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Annual Review of Animal Biosciences Feb 2021The use of Beneficial Microorganisms for Corals (BMCs) has been proposed recently as a tool for the improvement of coral health, with knowledge in this research topic... (Review)
Review
The use of Beneficial Microorganisms for Corals (BMCs) has been proposed recently as a tool for the improvement of coral health, with knowledge in this research topic advancing rapidly. BMCs are defined as consortia of microorganisms that contribute to coral health through mechanisms that include () promoting coral nutrition and growth, () mitigating stress and impacts of toxic compounds, () deterring pathogens, and () benefiting early life-stage development. Here, we review the current proposed BMC approach and outline the studies that have proven its potential to increase coral resilience to stress. We revisit and expand the list of putative beneficial microorganisms associated with corals and their proposed mechanismsthat facilitate improved host performance. Further, we discuss the caveats and bottlenecks affecting the efficacy of BMCs and close by focusing on the next steps to facilitate application at larger scales that can improve outcomes for corals and reefs globally.
Topics: Animals; Anthozoa; Dinoflagellida; Microbiota; Probiotics; Symbiosis
PubMed: 33321044
DOI: 10.1146/annurev-animal-090120-115444 -
Biological Reviews of the Cambridge... May 2018Hydra is emerging as a model organism for studies of ageing in early metazoan animals, but reef corals offer an equally ancient evolutionary perspective as well as... (Review)
Review
Hydra is emerging as a model organism for studies of ageing in early metazoan animals, but reef corals offer an equally ancient evolutionary perspective as well as several advantages, not least being the hard exoskeleton which provides a rich fossil record as well as a record of growth and means of ageing of individual coral polyps. Reef corals are also widely regarded as potentially immortal at the level of the asexual lineage and are assumed not to undergo an intrinsic ageing process. However, putative molecular indicators of ageing have recently been detected in reef corals. While many of the large massive coral species attain considerable ages (>600 years) there are other much shorter-lived species where older members of some populations show catastrophic mortality, compared to juveniles, under environmental stress. Other studies suggestive of ageing include those demonstrating decreased reproduction, increased susceptibility to oxidative stress and disease, reduced regeneration potential and declining growth rate in mature colonies. This review aims to promote interest and research in reef coral ageing, both as a useful model for the early evolution of ageing and as a factor in studies of ecological impacts on reef systems in light of the enhanced effects of environmental stress on ageing in other organisms.
Topics: Aging; Animals; Anthozoa; Biological Evolution; Coral Reefs
PubMed: 29282837
DOI: 10.1111/brv.12391 -
Philosophical Transactions of the Royal... Sep 2020This review explores how microbial symbioses may have influenced and continue to influence the evolution of reef-building corals (Cnidaria; Scleractinia). The coral... (Review)
Review
This review explores how microbial symbioses may have influenced and continue to influence the evolution of reef-building corals (Cnidaria; Scleractinia). The coral holobiont comprises a diverse microbiome including dinoflagellate algae (Dinophyceae; Symbiodiniaceae), bacteria, archaea, fungi and viruses, but here we focus on the Symbiodiniaceae as knowledge of the impact of other microbial symbionts on coral evolution is scant. Symbiosis with Symbiodiniaceae has extended the coral's metabolic capacity through metabolic handoffs and horizontal gene transfer (HGT) and has contributed to the ecological success of these iconic organisms. It necessitated the prior existence or the evolution of a series of adaptations of the host to attract and select the right symbionts, to provide them with a suitable environment and to remove disfunctional symbionts. Signatures of microbial symbiosis in the coral genome include HGT from Symbiodiniaceae and bacteria, gene family expansions, and a broad repertoire of oxidative stress response and innate immunity genes. Symbiosis with Symbiodiniaceae has permitted corals to occupy oligotrophic waters as the algae provide most corals with the majority of their nutrition. However, the coral-Symbiodiniaceae symbiosis is sensitive to climate warming, which disrupts this intimate relationship, causing coral bleaching, mortality and a worldwide decline of coral reefs. This article is part of the theme issue 'The role of the microbiome in host evolution'.
Topics: Animals; Anthozoa; Biological Evolution; Dinoflagellida; Global Warming; Microbiota; Symbiosis
PubMed: 32772672
DOI: 10.1098/rstb.2019.0591 -
Science (New York, N.Y.) Mar 2019
Topics: Adaptation, Physiological; Animals; Anthozoa; Climate Change; Coral Reefs; Environmental Restoration and Remediation; Genetic Engineering; Selective Breeding
PubMed: 30898914
DOI: 10.1126/science.363.6433.1264 -
Trends in Microbiology Aug 2019Coral reefs rely upon the highly optimized coral-Symbiodiniaceae symbiosis, making them sensitive to environmental change and susceptible to anthropogenic stress. Coral... (Review)
Review
Coral reefs rely upon the highly optimized coral-Symbiodiniaceae symbiosis, making them sensitive to environmental change and susceptible to anthropogenic stress. Coral bleaching is predominantly attributed to photo-oxidative stress, yet nutrient availability and metabolism underpin the stability of symbioses. Recent studies link symbiont proliferation under nutrient enrichment to bleaching; however, the interactions between nutrients and symbiotic stability are nuanced. Here, we demonstrate how bleaching is regulated by the forms and ratios of available nutrients and their impacts on autotrophic carbon metabolism, rather than algal symbiont growth. By extension, historical nutrient conditions mediate host-symbiont compatibility and bleaching tolerance over proximate and evolutionary timescales. Renewed investigations into the coral nutrient metabolism will be required to truly elucidate the cellular mechanisms leading to coral bleaching.
Topics: Animals; Anthozoa; Carbon; Dinoflagellida; Microbiota; Nutrients; Phosphorus; Symbiosis; Thermotolerance
PubMed: 30987816
DOI: 10.1016/j.tim.2019.03.004 -
Trends in Microbiology Oct 2020As a result of increased reef degradation, restoration efforts are now being widely applied on coral reefs. However, outplanted coral survival in restoration zones... (Review)
Review
As a result of increased reef degradation, restoration efforts are now being widely applied on coral reefs. However, outplanted coral survival in restoration zones varies substantially, and coral mortality can be a significant limitation to the success of restoration efforts. With reef restoration now occurring within, and adjacent to, nationally preserved and managed marine parks, the potential risks of mortality events and disease spread to adjacent marine populations need to be considered, particularly as these ecosystems continue to decline. We review the causes and consequences of coral mortality and disease outbreaks within the context of coral restoration, highlighting knowledge gaps in our understanding of the restored coral microbiome and discussing management practices for assessing coral disease. We identify the need for research efforts into monitoring and diagnostics of disease within coral restoration, as well as practices to mitigate and manage coral disease risks in restoration.
Topics: Animals; Anthozoa; Bacteria; Bacterial Physiological Phenomena; Conservation of Natural Resources; Coral Reefs; Ecosystem
PubMed: 32739101
DOI: 10.1016/j.tim.2020.06.002 -
Molecular Phylogenetics and Evolution Aug 2021The advent of high throughput sequencing technologies provides an opportunity to resolve phylogenetic relationships among closely related species. By incorporating...
The advent of high throughput sequencing technologies provides an opportunity to resolve phylogenetic relationships among closely related species. By incorporating hundreds to thousands of unlinked loci and single nucleotide polymorphisms (SNPs), phylogenomic analyses have a far greater potential to resolve species boundaries than approaches that rely on only a few markers. Scleractinian taxa have proved challenging to identify using traditional morphological approaches and many groups lack an adequate set of molecular markers to investigate their phylogenies. Here, we examine the potential of Restriction-site Associated DNA sequencing (RADseq) to investigate phylogenetic relationships and species limits within the scleractinian coral genus Porites. A total of 126 colonies were collected from 16 localities in the seas surrounding the Arabian Peninsula and ascribed to 12 nominal and two unknown species based on their morphology. Reference mapping was used to retrieve and compare nearly complete mitochondrial genomes, ribosomal DNA, and histone loci. De novo assembly and reference mapping to the P. lobata coral transcriptome were compared and used to obtain thousands of genome-wide loci and SNPs. A suite of species discovery methods (phylogenetic, ordination, and clustering analyses) and species delimitation approaches (coalescent-based, species tree, and Bayesian Factor delimitation) suggested the presence of eight molecular lineages, one of which included six morphospecies. Our phylogenomic approach provided a fully supported phylogeny of Porites from the Arabian Peninsula, suggesting the power of RADseq data to solve the species delineation problem in this speciose coral genus.
Topics: Animals; Anthozoa; Arabia; Bayes Theorem; DNA, Ribosomal; Genome, Mitochondrial; Phylogeny; Sequence Analysis, DNA
PubMed: 33813021
DOI: 10.1016/j.ympev.2021.107173 -
Science (New York, N.Y.) Sep 2023Genome-wide study in staghorn coral identifies markers of disease resistance.
Genome-wide study in staghorn coral identifies markers of disease resistance.
Topics: Animals; Anthozoa; Coral Reefs; Disease Resistance; Genome-Wide Association Study
PubMed: 37769086
DOI: 10.1126/science.adk2492 -
Scientific Reports Mar 2020Dredging increases suspended sediment concentrations (SSCs), causing elevated water turbidity (cloudiness) and light attenuation. Close to dredging, low light periods...
Dredging increases suspended sediment concentrations (SSCs), causing elevated water turbidity (cloudiness) and light attenuation. Close to dredging, low light periods can extend over many days, affecting phototrophic epibenthic organisms like corals. To improve the ability to predict and manage dredging impacts, we tested the response of corals to an extended period of elevated turbidity using an automated sediment dosing system that precisely controlled SSCs and adjusted light availability accordingly. Replicates of four common species of corals encompassing different morphologies were exposed to turbidity treatments of 0-100 mg L SSC, corresponding to daily light integrals of 12.6 to 0 mol quanta m d, over a period of ∼7 weeks. Symbiotic dinoflagellate density and algal pigment concentration, photosynthetic yields, lipid concentrations and ratios and growth varied among the turbidity treatments, with corals exhibiting photoacclimation within low turbidity treatments. A range of physiological responses were observed within the high turbidity treatments (low light), including bleaching and changes in lipid levels and ratios. Most corals, except P. damicornis, were capable of adjusting to a turbidity treatment involving a mean light level of 2.3 mol photons m d in conjunction with a SSC of 10 mg L over the 7 week period.
Topics: Acclimatization; Animals; Anthozoa; Dinoflagellida; Geologic Sediments; Light; Lipid Metabolism; Photosynthesis; Phototrophic Processes; Symbiosis; Time Factors
PubMed: 32179846
DOI: 10.1038/s41598-020-61712-w -
Molecular Biology and Evolution Aug 2021Corals build the structural foundation of coral reefs, one of the most diverse and productive ecosystems on our planet. Although the process of coral calcification that...
Corals build the structural foundation of coral reefs, one of the most diverse and productive ecosystems on our planet. Although the process of coral calcification that allows corals to build these immense structures has been extensively investigated, we still know little about the evolutionary processes that allowed the soft-bodied ancestor of corals to become the ecosystem builders they are today. Using a combination of phylogenomics, proteomics, and immunohistochemistry, we show that scleractinian corals likely acquired the ability to calcify sometime between ∼308 and ∼265 Ma through a combination of lineage-specific gene duplications and the co-option of existing genes to the calcification process. Our results suggest that coral calcification did not require extensive evolutionary changes, but rather few coral-specific gene duplications and a series of small, gradual optimizations of ancestral proteins and their co-option to the calcification process.
Topics: Animals; Anthozoa; Calcification, Physiologic; Coral Reefs; Ecosystem; Phylogeny
PubMed: 33871620
DOI: 10.1093/molbev/msab103