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BioRxiv : the Preprint Server For... Nov 2023Cnidarians have become valuable models for understanding many aspects of developmental biology including the evolution of body plan diversity, novel cell type...
UNLABELLED
Cnidarians have become valuable models for understanding many aspects of developmental biology including the evolution of body plan diversity, novel cell type specification, and regeneration. Most of our understanding of gene function during early development in cnidarians comes from a small number of experimental systems including the sea anemone, . Few molecular tools have been developed for use in hard corals, limiting our understanding of this diverse and ecologically important clade. Here, we report the development of a suite of tools for manipulating and analyzing gene expression during early development in the northern star coral, . We present methods for gene knockdown using short hairpin RNAs, gene overexpression using exogenous mRNAs, and endogenous gene tagging using CRISPR-mediated gene knock-in. Combined with our ability to control spawning in the laboratory, these tools make a tractable experimental system for investigative studies of coral development. Further application of these tools will enable functional analyses of embryonic patterning and morphogenesis across Anthozoa and open new frontiers in coral biology research.
SUMMARY STATEMENT
This study reports the development of the first transgenic knock-in coral, providing the opportunity to track the behavior of various cell types during early coral development.
PubMed: 38948709
DOI: 10.1101/2023.11.16.567385 -
Science Advances Jun 2024Spatial and temporal patterns of future coral bleaching are uncertain, hampering global conservation efforts to protect coral reefs against climate change. Our analysis...
Spatial and temporal patterns of future coral bleaching are uncertain, hampering global conservation efforts to protect coral reefs against climate change. Our analysis of daily projections of ocean warming establishes the severity, annual duration, and onset of severe bleaching risk for global coral reefs this century, pinpointing vital climatic refugia. We show that low-latitude coral regions are most vulnerable to thermal stress and will experience little reprieve from climate mitigation. By 2080, coral bleaching is likely to start on most reefs in spring, rather than late summer, with year-round bleaching risk anticipated to be high for some low-latitude reefs regardless of global efforts to mitigate harmful greenhouse gasses. By identifying Earth's reef regions that are at lowest risk of accelerated bleaching, our results will prioritize efforts to limit future loss of coral reef biodiversity.
Topics: Coral Reefs; Climate Change; Animals; Anthozoa; Coral Bleaching; Conservation of Natural Resources; Biodiversity; Global Warming
PubMed: 38924396
DOI: 10.1126/sciadv.adn9660 -
PloS One 2024The effects of turbidity and sedimentation stress on early life stages of corals are poorly understood, particularly in Atlantic species. Dredging operations, beach...
The effects of turbidity and sedimentation stress on early life stages of corals are poorly understood, particularly in Atlantic species. Dredging operations, beach nourishment, and other coastal construction activities can increase sedimentation and turbidity in nearby coral reef habitats and have the potential to negatively affect coral larval development and metamorphosis, reducing sexual reproduction success. In this study, we investigated the performance of larvae of the threatened Caribbean coral species Orbicella faveolata exposed to suspended sediments collected from a reef site in southeast Florida recently impacted by dredging (Port of Miami), and compared it to the performance of larvae exposed to sediments collected from the offshore, natal reef of the parent colonies. In a laboratory experiment, we tested whether low and high doses of each of these sediment types affected the survival, settlement, and respiration of coral larvae compared to a no-sediment control treatment. In addition, we analyzed the sediments used in the experiments with 16S rRNA gene amplicon sequencing to assess differences in the microbial communities present in the Port versus Reef sediments, and their potential impact on coral performance. Overall, only O. faveolata larvae exposed to the high-dose Port sediment treatment had significantly lower survival rates compared to the control treatment, suggesting an initial tolerance to elevated suspended sediments. However, significantly lower settlement rates were observed in both Port treatments (low- and high-dose) compared to the control treatment one week after exposure, suggesting strong latent effects. Sediments collected near the Port also contained different microbial communities than Reef sediments, and higher relative abundances of the bacteria Desulfobacterales, which has been associated with coral disease. We hypothesize that differences in microbial communities between the two sediments may be a contributing factor in explaining the observed differences in larval performance. Together, these results suggest that the settlement success and survival of O. faveolata larvae are more readily compromised by encountering port inlet sediments compared to reef sediments, with potentially important consequences for the recruitment success of this species in affected areas.
Topics: Animals; Anthozoa; Larva; Geologic Sediments; Coral Reefs; Endangered Species; RNA, Ribosomal, 16S; Florida; Microbiota
PubMed: 38923956
DOI: 10.1371/journal.pone.0292474 -
Marine Drugs Jun 2024A marine-derived fungal strain, sp. ITBBc1, was isolated from coral collected from the South China Sea in Hainan province. Intensive chemical investigation of the...
A marine-derived fungal strain, sp. ITBBc1, was isolated from coral collected from the South China Sea in Hainan province. Intensive chemical investigation of the fermentation extract of this strain afforded four new secondary metabolites (-), named megastigmanones A-C and prenylterphenyllin H, along with four known compounds (-). Their structures were elucidated by extensive spectroscopic analysis including one-and two-dimensional (1D and 2D) NMR spectroscopy and high-resolution electrospray ionization mass spectrometry (HR-ESI-MS). The modified Mosher's method was undertaken to determine the absolute configurations of new compounds. The phytotoxic activity test showed that compounds - exhibited significant antagonistic activity against the germination of L. and L. seeds with a dose-dependent relationship.
Topics: Aspergillus; Anthozoa; Animals; Triticum; Oryza; Secondary Metabolism; Magnetic Resonance Spectroscopy; Seeds; China; Germination; Molecular Structure
PubMed: 38921581
DOI: 10.3390/md22060270 -
PloS One 2024Geochemical proxies of sea surface temperature (SST) and seawater pH (pHsw) in scleractinian coral skeletons are valuable tools for reconstructing tropical climate...
Geochemical proxies of sea surface temperature (SST) and seawater pH (pHsw) in scleractinian coral skeletons are valuable tools for reconstructing tropical climate variability. However, most coral skeletal SST and pHsw proxies are univariate methods that are limited in their capacity to circumvent non-climate-related variability. Here we present a novel multivariate method for reconstructing SST and pHsw from the geochemistry of coral skeletons. Our Scleractinian Multivariate Isotope and Trace Element (SMITE) method optimizes reconstruction skill by leveraging the covariance across an array of coral elemental and isotopic data with SST and pHsw. First, using a synthetic proxy experiment, we find that SMITE SST reconstruction statistics (correlation, accuracy, and precision) are insensitive to noise and variable calibration period lengths relative to Sr/Ca. While SMITE pHsw reconstruction statistics remain relative to δ11B throughout the same synthetic experiment, the magnitude of the long-term trend in pHsw is progressively lost under conditions of moderate-to-high analytical uncertainty. Next, we apply the SMITE method to an array of seven coral-based geochemical variables (B/Ca, δ11B, Li/Ca, Mg/Ca, Sr/Ca, U/Ca & Li/Mg) measured from two Bermudan Porites astreoides corals. Despite a <3.5 year calibration period, SMITE SST and pHsw estimates exhibit significantly better accuracy, precision, and correlation with their respective climate targets than the best single- and dual-proxy estimators. Furthermore, SMITE model parameters are highly reproducible between the two coral cores, indicating great potential for fossil applications (when preservation is high). The results shown here indicate that the SMITE method can outperform the most common coral-based SST and pHsw reconstructions methods to date, particularly in datasets with a large variety of geochemical variables. We therefore provide a list of recommendations and procedures for users to begin implementing the SMITE method as well as an open-source software package to facilitate dissemination of the SMITE method.
Topics: Seawater; Hydrogen-Ion Concentration; Anthozoa; Animals; Temperature; Trace Elements
PubMed: 38917168
DOI: 10.1371/journal.pone.0305607 -
Scientific Reports Jun 2024The application of beneficial microorganisms for corals (BMC) decreases the bleaching susceptibility and mortality rate of corals. BMC selection is typically performed...
The application of beneficial microorganisms for corals (BMC) decreases the bleaching susceptibility and mortality rate of corals. BMC selection is typically performed via molecular and biochemical assays, followed by genomic screening for BMC traits. Herein, we present a comprehensive in silico framework to explore a set of six putative BMC strains. We extracted high-quality DNA from coral samples collected from the Red Sea and performed PacBio sequencing. We identified BMC traits and mechanisms associated with each strain as well as proposed new traits and mechanisms, such as chemotaxis and the presence of phages and bioactive secondary metabolites. The presence of prophages in two of the six studied BMC strains suggests their possible distribution within beneficial bacteria. We also detected various secondary metabolites, such as terpenes, ectoines, lanthipeptides, and lasso peptides. These metabolites possess antimicrobial, antifungal, antiviral, anti-inflammatory, and antioxidant activities and play key roles in coral health by reducing the effects of heat stress, high salinity, reactive oxygen species, and radiation. Corals are currently facing unprecedented challenges, and our revised framework can help select more efficient BMC for use in studies on coral microbiome rehabilitation, coral resilience, and coral restoration.
Topics: Anthozoa; Animals; Indian Ocean; Probiotics; Genomics; Bacteria; Microbiota
PubMed: 38914624
DOI: 10.1038/s41598-024-65152-8 -
Neural Development Jun 2024The complex morphology of neurons requires precise control of their microtubule cytoskeleton. This is achieved by microtubule-associated proteins (MAPs) that regulate...
The complex morphology of neurons requires precise control of their microtubule cytoskeleton. This is achieved by microtubule-associated proteins (MAPs) that regulate the assembly and stability of microtubules, and transport of molecules and vesicles along them. While many of these MAPs function in all cells, some are specifically or predominantly involved in regulating microtubules in neurons. Here we use the sea anemone Nematostella vectensis as a model organism to provide new insights into the early evolution of neural microtubule regulation. As a cnidarian, Nematostella belongs to an outgroup to all bilaterians and thus occupies an informative phylogenetic position for reconstructing the evolution of nervous system development. We identified an ortholog of the microtubule-binding protein doublecortin-like kinase (NvDclk1) as a gene that is predominantly expressed in neurons and cnidocytes (stinging cells), two classes of cells belonging to the neural lineage in cnidarians. A transgenic NvDclk1 reporter line revealed an elaborate network of neurite-like processes emerging from cnidocytes in the tentacles and the body column. A transgene expressing NvDclk1 under the control of the NvDclk1 promoter suggests that NvDclk1 localizes to microtubules and therefore likely functions as a microtubule-binding protein. Further, we generated a mutant for NvDclk1 using CRISPR/Cas9 and show that the mutants fail to generate mature cnidocytes. Our results support the hypothesis that the elaboration of programs for microtubule regulation occurred early in the evolution of nervous systems.
Topics: Animals; Sea Anemones; Neurons; Doublecortin-Like Kinases; Protein Serine-Threonine Kinases; Microtubules; Neurogenesis; Animals, Genetically Modified; Microtubule-Associated Proteins
PubMed: 38909268
DOI: 10.1186/s13064-024-00188-0 -
Molecules (Basel, Switzerland) May 2024Kallopterolides A-I (-), a family of nine diterpenoids possessing either a cleaved pseudopterane or a severed cembrane skeleton, along with several known compounds were...
Kallopterolides A-I (-), a family of nine diterpenoids possessing either a cleaved pseudopterane or a severed cembrane skeleton, along with several known compounds were isolated from the Caribbean Sea plume . The structures and relative configurations of - were characterized by analysis of HR-MS, IR, UV, and NMR spectroscopic data in addition to computational methods and side-by-side comparisons with published NMR data of related congeners. An investigation was conducted as to the potential of the kallopterolides as plausible in vitro anti-inflammatory, antiprotozoal, and antituberculosis agents.
Topics: Diterpenes; Animals; Anthozoa; Antiprotozoal Agents; Caribbean Region; Molecular Structure; Anti-Inflammatory Agents; Magnetic Resonance Spectroscopy; Antitubercular Agents
PubMed: 38893370
DOI: 10.3390/molecules29112493 -
Scientific Reports Jun 2024The mucus surface layer serves vital functions for scleractinian corals and consists mainly of carbohydrates. Its carbohydrate composition has been suggested to be...
The mucus surface layer serves vital functions for scleractinian corals and consists mainly of carbohydrates. Its carbohydrate composition has been suggested to be influenced by environmental conditions (e.g., temperature, nutrients) and microbial pressures (e.g., microbial degradation, microbial coral symbionts), yet to what extend the coral mucus composition is determined by phylogeny remains to be tested. To investigate the variation of mucus carbohydrate compositions among coral species, we analyzed the composition of mucosal carbohydrate building blocks (i.e., monosaccharides) for five species of scleractinian corals, supplemented with previously reported data, to discern overall patterns using cluster analysis. Monosaccharide composition from a total of 23 species (belonging to 14 genera and 11 families) revealed significant differences between two phylogenetic clades that diverged early in the evolutionary history of scleractinian corals (i.e., complex and robust; p = 0.001, R = 0.20), mainly driven by the absence of arabinose in the robust clade. Despite considerable differences in environmental conditions and sample analysis protocols applied, coral phylogeny significantly correlated with monosaccharide composition (Mantel test: p < 0.001, R = 0.70). These results suggest that coral mucus carbohydrates display phylogenetic dependence and support their essential role in the functioning of corals.
Topics: Anthozoa; Animals; Phylogeny; Mucus; Carbohydrates; Monosaccharides
PubMed: 38890484
DOI: 10.1038/s41598-024-64828-5 -
Metabolomics : Official Journal of the... Jun 2024The coral holobiont is underpinned by complex metabolic exchanges between different symbiotic partners, which are impacted by environmental stressors. The chemical...
The coral holobiont is underpinned by complex metabolic exchanges between different symbiotic partners, which are impacted by environmental stressors. The chemical diversity of the compounds produced by the holobiont is high and includes primary and secondary metabolites, as well as volatiles. However, metabolites and volatiles have only been characterised in isolation so far. Here, we applied a paired metabolomic-volatilomic approach to characterise holistically the chemical response of the holobiont under stress. Montipora mollis fragments were subjected to high-light stress (8-fold higher than the controls) for 30 min. Photosystem II (PSII) photochemical efficiency values were 7-fold higher in control versus treatment corals immediately following high-light exposure, but returned to pre-stress levels after 30 min of recovery. Under high-light stress, we identified an increase in carbohydrates (> 5-fold increase in arabinose and fructose) and saturated fatty acids (7-fold increase in myristic and oleic acid), together with a decrease in fatty acid derivatives in both metabolites and volatiles (e.g., 80% decrease in oleamide and nonanal), and other antioxidants (~ 85% decrease in sorbitol and galactitol). These changes suggest short-term light stress induces oxidative stress. Correlation analysis between volatiles and metabolites identified positive links between sorbitol, galactitol, six other metabolites and 11 volatiles, with four of these compounds previously identified as antioxidants. This suggests that these 19 compounds may be related and share similar functions. Taken together, our findings demonstrate how paired metabolomics-volatilomics may illuminate broader metabolic shifts occurring under stress and identify linkages between uncharacterised compounds to putatively determine their functions.
Topics: Animals; Anthozoa; Metabolomics; Light; Stress, Physiological; Volatile Organic Compounds; Photosystem II Protein Complex
PubMed: 38886248
DOI: 10.1007/s11306-024-02136-9