30 | GSE152336 | GEO
Project description:Draft Genome Sequences of Three Novel Representatives of the Roseobacter Group
| PRJNA713821 | ENA
Project description:Genomic study of Group A streptococcus infections in Greece
Project description:Four male patients were enrolled for this study in collaboration with the Cardiology Unit of Policlinico Tor Vergata-Fondazione PTV (Rome). The first group of patients has chronic coronary artery disease (CAD) confirmed by coronary angiography, the second group are subjects with clinically proven healthy coronary arteries (CTR). On our case study we have performed a genome-wide methylation study on genomic DNA bisulfite-converted and a miRNA-sequencing study using NextSeq 500 ILLUMINA platform. The methylation study showed different methylated regions (DMRs) and single CpG sites (DMCs) in patients sharing the same clinical and pathological features, allowing detecting distinctly different methylation patterns between CTR subjects and CAD patients. Moreover, miRNA-sequencing results displayed a differential expression of several significant miRNAs (p-value<0.05), defining a peculiar miRNAs profile in patients featuring the same clinical data. miRNA-sequencing and genome-wide methylation integreted results, showed hsa-miR-200c-3p down-regulated in CAD patients compared to control subjects (FC CAD=2.97 and p≤0.05) and with two hypermethylated sites (genomic coordinates: chr12:7073122-7073122 and chr12:7072599-7072599) in its promoter region (p-value=0.009). We extended the validation of these results on all case study (n=96; 24 CTR and 72 CAD).