Project description:Sponges are efficient filter feeders, removing significant portions of particulate and dissolved organic matter (POM, DOM) from the water column. While the assimilation and respiration of POM and DOM by sponges and their abundant microbial symbiont communities have received much attention, there is virtually no information on the impact of sponge holobiont metabolism on the composition of DOM at a molecular-level. We applied untargeted and targeted metabolomics techniques to characterize DOM in seawater samples prior to entering the sponge (inhalant reef water), in samples exiting the sponge (exhalent seawater), and in samples collected just outside the reef area (off reef seawater). Samples were collected from two sponge species, Ircinia campana and Spheciospongia vesparium, on a near-shore hard bottom reef in the Florida Keys. Metabolic profiles generated from untargeted metabolomics analysis indicated that many more compounds were enhanced in the exhalent samples than in the inhalant samples. Targeted metabolomics analysis revealed differences in diversity and concentration of metabolites between exhalent and off reef seawater. For example, most of the nucleosides were enriched in the exhalent seawater, while the aromatic amino acids, caffeine and the nucleoside xanthosine were elevated in the off reef water samples. Although the metabolic profile of the exhalent seawater was unique, the impact of sponge metabolism on the overall reef DOM profile was spatially limited in our study. There were also no significant differences in the metabolic profiles of exhalent water between the two sponge species, potentially indicating that there is a characteristic DOM profile in the exhalent seawater of Caribbean sponges. Additional work is needed to determine whether the impact of sponge DOM is greater in habitats with higher sponge cover and diversity. This work provides the first insight into the molecular-level impact of sponge holobiont metabolism on reef DOM and establishes a foundation for future experimental studies addressing the influence of sponge-derived DOM on chemical and ecological processes in coral reef ecosystems.
Project description:The interaction of animals with microbes relies on the specific recognition of microbial-derived molecules by receptors of the immune system. Sponges (phylum Porifera), as sister group of the Eumetazoa, provide insights into conserved mechanisms for animal-microbe crosstalk, but empirical data is limited. Here we aimed to characterize the immune response of sponges upon microbial stimuli by RNA-Seq. Two sponges species from the Mediterranean Sea, Aplysina aerophoba and Dysidea avara, were challenged with microbial-associated molecular patterns (lipopolysaccharide and peptidoglycan) or sterile artificial seawater (control) in aquarium experiments. Sponge tissue samples were collected 1h, 3h, and 5h after treatment. The response of the sponges to the treatments was assessed by differential gene expression analysis of RNA-Seq data. For each species, we compared the transcriptomic profiles of the samples in MAMP treatment to control within each time point.
Project description:Marine sponges are essential for coral reefs to thrive and harbour a diverse microbiome that is thought to contribute to host health. Although the overall function of sponge symbionts has been increasingly described, in-depth characterisation of each taxa remains challenging, with many sponge species hosting up to 3,000 distinct microbial species. Recently, the sponge Ianthella basta has emerged as a model organism for symbiosis research, hosting only three dominant symbionts: a Thaumarchaeotum, a Gammaproteobacterium, and an Alphaproteobacterium and a range of other minor taxa. Here, we retrieved metagenome assembled genomes (MAGs) for >90% of I. basta’s microbial community which allowed us to make a complete metabolic reconstruction of the sponge’s microbiome, identifying metabolic complementarity between microbes, as well as the importance of symbionts present in low abundance. We also mined the metagenomes for putative viral sequences, highlighting the contribution of viruses to the overall metabolism of the sponge, and complement this data with metaproteomic sequencing to identify active metabolic pathways in both prokaryotes and viruses. This data now allows us to use I. basta as a model organism for studying host-microbe interactions and provides a basis for future (genomic) manipulative experiments.
Project description:Tropical lagoon-inhabiting organisms live in highly irradiated ecosystems and are particularly susceptible to thermal stress resulting from climate change. However, despite living close to their thermal maxima, stress response mechanisms found in these organisms are poorly understood. We used a novel physiological-proteomic approach for sponges to describe the stress response mechanisms of the lagoon-inhabiting sponge Amphimedon navalis, when exposed to elevated seawater temperatures of +2 oC and +4 oC relative to a 26 oC ambient temperature for four weeks. After four weeks of thermal exposure, the buoyant weight of the sponge experienced a significant decline, while its pumping rates and oxygen consumption rates significantly increased. Proteome dynamics revealed 50 differentially abundant proteins in sponges exposed to elevated temperature, suggesting that shifts in the sponge proteome were potential drivers of physiological dysfunction. Thermal stress promoted an increase in detoxification proteins, such as catalase and glutathione-S-transferase, suggesting that an excess of reactive oxygen species in sponge cells were likely responsible for the significant increase in oxygen consumption. Elevated temperature also disrupted cellular growth and cell proliferation, promoting the loss of sponge biomass, and the high abundance of multiple alpha-tubulin chain proteins also indicated an increase in cytoskeletal activities within sponge cells, which may have induced the increase in sponge pumping rate. Our results show that sustained thermal exposure in susceptible lagoonal sponges may induce significant disruption of cellular homeostasis leading to physiological dysfunction, and that a combined physiological-proteomic approach may provide new insights into physiological functions and cellular processes occurring in sponges.
2021-11-15 | PXD027246 | Pride
Project description:marine sponge and seawater metagenomes
Project description:Laparoscopic surgery of the distal colon and rectum requires surgery with an appropriate field of view. A commonly used technique to create a clear exposure is the steep Trendelenburg position in which the patient is positioned in an angle of 15 to 40 degrees with the head down using the effect of gravity to retract the small intestine. This method is associated with haemostatic changes caused by the cranial shift of abdominal organs and blood. Recently, a cellulose compressed sponge was developed as intraoperative retractor, with the aim to keep the small intestines aside while the patient remains in a horizontal position. The safety of the sponge is secured with CE marking. The retractor sponge ensures a clear surgical field and potentially prevents haemostatic instability by avoiding Trendelenburg position. A pilot study in the St Antonius Hospital Nieuwegein has shown that use of the sponge might be associated with shorter hospital stay.