Project description:Construction of a comprehensive spectral library for the coral reef fish, Acanthochromis polyacanthus, from both DIA and DDA MS runs. The spectral library was then used to quantify proteomes of individual fish exposed to different environmental conditions including ocean acidification and ocean warming. Proteomes were measured for both liver and brain tissue and differential expression between environmental conditions was analyzed.
Project description:The association with photosymbiotic algae is crucial for the proliferation of many coral reef organisms, but increases their sensitivity to environmental changes. Large benthic foraminifera (LBF) are a diverse group of carbonate producers harboring algal photosymbionts. They act as key ecological engineers and are widely used as bioindicators. As in corals, elevated temperatures and light intensities are known to induce bleaching in LBF, but the combined effects of ocean acidification and warming remain unclear. To shed light into the adaptive physiology of LBF, we linked the assessment of the holobiont and photosymbiont physiological condition (mortality, growth, coloration, and chlorophyll a) to a bottom-up proteomics approach that allows the examination of cellular responses of host and symbionts simultaneously. In a two-months experiment, we exposed Amphistegina lobifera to the combined effects of ocean acidification (400, 1000 and 2800 ppm pCO2) and warming (28-control and 31°C). More than 1,000 proteins were identified by label-free mass spectrometry-based whole proteome analysis and assigned to the host or photosymbionts. Photopigment concentrations declined in response to elevated pCO2, visible by discoloration. These indicate the reduction of photosymbiont densities under ocean acidification, despite the fertilizing effects suggested for high inorganic carbon availability, and imply metabolic adjustments. Increases of proteolytic proteins suggest active host regulation of photosymbiont density in order to maintain homeostasis with its algal photosymbionts. Growth rates, however, were unaffected by elevated pCO2 levels at control temperatures, but high pCO2 levels (2800 ppm, pH 7.52) combined with thermal stress (31°C) impaired growth, though mortality and shell dissolution was negligible. While growth was unaffected by intermediate pCO2 levels (1000 ppm, pH 7.98) combined with ocean warming, this treatment induced the most distinct proteome responses. These include the regulation of ion transporters and host cytoplasmic proteins that likely abet calcification under ocean acidification. This study reveals a highly complex cellular response in both the host and the photosymbiont, which appears to facilitate a high resilience potential of A. lobifera to end of the century ocean conditions. Nevertheless, our results imply that when pCO2 levels rise above 1000 ppm during persistent ocean warming or extreme heating events these adaptive mechanisms become disrupted.
Project description:Rising atmospheric CO2 concentrations are leading to ocean acidification, altering the inorganic carbon buffer system with consequences for marine organisms. Here we applied RNA-seq and iTRAQ quantification to investigate the potential impacts of ocean acidification on the temperate coastal marine diatom Skeletonema marinoi.
Project description:Increasing atmospheric CO2 raises sea surface temperatures and results in ocean acidification, which will impact upon calcifying marine organisms, such as the commercially and ecologically important Pacific oyster (Crassostrea gigas). Larval stages of development are particularly sensitive to such stressors and may represent population bottlenecks. A two-dimensional electrophoresis (2-DE) proteomic approach was used to investigate the response of 40 hour C. gigas larvae to ocean acidification and warming, and to relate protein expression to phenotypic variation in size and calcification. Larvae were reared at two pHs (8.1 and 7.9) and two temperatures (20°C and 22°C), and comparisons carried out between the four possible treatment combinations. In total 22 differentially expressed spots, corresponding to 18 proteins, were identified by nano-liquid chromatography tandem mass spectrometry. These proteins had roles in metabolism, biomineralisation, intra- and extra-cellular matrix formation and as molecular chaperones. Thirteen of these spots responded to acidification, of which 11 showed reduced expression during acidification. Declines in ATP synthase, arginine kinase and other metabolic proteins suggest metabolic depression occurred during acidification and reduced protein synthesis. In contrast, 6 of 7 proteins that were differentially expressed during warming showed increased expression. Among these were molecular chaperones including protein disulphide isomerase (PDI) and Grp78. Concurrent acidification and warming appeared to mitigate some proteomic changes and negative phenotypic effects observed in acidification at 20°C; however, differential expression of nine proteins and other temperature-independent effects on calcification phenotypes suggest that larval responses to multiple stressors will be complex.
2022-03-01 | PXD002316 | Pride
Project description:Ocean warming and acidification effects on Antarctic fish embryos
Project description:In this study we investigated how changes in pH and ocean chemistry consistent with the scenarios of the Intergovernmental Panel on Climate Change (IPCC) drive major changes in gene expression, respiration, photosynthesis and symbiosis of the coral, Acropora millepora, long before they affect biomineralization. Changes in gene expression were consistent with metabolic suppression, an increase in oxidative stress, apoptosis and symbiont loss. Other expression patterns demonstrated up-regulation of membrane transporters, as well as the regulation of genes involved in membrane cytoskeletal interactions and cytoskeletal remodeling. These widespread changes in gene expression emphasize the need to expand future studies of ocean acidification to include a wider spectrum of cellular processes, many of which may occur well before impacts on calcification. We applied a reference microarray design for the experiment outlined in the study, which was a three condition experiment of ocean acidification: control pH 8.0-8.2, medium pH 7.8-7.9 and high pH 7.6-7.7, and across three time points: time zero, day 1 and day 28. Samples from time zero and control treatments were used to generate the reference sample for the microarray hybridization experiments. A total of 27 microarrays were used in the entire experiment, 3 biological replicates per treatment and timepoint. Reference samples in each array was labeled with Cy3, and the actual experimental samples with Cy5.
Project description:Crustose coralline algae (CCA) are calcifying red macroalgae that play important ecological roles including stabilisation of reef frameworks and provision of settlement cues for a range of marine invertebrates. Previous research into the responses of CCA to ocean warming (OW) and ocean acidification (OA) have found magnitude of effect to be species-specific. Response to OW and OA could be linked to divergent underlying molecular processes across species. Here we show Sporolithon durum, a species that exhibits low sensitivity to climate stressors, had little change in metabolic performance and did not significantly alter the expression of any genes when exposed to temperature and pH perturbations. In contrast, Porolithon onkodes, a major coral reef builder, reduced photosynthetic rates and had a labile transcriptomic response with over 400 significantly differentially expressed genes, with differential regulation of genes relating to physiological processes such as carbon acquisition and metabolism. The differential gene expression detected in P. onkodes implicates possible key metabolic pathways, including the pentose phosphate pathway, in the stress response of this species. We suggest S. durum is more resistant to OW and OA than P. onkodes, which demonstrated a high sensitivity to climate stressors and may have limited ability for acclimatisation. Understanding changes in gene expression in relation to physiological processes of CCA could help us understand and predict how different species will respond to, and persist in, future ocean conditions predicted for 2100.
Project description:In this study we investigated how changes in pH and ocean chemistry consistent with the scenarios of the Intergovernmental Panel on Climate Change (IPCC) drive major changes in gene expression, respiration, photosynthesis and symbiosis of the coral, Acropora millepora, long before they affect biomineralization. Changes in gene expression were consistent with metabolic suppression, an increase in oxidative stress, apoptosis and symbiont loss. Other expression patterns demonstrated up-regulation of membrane transporters, as well as the regulation of genes involved in membrane cytoskeletal interactions and cytoskeletal remodeling. These widespread changes in gene expression emphasize the need to expand future studies of ocean acidification to include a wider spectrum of cellular processes, many of which may occur well before impacts on calcification.