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Proceedings. Biological Sciences Mar 2013Over the last decade, significant advances have been made in characterization of the coral microbiota. Shifts in its composition often correlate with the appearance of... (Review)
Review
Over the last decade, significant advances have been made in characterization of the coral microbiota. Shifts in its composition often correlate with the appearance of signs of diseases and/or bleaching, thus suggesting a link between microbes, coral health and stability of reef ecosystems. The understanding of interactions in coral-associated microbiota is informed by the on-going characterization of other microbiomes, which suggest that metabolic pathways and functional capabilities define the 'core' microbiota more accurately than the taxonomic diversity of its members. Consistent with this hypothesis, there does not appear to be a consensus on the specificity in the interactions of corals with microbial commensals, even though recent studies report potentially beneficial functions of the coral-associated bacteria. They cycle sulphur, fix nitrogen, produce antimicrobial compounds, inhibit cell-to-cell signalling and disrupt virulence in opportunistic pathogens. While their beneficial functions have been documented, it is not certain whether or how these microbes are selected by the hosts. Therefore, understanding the role of innate immunity, signal and nutrient exchange in the establishment of coral microbiota and in controlling its functions will probably reveal ancient, evolutionarily conserved mechanisms that dictate the outcomes of host-microbial interactions, and impact the resilience of the host.
Topics: Animals; Anthozoa; Bacterial Physiological Phenomena; Coral Reefs; Dinoflagellida; Symbiosis
PubMed: 23363627
DOI: 10.1098/rspb.2012.2328 -
The ISME Journal Feb 2020Reef-building corals harbour an astonishing diversity of microorganisms, including endosymbiotic microalgae, bacteria, archaea, and fungi. The metabolic interactions... (Review)
Review
Reef-building corals harbour an astonishing diversity of microorganisms, including endosymbiotic microalgae, bacteria, archaea, and fungi. The metabolic interactions within this symbiotic consortium are fundamental to the ecological success of corals and the unique productivity of coral reef ecosystems. Over the last two decades, scientific efforts have been primarily channelled into dissecting the symbioses occurring in coral tissues. Although easily accessible, this compartment is only 2-3 mm thick, whereas the underlying calcium carbonate skeleton occupies the vast internal volume of corals. Far from being devoid of life, the skeleton harbours a wide array of algae, endolithic fungi, heterotrophic bacteria, and other boring eukaryotes, often forming distinct bands visible to the bare eye. Some of the critical functions of these endolithic microorganisms in coral health, such as nutrient cycling and metabolite transfer, which could enable the survival of corals during thermal stress, have long been demonstrated. In addition, some of these microorganisms can dissolve calcium carbonate, weakening the coral skeleton and therefore may play a major role in reef erosion. Yet, experimental data are wanting due to methodological limitations. Recent technological and conceptual advances now allow us to tease apart the complex physical, ecological, and chemical interactions at the heart of coral endolithic microbial communities. These new capabilities have resulted in an excellent body of research and provide an exciting outlook to further address the functional microbial ecology of the "overlooked" coral skeleton.
Topics: Animals; Anthozoa; Archaea; Bacteria; Coral Reefs; Fungi; Microalgae; Microbiota; Symbiosis
PubMed: 31690886
DOI: 10.1038/s41396-019-0548-z -
Microbial Biotechnology Mar 2009
Topics: Animals; Anthozoa; Bacteria; Seawater
PubMed: 21261903
DOI: 10.1111/j.1751-7915.2009.00090_15.x -
Cell Structure and Function Oct 2002Green fluorescent protein (GFP) from the bioluminescent jellyfish Aequorea victoria has become an important tool in molecular and cellular biology as a transcriptional... (Review)
Review
Green fluorescent protein (GFP) from the bioluminescent jellyfish Aequorea victoria has become an important tool in molecular and cellular biology as a transcriptional reporter, fusion tag, and biosensor. Most significantly, it encodes a chromophore intrinsically within its protein sequence, obviating the need for external substrates or cofactors and enabling the genetic encoding of strong fluorescence. Mutagenesis studies have generated GFP variants with new colors, improved fluorescence and other biochemical properties. In parallel, GFPs and GFP-like molecules have been cloned from other organisms, including the bioluminescent sea pansy Renilla reniformis and other non-bioluminescent Anthozoa animals. In the jellyfish and sea pansy, the GFPs are coupled to their chemoluminescence. Instead of emitting the blue light generated by aequorin and luciferase, the GFPs absorb their energy of primary emission and emit green light, which travels farther in the sea. In contrast, GFP-like proteins in reef Anthozoa are thought to play a role in photoprotection of their symbiotic zooxanthellae in shallow water; they transform absorbed UV radiation contained in sunlight into longer fluorescence wavelengths (Salih, A., Larkum, A., Cox, G., Kuhl, M., and Hoegh-Guldberg, O. 2000. Nature, 408: 850-853). In this review, I will describe both the biological and practical aspects of Anthozoan GFP-like proteins, many of which will be greatly improved in utility and commercially available before long. The ubiquity of these molecular tools makes it important to appreciate the interplay between sunlight and GFP-like proteins of Anthozoan animals, and to consider the optimal use of these unique proteins in biological studies.
Topics: Animals; Anthozoa; Eukaryotic Cells; Green Fluorescent Proteins; Luminescent Proteins; Microscopy, Fluorescence; Protein Engineering; Red Fluorescent Protein
PubMed: 12502888
DOI: 10.1247/csf.27.343 -
Scientific Reports Jul 2020Research with coral embryos and larvae often requires laborious manual counting and sorting of individual specimens, usually via microscopy. Because many coral species...
Research with coral embryos and larvae often requires laborious manual counting and sorting of individual specimens, usually via microscopy. Because many coral species spawn only once per year during a narrow temporal window, sample processing is a time-limiting step for research on the early life-history stages of corals. Flow cytometry, an automated technique for measuring and sorting particles, cells, and cell-clusters, is a potential solution to this bottleneck. Yet most flow cytometers do not accommodate live organisms of the size of most coral embryos (> 250 µm), and sample processing is often destructive. Here we tested the ability of a large-particle flow cytometer with a gentle pneumatic sorting mechanism to process and spectrally sort live and preserved Montipora capitata coral embryos and larvae. Average survival rates of mechanically-sorted larvae were over 90% and were comparable to those achieved by careful hand-sorting. Preserved eggs and embryos remained intact throughout the sorting process and were successfully sorted based on real-time size and fluorescence detection. In-line bright-field microscopy images were captured for each sample object as it passed through the flow-cell, enabling the identification of early-stage embryos (2-cell to morula stage). Samples were counted and sorted at an average rate of 4 s larva and as high as 0.2 s larva for high-density samples. Results presented here suggest that large-particle flow cytometry has the potential to significantly increase efficiency and accuracy of data collection and sample processing during time-limited coral spawning events, facilitating larger-scale and higher-replication studies with an expanded number of species.
Topics: Animals; Anthozoa; Flow Cytometry; Larva
PubMed: 32737431
DOI: 10.1038/s41598-020-69491-0 -
Microbiology Spectrum Jun 2023Bleaching is one of the most relevant factors implicated in the integrity of coral reef ecosystems, with the increasing frequency and intensity of damaging events...
Bleaching is one of the most relevant factors implicated in the integrity of coral reef ecosystems, with the increasing frequency and intensity of damaging events representing a serious threat to reef biodiversity. Here, we analyzed changes in coral-associated bacteria from three types of non-bleached and bleached scleractinian corals (Acropora digitifera, Galaxea fascicularis, and Porites pukoensis) in Hainan Luhuitou peninsula coastal areas. The community structure of symbiotic bacteria differed significantly among the three apparently healthy corals. The bleached corals had higher bacterial alpha diversity and some specific bacteria genera, including , , , , , , , , Sva0996 marine group, , and unclassified_c_Gammaproteobacteria, were consistently increased in bleached groups. Network analysis revealed significantly different degrees of modularity between bleached and non-bleached groups at the bacterial genus level, and a higher proportion of links was dominated by positive co-occurrences. Functional prediction analysis illustrated that coral-associated bacteria remained relatively consistent in the bleached and non-bleached groups. Structure equation modeling revealed that the bacterial community diversity and function were directly influenced by host and environment factors. These findings suggested that coral-associated bacterial responses to bleaching occur in a host-dependent manner, informing novel strategies for restoring coral and aiding adaption to bleaching stress. Accumulating evidence indicates that coral-associated bacteria play an important role in the health of holobionts. However, the variability of the symbiotic bacterial community structure among coral species with different coral health statuses remains largely unknown. Here, we investigated three apparent non-bleached (healthy) and bleached coral species (sampled ), involving related symbiotic bacterial profiles, including composition, alpha diversity, network relationship, and potential function. Structural equation modeling analysis was used to analyze the relationship between coral status and abiotic and biotic factors. The bacterial community structure of different groups was shown to exhibit host-specific traits. Both host and environmental impacts had primary effects on coral-associated microbial communities. Future studies are needed to identify the mechanisms that mediate divergent microbial consortia.
Topics: Animals; Anthozoa; Bacteria; Coral Reefs; Microbiota; Gammaproteobacteria
PubMed: 37191552
DOI: 10.1128/spectrum.04910-22 -
Nature Chemical Biology Jun 2022Diterpenes are major defensive small molecules that enable soft corals to survive without a tough exterior skeleton, and, until now, their biosynthetic origin has...
Diterpenes are major defensive small molecules that enable soft corals to survive without a tough exterior skeleton, and, until now, their biosynthetic origin has remained intractable. Furthermore, biomedical application of these molecules has been hampered by lack of supply. Here, we identify and characterize coral-encoded terpene cyclase genes that produce the eunicellane precursor of eleutherobin and cembrene, representative precursors for the >2,500 terpenes found in octocorals. Related genes are found in all sequenced octocorals and form their own clade, indicating a potential ancient origin concomitant with the split between the hard and soft corals. Eleutherobin biosynthetic genes are colocalized in a single chromosomal region. This demonstrates that, like plants and microbes, animals also harbor defensive biosynthetic gene clusters, supporting a recombinational model to explain why specialized or defensive metabolites are adjacently encoded in the genome.
Topics: Animals; Anthozoa; Chromosomes; Genome; Multigene Family; Terpenes
PubMed: 35606556
DOI: 10.1038/s41589-022-01027-1 -
Scientific Reports Feb 2019Corals comprise a biomineralizing cnidarian, dinoflagellate algal symbionts, and associated microbiome of prokaryotes and viruses. Ongoing efforts to conserve coral...
Corals comprise a biomineralizing cnidarian, dinoflagellate algal symbionts, and associated microbiome of prokaryotes and viruses. Ongoing efforts to conserve coral reefs by identifying the major stress response pathways and thereby laying the foundation to select resistant genotypes rely on a robust genomic foundation. Here we generated and analyzed a high quality long-read based ~886 Mbp nuclear genome assembly and transcriptome data from the dominant rice coral, Montipora capitata from Hawai'i. Our work provides insights into the architecture of coral genomes and shows how they differ in size and gene inventory, putatively due to population size variation. We describe a recent example of foreign gene acquisition via a bacterial gene transfer agent and illustrate the major pathways of stress response that can be used to predict regulatory components of the transcriptional networks in M. capitata. These genomic resources provide insights into the adaptive potential of these sessile, long-lived species in both natural and human influenced environments and facilitate functional and population genomic studies aimed at Hawaiian reef restoration and conservation.
Topics: Animals; Anthozoa; Genome; Stress, Physiological; Transcription, Genetic
PubMed: 30796282
DOI: 10.1038/s41598-019-39274-3 -
Current Biology : CB Oct 2022Corals have long been known to generate local fluid flows using ciliary beating, but the importance of these ciliary flows is just being discovered. Two new papers shed...
Corals have long been known to generate local fluid flows using ciliary beating, but the importance of these ciliary flows is just being discovered. Two new papers shed light on how ciliary-flow physics plays a key role in shaping coral physiology.
Topics: Animals; Anthozoa; Coral Reefs
PubMed: 36220095
DOI: 10.1016/j.cub.2022.08.049 -
Proceedings. Biological Sciences Oct 2023Deep-sea lineages are generally thought to arise from shallow-water ancestors, but this hypothesis is based on a relatively small number of taxonomic groups. Anthozoans,...
Deep-sea lineages are generally thought to arise from shallow-water ancestors, but this hypothesis is based on a relatively small number of taxonomic groups. Anthozoans, which include corals and sea anemones, are significant contributors to the faunal diversity of the deep sea, but the timing and mechanisms of their invasion into this biome remain elusive. Here, we reconstruct a fully resolved, time-calibrated phylogeny of 83 species in the order Antipatharia (black coral) to investigate their bathymetric evolutionary history. Our reconstruction indicates that extant black coral lineages first diversified in continental slope depths (∼250-3000 m) during the early Silurian (∼437 millions of years ago (Ma)) and subsequently radiated into, and diversified within, both continental shelf (less than 250 m) and abyssal (greater than 3000 m) habitats. Ancestral state reconstruction analysis suggests that the appearance of morphological features that enhanced the ability of black corals to acquire nutrients coincided with their invasion of novel depths. Our findings have important conservation implications for anthozoan lineages, as the loss of 'source' slope lineages could threaten millions of years of evolutionary history and confound future invasion events, thereby warranting protection.
Topics: Animals; Anthozoa; Ecosystem; Phylogeny; Sea Anemones
PubMed: 37788705
DOI: 10.1098/rspb.2023.1107