Project description:<p>Marine sponges can host abundant and diverse microbiomes, which can largely influence the metabolism and other phenotypic traits of the host. However, information on the potential relationships between sponge microbiomes and metabolic signatures, other than secondary metabolites explored for biotechnological purposes, needs further investigation. Applying an integrated approach, we investigated the microbiomes associated with 4 ubiquitous Mediterranean sponge species (i.e., Petrosia ficiformis, Chondrosia reniformis, Crambe crambe and Chondrilla nucula), correlated with their metabolomic patterns (in terms of lipidomics) and microbial predicted functions. Microscopy observations of sponge tissues revealed differences in microbial abundances, which, however, were only partially linked to their diversity assessed through metabarcoding. The microbiomes of the 4 sponges showed a species-specific composition and a different core size, which was independent from the microbial diversity of the surrounding seawater. Predicted functions of the associated microbiomes allowed identifying 2 functional host clusters: one more related to heterotrophic pathways and the other more linked to phototrophic activities. Differences in the microbiomes were also associated with different metabolic profiles, mostly due to specific compounds characterizing the host and its microbiome. Overall, this study provides new insights on the functionality of sponges and their prokaryotic symbioses’, and in particular, it discloses a descriptive sketch of the diverse compartments forming the sponge holobiont.</p>
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:Marine sponges represent one of the few eukaryotic groups that ubiquitously harbor symbiotic members of the Thaumarchaeota, which are important chemoautotrophic ammonia-oxidizers in many environments. However in most studies, direct demonstration of ammonia-oxidation by these archaea within sponges is lacking, and little is known about sponge-specific adaptations of archaeal ammonia oxidizers (AOA). In this study, we characterized the thaumarchaeal symbiont of the marine sponge Ianthella basta using metaproteogenomics, fluorescence in situ hybridization, qPCR and direct isotope-based functional assays. We demonstrate that the I. basta symbiont is not closely related to other genomically sequenced sponge AOA and is a member of a new genus. “Candidatus Nitrosospongia bastadiensis” is an abundant symbiont that is solely responsible for nitrite formation from ammonia in I. basta that surprisingly does not harbor nitrite-oxidizing microbes. Consistently, Ca N. bastadiensis encodes and expresses the genetic repertoire required for chemolithoautotrophic ammonia oxidation. Furthermore, we show that this AOA is equipped with an expanded set of extracellular subtilisin-like proteases, a metalloprotease unique among archaea, as well as a putative branched-chain amino acid ABC transporter. This repertoire is strongly indicative of a mixotrophic lifestyle and is (with slight variations) also found in other sponge-associated, but not in free-living AOA. We predict that this feature as well as an expanded and unique set of secreted serpins (protease inhibitors), a unique array of eukaryotic-like proteins, and a DNA-phosporothioation system likely involved in defense against foreign DNA, represent important adaptations of AOA to life within these ancient filter-feeding animals.
2019-11-13 | PXD012484 | Pride
Project description:Testing DNA and PCR replication for DNA metabarcoding marine macrobenthos
Project description:The mass spec data for PRMPs detected in marine sponges is deposited. Also the data differentiating leucine and isoleucine residues in cyclic peptides is deposited.