Project description:The experiment was designed to study the transcriptomic response of the centric diatom Skeletonema marinoi to the presence of cues from the grazer Calanus finmarchicus. Samples were collected in triplicate after 65 and 89 hours of exposure of diatom cells to the copepods. Control samples with no copepods were collected at the same time points.
Project description:A short-term microcosm experiment was conducted to evaluate the impact of wastewater discharge on coastal microbial communities. Coastal seawater was exposed to two types of treated wastewater: (i) unfiltered wastewater, containing nutrients, pollutants, and allochthonous microbes, and (ii) filtered wastewater, which retained only nutrients and pollutants while removing microbial components. Metaproteomic samples were collected from the coastal seawater prior to the experiment and from each experimental flask at the late exponential growth phase to assess microbial functional responses to wastewater exposure.
Project description:Physiological changes in response to environmental cues are not easily documented in pelagic copepods using traditional methods. Molecular biological tools provide new approaches to the investigation of difficult to sample organisms such as oceanic zooplankton. Here, we describe the development of a species-specific microarray for high-throughput studies of the physiological ecology of the North Atlantic copepod Calanus finmarchicus. An EST database was generated for this species using a normalized cDNA library derived from adult and sub-adult individuals from the Gulf of Maine. Sequence data were clustered into contigs and annotated using Blastx. Target transcripts were selected, and unique, 50 base-pair long, oligomer probes were designed and synthesized for 995 genes. Bioinformatic processing using Blast2GO software provided detailed information on gene function. The selected targets include a broad representation of biological processes, cellular components, and molecular functions. The microarray was tested on both experimental and ecological samples, i.e. food abundance and two morphotypes exhibiting distinct lipid stores, respectively. Differentially regulated transcripts were identified for both comparisons. Two comparisons were performed: 1) Lipid-rich (fat) and Lipid-poor (thin) morphotypes 2) Copepods kept under high food and low food experimental conditions
Project description:Thermal discharge-induced elevated seawater temperature alters richness, community composition and interactions of bacterioplankton assemblages in a coastal ecosystem.
Project description:Marine copepods are central to the productivity and biogeochemistry of marine ecosystems. Nevertheless, the direct and indirect effects of climate change on their metabolic functioning remain poorly understood. Here, we use metabolomics, the unbiased study of multiple low molecular weight organic metabolites, to examine how the physiology of Calanus spp. is affected by end-of-century global warming and ocean acidification scenarios. We report that the physiological stresses associated with incubation without food over a 5-day period greatly exceed those caused directly by seawater temperature or pH perturbations. This highlights the need to contextualise the results of climate change experiments by comparison to other, naturally occurring stressors such as food deprivation, which is being exacerbated by global warming. Protein and lipid metabolism were up-regulated in the food-deprived animals, with a novel class of taurine-containing lipids and the essential polyunsaturated fatty acids (PUFAs), eicosapentaenoic acid and docosahexaenoic acid, changing significantly over the duration of our experiment. Copepods derive these PUFAs by ingesting diatoms and flagellated microplankton respectively. Climate-driven changes in the productivity, phenology and composition of microplankton communities, and hence the availability of these fatty acids, therefore have the potential to influence the ability of copepods to survive starvation and other environmental stressors.
Project description:Comparative genomic hybridization of 9 Norwegian E. faecalis baby isolates with E. faecalis V583 as a reference strain using an E. faecalis V583 oligo array. Total gene content was analyzed by whole genome microarrays.