Project description:An Autonomous Underwater Vehicle (AUV) and large volume underwater pumps were used to collect microbial biomass from offshore waters of the Sargasso Sea, from surface waters and into the deep ocean. Seawater collection was performed along a transect in the western North Atlantic Ocean beginning near Bermuda and ending off the coast of Massachusetts, capturing metabolic signatures from oligotrophic, continental margin, and productive coastal ecosystems.
Project description:The European clam, Ruditapes decussatus (Linnaeus, 1758) is a bivalve mollusc of the family Veneridae native to the European Atlantic and Mediterranean coastal waters. Its production is exclusively based on natural recruitment, which is subject to high annual fluctuations due to adversely affected by pollution and other environmental factors. Microarray analyses have been performed in four gonadal maturation stages of two higly productive Portuguese wild populations (Ria Formosa in South and Ria de Aveiro in North) characterized by different responses to spawning induction.
2014-06-03 | GSE51150 | GEO
Project description:nifH amplicon sequencing of western North Atlantic diazotrophs community
Project description:The European clam, Ruditapes decussatus (Linnaeus, 1758) is a bivalve mollusc of the family Veneridae native to the European Atlantic and Mediterranean coastal waters. Its production is exclusively based on natural recruitment, which is subject to high annual fluctuations due to adversely affected by pollution and other environmental factors. A microarray-based analysis was performed with the objectives of describe genomic feature of oocytes and identify potential markers of oocyte quality in the economically important European clam, Ruditapes decussatus. The oocytes of a total of 25 females from Ria de Aveiro, Western coast of Portugal, were selected for this study and their quality was estimated by early developmental success until D-larval rate, under controlled conditions.
Project description:Although N2 fixation can occur in free-living cyanobacteria, the unicellular endosymbiotic cyanobacterium Candidatus Atelocyanobacterium thalassa (UCYN-A) is considered to be a dominant N2-fixing species in marine ecosystems. Four UCYN-A sublineages are known from partial nitrogenase (nifH) gene sequences. However, few studies have investigated their habitat preferences and regulation by their respective hosts in open-ocean versus coastal environments. Here, we compared UCYN-A transcriptomes from oligotrophic open-ocean versus nutrient-rich coastal waters. UCYN-A1 metabolism was more impacted by habitat changes than UCYN-A2. However, across habitats and sublineages genes for nitrogen fixation and energy production were highly transcribed. Curiously these genes, critical to the symbiosis for the exchange of fixed nitrogen for fixed carbon, maintained the same schedule of diel expression across habitats and UCYN-A sublineages, including UCYN-A3 in the open-ocean transcriptomes. Our results undersore the importance of nitrogen fixation in UCYN-A symbioses across habitats, with consequences for community interaction and global biogeochemical cycles.
Project description:In the North Sea and adjacent North Atlantic coastal areas fish experience relatively high levels of persistent organic pollutants. The aim of this study is to compare the mode of actions of environmentally relevant concentrations of halogenated compounds and their mixtures in Atlantic cod. Juvenile male cod were fed mixtures of chlorinated (PCBs, DDT analogs, chlordane, lindane and toxaphene), brominated (PBDEs) and fluorinated (Perfluorooctanesulfonate/PFOS) compounds for one month. One group received a mixture of all three compounds. Transcriptome analysis of liver samples was performed to identify the main affected pathways. Accumulated levels of chemicals in cod liver reflected concentrations found in wild fish. Pathway analysis revealed that the treatment effects by each of the three groups of chemicals (chlorinated, brominated and fluorinated) converged on activation of the unfolded protein response (UPR). The results of our transcriptomics analysis suggest that the UPR pathway is a sensitive common target of halogenated organic environmental pollutants
Project description:The European clam, Ruditapes decussatus (Linnaeus, 1758), is a bivalve mollusc of the family Veneridae native to the European Atlantic and Mediterranean coastal waters. Its production is exclusively based on natural recruitment, which is subject to high annual fluctuations due to adversely affected by pollution and other environmental factors. In the present study, oocytes from 15 females were collected in Ria de Aveiro (Western coast of Portugal) and microarray analysis was performed in order to investigate gene expression profiles characterizing naturally released oocytes and ovarian oocytes obtained by stripping. Released oocytes were obtained in the context of a study carried out by de Sousa and co-workers (GSE54954: de Sousa et al., 2014, submitted) focusing on expression profiles characterizing oocytes with different quality level. In particular, to compare stripped and spawned oocytes, a total of 10 samples (5 with bad/intermediate hatching rate and 5 with good hatching rate) out of the 25 analyzed in the previous study (GSE54954), and 5 new pools of stripped oocytes, have been analyzed by microarray analyses.
2014-11-05 | GSE58906 | GEO
Project description:Bacterial community composition in western North Atlantic
Project description:The European clam, Ruditapes decussatus (Linnaeus, 1758) is a bivalve mollusc of the family Veneridae native to the European Atlantic and Mediterranean coastal waters. Its production is exclusively based on natural recruitment, which is subject to high annual fluctuations due to adversely affected by pollution and other environmental factors. Microarray analyses have been performed in four gonadal maturation stages of two higly productive Portuguese wild populations (Ria Formosa in South and Ria de Aveiro in North) characterized by different responses to spawning induction. Twenty clams (Ruditapes decussatus)were monthly sampled between July 2011 and July 2012 in two different Portuguese wild populations: Ria Formosa and Ria de Aveiro. At each sampling date the gonads of the collected clams were immediately dissected for RNA extraction and fixed for histological analysis. Total RNA was isolated using Extract-all (Eurobio) procedure. RNA quality and integrity was controlled on the Agilent bioanalyzer using RNA nanochips and Agilent RNA 6000 nanoreagents (Agilent Technologies, Waldbronn, Germany). RNA concentrations were measured at 260 nm using a ND-1000 spectrophotometer (Nanodrop Technologies) using the conversion factor 1 OD = 40 mg/mL total RNA. Samples were stored at -80°C until further use. Gene expression profiling was performed using an R.decussatus oligo-DNA microarray of 59,951 probes based on single-colour detection (Cyanine-3 only). Microarrays were scanned with Agilent scanner G2565BA at a resolution of 2 microns; all slides were scanned twice at two different sensitivity settings (XDRHi 100% and XDRLo 10%); the scanner software created a unique ID for each pair of XDR scans and saved it to both scan image files. FeatureExtraction v10.7.3.1 used XDR ID to link the pairs of scans together automatically when extracting data. The signal left after all the FE processing steps have been completed is ProcessedSignal that contains the Multiplicatively Detrended, Background-Subtracted Signal.