Project description:In the seabed, chemical defences mediate inter- and intraspecific interactions and may determine organisms’ success, shaping the diversity and function of benthic communities. Sponges represent a prominent example of chemically-defended marine organisms with great ecological success. The ecological factors controlling the production of their defensive compounds and the evolutionary forces that select for these defences remain little understood. Each sponge species produces a specific and diverse chemical arsenal with fish-deterrent, antifouling and antimicrobial properties. However, some small animals (mesograzers), mainly sea slugs, have specialized in living and feeding on sponges. Feeding on chemically-defended organisms provides a strategy to avoid predators, albeit the poor nutritional value of sponges. In order to investigate the mechanisms that control sponge chemical defence, with particular focus on the response to specialist grazers, we investigated the interaction between the sponge Aplysina aerophoba and the sea slug Tylodina perversa. Here we performed controlled experiments and collected sponge samples at different time points (3h, 1d and 6d after treatment). To further elucidate if the sponge response is specific to grazing by T. perversa, we also included a treatment in which sponges were mechanically damaged with a scalpel. We compared gene expression between treatments based on RNA-Seq data.
Project description:The Crown-of-thorns starfish (COTS) Acanthaster planci feeds on hard corals and its outbreaks are a major cause of destruction of coral communities on the Australian Great Barrier Reef. Whilst population booms and the social behaviour of COTS have been well studied, little is known about the neural mechanisms underlying COTS metabolism and behaviour. One of the major classes of chemical messengers that regulate metabolic and behavioural processes in animals are neuropeptides. Here, we have analysed COTS genome and transcriptome sequence data to identify neuropeptide precursor proteins in this species. Mass spectrometry was employed to identify neuropeptides extracted from radial nerve cords. Forty-nine neuropeptide precursors were identified, including homologs of neuropeptide signaling systems that are evolutionarily conserved throughout the Bilateria.
Project description:Iron-sulfur minerals such as pyrite are found in many marine benthic habitats. At deep-sea hydrothermal vent sites they occur as massive sulfide chimneys. Hydrothermal chimneys formed by mineral precipitation from reduced vent fluids upon mixing with cold oxygenated sea water. While microorganisms inhabiting actively venting chimneys and utilizing reduced compounds dissolved in the fluids for energy generation are well studied, only little is known about the microorganisms inhabiting inactive sulfide chimneys. We performed a comprehensive meta-proteogenomic analysis combined with radiometric dating to investigate the diversity and function of microbial communities found on inactive sulfide chimneys of different ages from the Manus Basin (SW Pacific). Our study sheds light on potential lifestyles and ecological niches of yet poorly described bacterial clades dominating inactive chimney communities.
Project description:<p>Benthic organisms sustain coral reefs through their growth and metabolism, but less is known about how their released metabolites influence reef seawater microorganisms. To investigate metabolite composition of benthic exudates and their ecological significance for reef microbial communities, we harvested exudates from six species of Caribbean benthic organisms including stony corals, octocorals, and an invasive encrusting algae, and subjected these exudates to untargeted and targeted metabolomics approaches using liquid chromatography-mass spectrometry. Incubations with reef seawater microorganisms were conducted to monitor changes in microbial community composition using 16S rRNA gene sequencing and abundance in relation to exudate source and three specific metabolites. Exudates tended to be enriched in amino acids, nucleosides, and vitamins, indicating that benthic organisms contribute labile organic matter to reefs. The phytohormone indole-3-acetic acid was detected in octocoral exudates, suggesting that this metabolite facilitates microbial interactions within and outside of benthic organisms. Exudate compositions were species-specific and significantly enriched in the indole class of metabolites. Microbial abundances and specific microbial taxa responded differently in relation to exudates from stony corals and octocorals, demonstrating the link between benthic organismal composition, metabolite exudates, and microbial growth. Conversely, microbial communities did not respond to additions of the individual metabolites, suggesting that reef microorganisms likely provide diverse metabolite pools that support microbial growth. This work provides novel information about the metabolites released from common Caribbean benthic organisms and indicates that the recent shifts in benthic composition from stony to octocorals alter exudate composition and likely impact microbial community composition and function on coral reefs.</p><p><br></p><p><strong>UPLC-MS Metabolite collection incubation assays</strong> are reported in the current study <strong>MTBLS2855</strong></p><p><strong>UPLC-MS Metabolite uptake incubation assay</strong> is reported in <a href='https://www.ebi.ac.uk/metabolights/editor/study/MTBLS3286' rel='noopener noreferrer' target='_blank'><strong>MTBLS3286</strong></a></p>
Project description:<p>Benthic organisms sustain coral reefs through their growth and metabolism, but less is known about how their released metabolites influence reef seawater microorganisms. To investigate metabolite composition of benthic exudates and their ecological significance for reef microbial communities, we harvested exudates from six species of Caribbean benthic organisms including stony corals, octocorals, and an invasive encrusting algae, and subjected these exudates to untargeted and targeted metabolomics approaches using liquid chromatography-mass spectrometry. Incubations with reef seawater microorganisms were conducted to monitor changes in microbial community composition using 16S rRNA gene sequencing and abundance in relation to exudate source and three specific metabolites. Exudates tended to be enriched in amino acids, nucleosides, and vitamins, indicating that benthic organisms contribute labile organic matter to reefs. The phytohormone indole-3-acetic acid was detected in octocoral exudates, suggesting that this metabolite facilitates microbial interactions within and outside of benthic organisms. Exudate compositions were species-specific and significantly enriched in the indole class of metabolites. Microbial abundances and specific microbial taxa responded differently in relation to exudates from stony corals and octocorals, demonstrating the link between benthic organismal composition, metabolite exudates, and microbial growth. Conversely, microbial communities did not respond to additions of the individual metabolites, suggesting that reef microorganisms likely provide diverse metabolite pools that support microbial growth. This work identifies, quantifies, and compares metabolites released from common Caribbean benthic organisms and indicates that recent shifts in benthic composition from stony to octocorals alter exudate composition and likely impact microbial community composition and function on coral reefs.</p><p><br></p><p><strong>UPLC-MS Metabolite uptake incubation assay</strong> is reported in the current study <strong>MTBLS3286</strong></p><p><strong>UPLC-MS Metabolite collection incubation assays</strong> are reported in <a href='https://www.ebi.ac.uk/metabolights/editor/study/MTBLS2855' rel='noopener noreferrer' target='_blank'><strong>MTBLS2855</strong></a></p>