Project description:This is a dataset associated with an article in the journal Metabolomics titled "Metabolomic richness and fingerprints of deep-sea coral species and populations."
Abstract:
Introduction: From shallow water to the deep sea, corals form the basis of diverse communities with significant ecological and economic value. These communities face many anthropogenic stressors including energy and mineral extraction activities, ocean acidification and rising sea temperatures. Corals and their symbionts produce a diverse assemblage of compounds that may help provide resilience to some of these stressors. Objectives: We aim to characterize the metabolomic diversity of deep-sea corals in an ecological context by investigating patterns across space and phylogeny. Methods: We applied untargeted Liquid Chromatography-Mass Spectrometry to examine the metabolomic diversity of the deep-sea coral, Callogorgia delta, across three sites in the Northern Gulf of Mexico as well as three other deep-sea corals, Stichopathes sp., Leiopathes glaberrima, and Lophelia pertusa, and a shallow-water species, Acropora palmata. Results: Different coral species exhibited distinct metabolomic fingerprints and differences in metabolomic richness including core ions unique to each species. C. delta was generally least diverse while Lophelia pertusa was most diverse. C. delta from different sites had different metabolomic fingerprints and metabolomic richness at individual and population levels, although no sites exhibited unique core ions. Two core ions unique to C. delta were putatively identified as diterpenes and thus may possess a biologically important function. Conclusion: Deep-sea coral species have distinct metabolomic fingerprints and exhibit high metabolomic diversity at multiple scales which may contribute to their capabilities to respond to both natural and anthropogenic stressors, including climate change.
Project description:A total of 10 specimens of Alcyonacea corals were collected at depths ranging from 905 m to 1 633 m by the manned submersible Shenhai Yongshi during two cruises in the South China Sea (SCS). Based on mitochondrial genomic characteristics, morphological examination, and sclerite scanning electron microscopy, the samples were categorized into four suborders (Calcaxonia, Holaxonia, Scleraxonia, and Stolonifera), and identified as 9 possible new cold-water coral species. Assessments of GC-skew dissimilarity, phylogenetic distance, and average nucleotide identity (ANI) revealed a slow evolutionary rate for the octocoral mitochondrial sequences. The nonsynonymous ( Ka) to synonymous ( Ks) substitution ratio ( Ka/ Ks) suggested that the 14 protein-coding genes (PCGs) were under purifying selection, likely due to specific deep-sea environmental pressures. Correlation analysis of the median Ka/ Ks values of five gene families and environmental factors indicated that the genes encoding cytochrome b (cyt b) and DNA mismatch repair protein ( mutS) may be influenced by environmental factors in the context of deep-sea species formation. This study highlights the slow evolutionary pace and adaptive mechanisms of deep-sea corals.
Project description:Scleractinian corals acquire autotrophic nutrients via the photosynthetic activity of their symbionts and the subsequent transfer of photosynthates. Zooplankton predation by the animal (heterotrophy) is an additional food source. Under stress events, corals loose their symbionts, a phenomena known as bleaching, which eventually leads to starvation, unless corals increase their heterotrophic capacities. Molecular mechanisms by which heterotrophy sustains metabolism in stressed corals remain elusive. Here for the first time, we identify specific genes expressed in heterotrophically fed and unfed corals maintained under normal and light-stress conditions inducing bleaching. Physiological parameters and gene expression profiling showed ominously that fed corals better resisted the stress than unfed corals, by presenting less oxidative damage and protein/DNA degradation. Light stressed and unfed/starved corals (HLS) up-regulated by 140 and 13 times two genes (CP2U1 and CP1A2), which belong to the Cytochrome P450 superfamily, while these genes remained almost unchanged in fed corals (HLF). Other genes of redox regulation, DNA damage response, molecular chaperones, and protein degradation were also up-regulated in HLS corals, presenting higher bleaching, and strong decrease of the photosynthesis performance compared to HLF corals. Several pivotal genes associated with the calcification apparatus such as carbonic anhydrases, calcium-transporting ATPase, calcium channel subunit, and bone morphogenetic proteins (BMPs), were significantly down-regulated only in HLS corals. A parallel decrease in the calcification rates of these later corals was also observed. All together, these results show clearly that heterotrophy helps preventing oxidative stress in corals, and thus avoid the cascade of metabolic problems downstream this stress.
Project description:Deep-sea corals are found on hard substrates on seamounts and continental margins worldwide at depths of 300 to approximately 3,000 m. Deep-sea coral communities are hotspots of deep ocean biomass and biodiversity, providing critical habitat for fish and invertebrates. Newly applied radiocarbon age dates from the deep water proteinaceous corals Gerardia sp. and Leiopathes sp. show that radial growth rates are as low as 4 to 35 mum year(-1) and that individual colony longevities are on the order of thousands of years. The longest-lived Gerardia sp. and Leiopathes sp. specimens were 2,742 years and 4,265 years, respectively. The management and conservation of deep-sea coral communities is challenged by their commercial harvest for the jewelry trade and damage caused by deep-water fishing practices. In light of their unusual longevity, a better understanding of deep-sea coral ecology and their interrelationships with associated benthic communities is needed to inform coherent international conservation strategies for these important deep-sea habitat-forming species.
Project description:Sulfur metabolism in the deep-sea cold seep has been mentioned to have an important contribution to the biogeochemical cycle of sulfur in previous studies. And sulfate reducing bacteria have also been considered to be a dominant microbial population in the deep-sea cold seep and play a crucial role in this process. However, most of sulfate reducing bacteria from cold seep still cannot be purely cultured under laboratory conditions, therefore the actual sulfur metabolism pathways in sulfate reducing bacteria from the deep-sea cold seep have remained unclear. Here, we isolate and pure culture a typical sulfate reducing bacterium Desulfovibrio marinus CS1 from the sediment sample of the deep-sea cold seep in the South China Sea, which provides a probability to understand the sulfur metabolism in the cold seep.