Project description:Non-targeted LC-MS/MS of PPL extracts from experimental and environmental seawater samples from coral reefs from Mo'orea (French Polynesia), collected in May 2019.
Project description:Non-targeted LC-MS/MS of PPL extracts comprised of DOM collected from the reef environment and coral and algae experimental incubations. Samples were primarily collected on Moorea, French Polynesia with a small subset collected from the Southern Line Islands.
Project description:Transcriptional profiling of gene responses in liver in the coral reef fish Pomacentrus moluccensis in response to different types of environmental stress: cold, heat, hypoxic and hyposmotic shock. Goal was to determine the common effects of different types of environmental stress on gene expression as well as responses unique to different stressors. Abstract from Kassahn et al. BMC Genomics (2007) 8:358 Background While our understanding of the importance of transcriptional regulation for biological function is continuously growing, we still know comparatively little about how environmentally-induced stress affects gene expression in vertebrates and how consistent transcriptional stress responses are across different types of environmental stress. Results In this study, we looked for a genetic measure of environmental stress and used a multi-stressor approach to identify components of a common stress response as well as components unique to different types of environmental stress. We exposed individuals of the coral reef fish Pomacentrus moluccensis to hypoxic, hyposmotic, cold and heat shock and measured the responses of approximately 16,000 genes in liver. We also compared winter and summer responses to heat shock to examine the capacity for such responses to vary with acclimation to different ambient temperatures. We identified a series of gene functions that were consistently involved in all stress responses examined here, suggesting common effects of stress on biological function. These common responses were achieved by the regulation of largely independent sets of genes and the responses of individual genes varied greatly across different stress types. However, we were able to identify groups of co-regulated genes, the genes within which shared similar functions. Given current estimates of climatic change, we were particularly interested in the response to prolonged heat exposure. In total, 324 gene loci were differentially expressed following exposure to heat over five days. The functions of these heat-responsive genes suggest that prolonged heat stress leads to oxidative stress and protein damage, challenge of the immune system, and a re-allocation of energy sources. Conclusion This is the first environmental genomic study to measure gene regulation in response to different environmental stressors in a natural population of a warm-adapted ectothermic vertebrate. This study offers insight into the effects of environmental stress on biological function and sheds light on the expected sensitivity of coral reef fishes to elevated temperatures in the future. Keywords: Stress response
Project description:Non-targeted LC-MS/MS of PPL extracts from experimental and environmental seawater samples from coral reefs from Mo'orea (French Polynesia), collected in May 2019.
Project description:Abstract Ocean warming elevates metabolic rates in marine ectotherms but often constrains energetic resources, causing an imbalance between supply and demand. Transient hypoxia is near-ubiquitous across the world’s coral reefs and may exacerbate this imbalance, yet its effects on the energetics of reef fishes remain poorly understood. In this study, we assess the metabolic costs incurred by a cryptobenthic reef fish exposed to oxygen fluxes measured on the world’s hottest coral reefs in the Arabian/Persian Gulf. Hypoxia-exposure induced an 8.67% increase in aerobic metabolic rate over the six hours following reoxygenation, and resulted in an estimated 2.87% increase in total daily metabolic rate (mg O2 kg -1 day-1). This energetic cost did not coincide with detectable changes in anaerobic metabolism but was accompanied by increased activity during reoxygenation and a strong, acute transcriptomic response in genes related to oxygen-sensing. Oxygen availability on the reefs declined below the threshold for inducing such energetic costs on over half (56.04%) of the days throughout the summer, potentially leading to substantial cumulative costs. Such energetic costs represent an additional and previously under-appreciated consequence of hypoxia in coral reef environments that may exacerbate the temperature-induced mismatches between energy supply and demand, a key balance affecting growth and fitness.