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Marine Drugs May 2024Octocoral of the genus is a kind of marine invertebrate possessing abundant cytotoxic secondary metabolites, such as prostanoids and dolabellanes. In our continuous...
Octocoral of the genus is a kind of marine invertebrate possessing abundant cytotoxic secondary metabolites, such as prostanoids and dolabellanes. In our continuous natural product study of spp., two previously undescribed prostanoids [clavulone I-15-one () and 12--deacetylclavulone I ()] and eleven known analogs (-) were identified. The structures of these new compounds were elucidated based on analysis of their 1D and 2D NMR, HRESIMS, and IR data. Additionally, all tested prostanoids ( and -) showed potent cytotoxic activities against the human oral cancer cell line (Ca9-22). The major compound showed cytotoxic activity against the Ca9-22 cells with the IC value of 2.11 ± 0.03 μg/mL, which echoes the cytotoxic effect of the coral extract. In addition, in silico tools were used to predict the possible effects of isolated compounds on human tumor cell lines and nitric oxide production, as well as the pharmacological potentials.
Topics: Humans; Anthozoa; Animals; Cell Line, Tumor; Prostaglandins; Antineoplastic Agents; Nitric Oxide; Inhibitory Concentration 50; Aquatic Organisms; Molecular Structure
PubMed: 38786610
DOI: 10.3390/md22050219 -
Marine Drugs Apr 2024Marine symbiotic and epiphyte microorganisms are sources of bioactive or structurally novel natural products. Metabolic blockade-based genome mining has been proven to...
Metabolic Blockade-Based Genome Mining of Sea Anemone-Associated sp. S1502 Identifies Atypical Angucyclines WS-5995 A-E: Isolation, Identification, Biosynthetic Investigation, and Bioactivities.
Marine symbiotic and epiphyte microorganisms are sources of bioactive or structurally novel natural products. Metabolic blockade-based genome mining has been proven to be an effective strategy to accelerate the discovery of natural products from both terrestrial and marine microorganisms. Here, the metabolic blockade-based genome mining strategy was applied to the discovery of other metabolites in a sea anemone-associated sp. S1502. We constructed a mutant sp. S1502/Δ that switched to producing the atypical angucyclines WS-5995 A-E, among which WS-5995 E is a new compound. A biosynthetic gene cluster () of the angucyclines was identified through gene knock-out and heterologous expression studies. The biosynthetic pathways of WS-5995 A-E were proposed, the roles of some tailoring and regulatory genes were investigated, and the biological activities of WS-5995 A-E were evaluated. WS-5995 A has significant anti- activity with an IC value of 2.21 μM. The production of antibacterial streptopyrroles and anticoccidial WS-5995 A-E may play a protective role in the mutual relationship between sp. S1502 and its host.
Topics: Streptomyces; Animals; Sea Anemones; Multigene Family; Anti-Bacterial Agents; Biosynthetic Pathways; Genome, Bacterial; Biological Products; Anthraquinones; Angucyclines and Angucyclinones
PubMed: 38786587
DOI: 10.3390/md22050195 -
PeerJ 2024Antibiotics are commonly used for controlling microbial growth in diseased organisms. However, antibiotic treatments during early developmental stages can have negative...
BACKGROUND
Antibiotics are commonly used for controlling microbial growth in diseased organisms. However, antibiotic treatments during early developmental stages can have negative impacts on development and physiology that could offset the positive effects of reducing or eliminating pathogens. Similarly, antibiotics can shift the microbial community due to differential effectiveness on resistant and susceptible bacteria. Though antibiotic application does not typically result in mortality of marine invertebrates, little is known about the developmental and transcriptional effects. These sublethal effects could reduce the fitness of the host organism and lead to negative changes after removal of the antibiotics. Here, we quantify the impact of antibiotic treatment on development, gene expression, and the culturable bacterial community of a model cnidarian, .
METHODS
Ampicillin, streptomycin, rifampicin, and neomycin were compared individually at two concentrations, 50 and 200 µg mL, and in combination at 50 µg mL each, to assess their impact on . First, we determined the impact antibiotics have on larval development. Next Amplicon 16S rDNA gene sequencing was used to compare the culturable bacteria that persist after antibiotic treatment to determine how these treatments may differentially select against the native microbiome. Lastly, we determined how acute (3-day) and chronic (8-day) antibiotic treatments impact gene expression of adult anemones.
RESULTS
Under most exposures, the time of larval settlement extended as the concentration of antibiotics increased and had the longest delay of 3 days in the combination treatment. Culturable bacteria persisted through a majority of exposures where we identified 359 amplicon sequence variants (ASVs). The largest proportion of bacteria belonged to Gammaproteobacteria, and the most common ASVs were identified as and . The acute antibiotic exposure resulted in differential expression of genes related to epigenetic mechanisms and neural processes, while constant application resulted in upregulation of chaperones and downregulation of mitochondrial genes when compared to controls. Gene Ontology analyses identified overall depletion of terms related to development and metabolism in both antibiotic treatments.
DISCUSSION
Antibiotics resulted in a significant increase to settlement time of larvae. Culturable bacterial species after antibiotic treatments were taxonomically diverse. Additionally, the transcriptional effects of antibiotics, and after their removal result in significant differences in gene expression that may impact the physiology of the anemone, which may include removal of bacterial signaling on anemone gene expression. Our research suggests that impacts of antibiotics beyond the reduction of bacteria may be important to consider when they are applied to aquatic invertebrates including reef building corals.
Topics: Animals; Anti-Bacterial Agents; Sea Anemones; Larva; Ampicillin; Neomycin; Streptomycin; Rifampin; Gene Expression
PubMed: 38784394
DOI: 10.7717/peerj.17349 -
Scientific Reports May 2024The chemical and isotopic composition of stony coral skeletons form an important archive of past climate. However, these reconstructions are largely based on empirical...
The chemical and isotopic composition of stony coral skeletons form an important archive of past climate. However, these reconstructions are largely based on empirical relationships often complicated by "vital effects" arising from uncertain physiological processes of the coral holobiont. The skeletons of deep-sea corals, such as Desmophyllum dianthus, are characterised by micron-scale or larger geochemical heterogeneity associated with: (1) centres of calcification (COCs) where nucleation of new skeleton begins, and (2) fibres that thicken the skeleton. These features are difficult to sample cleanly using traditional techniques, resulting in uncertainty surrounding both the causes of geochemical differences and their influence on environmental signals. Here we combine optical, and in-situ chemical and isotopic, imaging tools across a range of spatial resolutions (~ 100 nm to 10 s of μm) in a correlative multimodal imaging (CMI) approach to isolate the microstructural geochemistry of each component. This reveals COCs are characterised by higher organic content, Mg, Li and Sr and lower U, B and δB compared to fibres, reflecting the contrasting biomineralisation mechanisms employed to construct each feature. CMI is rarely applied in Environmental/Earth Sciences, but here we illustrate the power of this approach to unpick the "vital effects" in D. dianthus, and by extension, other scleractinian corals.
Topics: Anthozoa; Animals; Calcification, Physiologic; Biomineralization
PubMed: 38750108
DOI: 10.1038/s41598-024-61772-2 -
Ecology and Evolution May 2024Numerous genomic methods developed over the past two decades have enabled the discovery and extraction of orthologous loci to help resolve phylogenetic relationships...
Numerous genomic methods developed over the past two decades have enabled the discovery and extraction of orthologous loci to help resolve phylogenetic relationships across various taxa and scales. Genome skimming (or low-coverage genome sequencing) is a promising method to not only extract high-copy loci but also 100s to 1000s of phylogenetically informative nuclear loci (e.g., ultraconserved elements [UCEs] and exons) from contemporary and museum samples. The subphylum Anthozoa, including important ecosystem engineers (e.g., stony corals, black corals, anemones, and octocorals) in the marine environment, is in critical need of phylogenetic resolution and thus might benefit from a genome-skimming approach. We conducted genome skimming on 242 anthozoan corals collected from 1886 to 2022. Using existing target-capture baitsets, we bioinformatically obtained UCEs and exons from the genome-skimming data and incorporated them with data from previously published target-capture studies. The mean number of UCE and exon loci extracted from the genome skimming data was 1837 ± 662 SD for octocorals and 1379 ± 476 SD loci for hexacorals. Phylogenetic relationships were well resolved within each class. A mean of 1422 ± 720 loci was obtained from the historical specimens, with 1253 loci recovered from the oldest specimen collected in 1886. We also obtained partial to whole mitogenomes and nuclear rRNA genes from >95% of samples. Bioinformatically pulling UCEs, exons, mitochondrial genomes, and nuclear rRNA genes from genome skimming data is a viable and low-cost option for phylogenetic studies. This approach can be used to review and support taxonomic revisions and reconstruct evolutionary histories, including historical museum and type specimens.
PubMed: 38746545
DOI: 10.1002/ece3.11254 -
ELife May 2024The circadian clock enables anticipation of the day/night cycle in animals ranging from cnidarians to mammals. Circadian rhythms are generated through a...
The circadian clock enables anticipation of the day/night cycle in animals ranging from cnidarians to mammals. Circadian rhythms are generated through a transcription-translation feedback loop (TTFL or pacemaker) with CLOCK as a conserved positive factor in animals. However, CLOCK's functional evolutionary origin and mechanism of action in basal animals are unknown. In the cnidarian , pacemaker gene transcript levels, including (the ortholog), appear arrhythmic under constant darkness, questioning the role of NvCLK. Utilizing CRISPR/Cas9, we generated a allele mutant (), revealing circadian behavior loss under constant dark (DD) or light (LL), while maintaining a 24 hr rhythm under light-dark condition (LD). Transcriptomics analysis revealed distinct rhythmic genes in wild-type (WT) polypsunder LD compared to DD conditions. In LD, polyps exhibited comparable numbers of rhythmic genes, but were reduced in DD. Furthermore, under LD, the polyps showed alterations in temporal pacemaker gene expression, impacting their potential interactions. Additionally, differential expression of non-rhythmic genes associated with cell division and neuronal differentiation was observed. These findings revealed that a light-responsive pathway can partially compensate for circadian clock disruption, and that the gene has evolved in cnidarians to synchronize rhythmic physiology and behavior with the diel rhythm of the earth's biosphere.
Topics: Animals; Circadian Rhythm; Circadian Clocks; Sea Anemones; CLOCK Proteins; Photoperiod; Cnidaria
PubMed: 38743049
DOI: 10.7554/eLife.89499 -
The ISME Journal Jan 2024Temperate phages can interact with bacterial hosts through lytic and lysogenic cycles via different mechanisms. Lysogeny has been identified as the major form of...
Temperate phages can interact with bacterial hosts through lytic and lysogenic cycles via different mechanisms. Lysogeny has been identified as the major form of bacteria-phage interaction in the coral-associated microbiome. However, the lysogenic-to-lytic switch of temperate phages in ecologically important coral-associated bacteria and its ecological impact have not been extensively investigated. By studying the prophages in coral-associated Halomonas meridiana, we found that two prophages, Phm1 and Phm3, are inducible by the DNA-damaging agent mitomycin C and that Phm3 is spontaneously activated under normal cultivation conditions. Furthermore, Phm3 undergoes an atypical lytic pathway that can amplify and package adjacent host DNA, potentially resulting in lateral transduction. The induction of Phm3 triggered a process of cell lysis accompanied by the formation of outer membrane vesicles (OMVs) and Phm3 attached to OMVs. This unique cell-lysis process was controlled by a four-gene lytic module within Phm3. Further analysis of the Tara Ocean dataset revealed that Phm3 represents a new group of temperate phages that are widely distributed and transcriptionally active in the ocean. Therefore, the combination of lateral transduction mediated by temperate phages and OMV transmission offers a versatile strategy for host-phage coevolution in marine ecosystems.
Topics: Halomonas; Anthozoa; Prophages; Animals; Lysogeny; Transduction, Genetic; Mitomycin
PubMed: 38739683
DOI: 10.1093/ismejo/wrae085 -
ELife May 2024Neuropeptides are ancient signaling molecules in animals but only few peptide receptors are known outside bilaterians. Cnidarians possess a large number of G...
Neuropeptides are ancient signaling molecules in animals but only few peptide receptors are known outside bilaterians. Cnidarians possess a large number of G protein-coupled receptors (GPCRs) - the most common receptors of bilaterian neuropeptides - but most of these remain orphan with no known ligands. We searched for neuropeptides in the sea anemone and created a library of 64 peptides derived from 33 precursors. In a large-scale pharmacological screen with these peptides and 161 GPCRs, we identified 31 receptors specifically activated by 1 to 3 of 14 peptides. Mapping GPCR and neuropeptide expression to single-cell sequencing data revealed how cnidarian tissues are extensively connected by multilayer peptidergic networks. Phylogenetic analysis identified no direct orthology to bilaterian peptidergic systems and supports the independent expansion of neuropeptide signaling in cnidarians from a few ancestral peptide-receptor pairs.
Topics: Animals; Sea Anemones; Neuropeptides; Receptors, G-Protein-Coupled; Phylogeny; Signal Transduction
PubMed: 38727714
DOI: 10.7554/eLife.90674 -
ELife May 2024Studies of the starlet sea anemone provide important insights into the early evolution of the circadian clock in animals.
Studies of the starlet sea anemone provide important insights into the early evolution of the circadian clock in animals.
Topics: Animals; Biological Evolution; Circadian Clocks; Circadian Rhythm; Cnidaria; Sea Anemones
PubMed: 38716806
DOI: 10.7554/eLife.98512 -
Science Advances May 2024Many Caribbean coral reefs are near collapse due to various threats. An emerging threat, stony coral tissue loss disease (SCTLD), is spreading across the Western...
Many Caribbean coral reefs are near collapse due to various threats. An emerging threat, stony coral tissue loss disease (SCTLD), is spreading across the Western Atlantic and Caribbean. Data from the U.S. Virgin Islands reveal how SCTLD spread has reduced the abundance of susceptible coral and crustose coralline algae and increased cyanobacteria, fire coral, and macroalgae. A Caribbean-wide structural equation model demonstrates versatility in reef fish and associations with rugosity independent of live coral. Model projections suggest that some reef fishes will decline due to SCTLD, with the largest changes on reefs that lose the most susceptible corals and rugosity. Mapping these projected declines in space indicates how the indirect effects of SCTLD range from undetectable to devastating.
Topics: Animals; Coral Reefs; Anthozoa; Caribbean Region; Fishes; Ecosystem
PubMed: 38701216
DOI: 10.1126/sciadv.adk6808