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Trends in Ecology & Evolution Mar 2024The photosynthetic symbionts of corals sustain biodiverse reefs in nutrient-poor, tropical waters. Recent genomic data illuminate the evolution of coral symbionts under... (Review)
Review
The photosynthetic symbionts of corals sustain biodiverse reefs in nutrient-poor, tropical waters. Recent genomic data illuminate the evolution of coral symbionts under genome size constraints and suggest that retention of the facultative lifestyle, widespread among these algae, confers a selective advantage when compared with a strict symbiotic existence. We posit that the coral symbiosis is analogous to a 'bioreactor' that selects winner genotypes and allows them to rise to high numbers in a sheltered habitat prior to release by the coral host. Our observations lead to a novel hypothesis, the 'stepping-stone model', which predicts that local adaptation under both the symbiotic and free-living stages, in a stepwise fashion, accelerates coral alga diversity and the origin of endemic strains and species.
Topics: Animals; Anthozoa; Coral Reefs; Dinoflagellida; Ecosystem; Biodiversity; Symbiosis
PubMed: 37953106
DOI: 10.1016/j.tree.2023.10.005 -
PeerJ 2023Anthropogenic stressors threaten reefs worldwide and natural coral reproduction may be inadequate to meet this challenge. Land-based culture can provide increased coral...
Anthropogenic stressors threaten reefs worldwide and natural coral reproduction may be inadequate to meet this challenge. Land-based culture can provide increased coral growth, especially with microfragments. We tested whether culture methods using different algal fouling communities could improve the growth and health metrics of microfragments of the Hawaiian coral, Culture method fouling communities were: (1) similar to a reef environment (Mini Reef); (2) clean tanks managed to promote crustose coralline algae (Clean Start); and (3) tanks curated beforehand with poorly-competing algae (Green Film) assessed in winter and summer months. The Green Film method during the winter produced the fastest microfragment mean growth at 28 days until the first row of new polyps developed, and also the highest tank and plate metric health scores. Time efficient, standardized methods for land-based culture designed to maximize growth and production of coral fragments will contribute considerably to the success of large-scale restoration efforts.
Topics: Animals; Anthozoa; Coral Reefs; Hawaii; Seasons
PubMed: 37576514
DOI: 10.7717/peerj.15723 -
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 -
Proceedings of the National Academy of... Oct 2023Isolation of the Caribbean Sea from the tropical Eastern Pacific by uplift of the Isthmus of Panama in the late Pliocene was associated with major, taxonomically...
Isolation of the Caribbean Sea from the tropical Eastern Pacific by uplift of the Isthmus of Panama in the late Pliocene was associated with major, taxonomically variable, shifts in Caribbean biotic composition, and extinction, but inferred causes of these biological changes have remained elusive. We addressed this through falsifiable hypotheses about how independently determined historical changes in oceanographic conditions may have been responsible. The most striking environmental change was a sharp decline in upwelling intensity as measured from decreases in intra-annual fluctuations in temperature and consequently in planktonic productivity. We then hypothesized three general categories of biological response based upon observed differences in natural history between the oceans today. These include changes in feeding ecology, life histories, and habitats. As expected, suspension feeders and predators became rarer as upwelling declined. However, predicted increases in benthic productivity by reef corals, and benthic algae were drawn out over more than 1 Myr as seagrass and coral reef habitats proliferated; a shift that was itself driven by declining upwelling. Similar time lags occurred for predicted shifts in reproductive life history characteristics of bivalves, gastropods, and bryozoans. Examination of the spatial variability of biotic change helps to understand the time lags. Many older species characteristic of times before environmental conditions had changed tended to hang on in progressively smaller proportions of locations until they became extinct as expected from metapopulation theory and the concept of extinction debt. Faunal turnover may not occur until a million or more years after the environmental changes ultimately responsible.
Topics: Animals; Ecosystem; Caribbean Region; Ecology; Coral Reefs; Anthozoa
PubMed: 37816056
DOI: 10.1073/pnas.2307520120 -
Applied and Environmental Microbiology Oct 2023Microbial interactions contribute significantly to coral health in the marine environment. Most beneficial associations have been described with their bacterial... (Review)
Review
Microbial interactions contribute significantly to coral health in the marine environment. Most beneficial associations have been described with their bacterial communities, but knowledge of beneficial associations between protozoan ciliates and corals is still lacking. Ciliates are important bacterial predators and provide nutrition to higher trophic-level organisms. The mucus secreted by corals and the microenvironment of the coral surface layer attract ciliates based on their food preferences. The mixotrophic and heterotrophic ciliates play a major role in nutrient cycling by increasing nitrogen, phosphorus, and extractable sulfur, which can enhance the proliferation of coral beneficial microbe. Besides, bacterial predator ciliates reduce the pathogenic bacterial population that infects the coral and also act as bioindicators for assessing the toxicity of the reef ecosystem. Thus, these ciliates can be used as a beneficial partner in influencing coral health and resilience under various stress conditions. Herein, we explore the urgent need to understand the complex beneficial interactions of ciliates that may occur in the coral reef ecosystem.
Topics: Animals; Anthozoa; Ecosystem; Coral Reefs; Symbiosis; Microbial Interactions; Bacteria
PubMed: 37702497
DOI: 10.1128/aem.01217-23 -
Scientific Reports Jul 2023Transient receptor potential melastatin 2 (TRPM2) cation channel activity is required for insulin secretion, immune cell activation and body heat control. Channel...
Transient receptor potential melastatin 2 (TRPM2) cation channel activity is required for insulin secretion, immune cell activation and body heat control. Channel activation upon oxidative stress is involved in the pathology of stroke and neurodegenerative disorders. Cytosolic Ca, ADP-ribose (ADPR) and phosphatidylinositol-4,5-bisphosphate (PIP) are the obligate activators of the channel. Several TRPM2 cryo-EM structures have been resolved to date, yet functionality of the purified protein has not been tested. Here we reconstituted overexpressed and purified TRPM2 from Nematostella vectensis (nvTRPM2) into lipid bilayers and found that the protein is fully functional. Consistent with the observations in native membranes, nvTRPM2 in lipid bilayers is co-activated by cytosolic Ca and either ADPR or ADPR-2'-phosphate (ADPRP). The physiological metabolite ADPRP has a higher apparent affinity than ADPR. In lipid bilayers nvTRPM2 displays a large linear unitary conductance, its open probability (P) shows little voltage dependence and is stable over several minutes. P is high without addition of exogenous PIP, but is largely blunted by treatment with poly-L-Lysine, a polycation that masks PIP headgroups. These results indicate that PIP or some other activating phosphoinositol lipid co-purifies with nvTRPM2, suggesting a high PIP binding affinity of nvTRPM2 under physiological conditions.
Topics: Animals; Lipid Bilayers; TRPM Cation Channels; Adenosine Diphosphate Ribose; Cations; Sea Anemones; Calcium
PubMed: 37454209
DOI: 10.1038/s41598-023-38640-6 -
Marine Drugs Aug 2023Marine-derived fungi are renowned as a source of astonishingly significant and synthetically appealing metabolites that are proven as new lead chemicals for chemical,... (Review)
Review
Marine-derived fungi are renowned as a source of astonishingly significant and synthetically appealing metabolites that are proven as new lead chemicals for chemical, pharmaceutical, and agricultural fields. is a saprotrophic, ubiquitous, and halophilic fungus that is commonly found in different marine ecosystems. This fungus can cause aspergillosis in sea fan corals leading to sea fan mortality with subsequent changes in coral community structure. Interestingly, is a prolific source of distinct and structurally varied metabolites such as alkaloids, xanthones, terpenes, anthraquinones, sterols, diphenyl ethers, pyrones, cyclopentenones, and polyketides with a range of bioactivities. has capacity to produce various enzymes with marked industrial and biotechnological potential, including α-amylases, lipases, xylanases, cellulases, keratinases, and tannases. Also, this fungus has the capacity for bioremediation as well as the biocatalysis of various chemical reactions. The current work aimed at focusing on the bright side of this fungus. In this review, published studies on isolated metabolites from , including their structures, biological functions, and biosynthesis, as well as the biotechnological and industrial significance of this fungus, were highlighted. More than 245 compounds were described in the current review with 134 references published within the period from 1975 to June 2023.
Topics: Animals; Ecosystem; Aspergillus; Anthozoa; Anthraquinones
PubMed: 37623723
DOI: 10.3390/md21080441 -
Annual Review of Animal Biosciences Feb 2024Selective breeding of resilient organisms is an emerging topic in marine conservation. It can help us predict how species will adapt in the future and how we can help... (Review)
Review
Selective breeding of resilient organisms is an emerging topic in marine conservation. It can help us predict how species will adapt in the future and how we can help restore struggling populations effectively in the present. Scleractinian corals represent a potential tractable model system given their widescale phenotypic plasticity across fitness-related traits and a reproductive life history based on mass synchronized spawning. Here, I explore the justification for breeding in corals, identify underutilized pathways of acclimation, and highlight avenues for quantitative targeted breeding from the coral host and symbiont perspective. Specifically, the facilitation of enhanced heat tolerance by targeted breeding of plasticity mechanisms is underutilized. Evidence from theoretical genetics identifies potential pitfalls, including inattention to physical and genetic characteristics of the receiving environment. Three criteria for breeding emerge from this synthesis: selection from warm, variable reefs that have survived disturbance. This information will be essential to protect what we have and restore what we can.
Topics: Animals; Global Warming; Adaptation, Physiological; Anthozoa; Phenotype; Reproduction
PubMed: 37931139
DOI: 10.1146/annurev-animal-021122-093315 -
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 -
Biological Reviews of the Cambridge... Oct 2023The deep sea is amongst the most food-limited habitats on Earth, as only a small fraction (<4%) of the surface primary production is exported below 200 m water depth.... (Review)
Review
The deep sea is amongst the most food-limited habitats on Earth, as only a small fraction (<4%) of the surface primary production is exported below 200 m water depth. Here, cold-water coral (CWC) reefs form oases of life: their biodiversity compares with tropical coral reefs, their biomass and metabolic activity exceed other deep-sea ecosystems by far. We critically assess the paradox of thriving CWC reefs in the food-limited deep sea, by reviewing the literature and open-access data on CWC habitats. This review shows firstly that CWCs typically occur in areas where the food supply is not constantly low, but undergoes pronounced temporal variation. High currents, downwelling and/or vertically migrating zooplankton temporally boost the export of surface organic matter to the seabed, creating 'feast' conditions, interspersed with 'famine' periods during the non-productive season. Secondly, CWCs, particularly the most common reef-builder Desmophyllum pertusum (formerly known as Lophelia pertusa), are well adapted to these fluctuations in food availability. Laboratory and in situ measurements revealed their dietary flexibility, tissue reserves, and temporal variation in growth and energy allocation. Thirdly, the high structural and functional diversity of CWC reefs increases resource retention: acting as giant filters and sustaining complex food webs with diverse recycling pathways, the reefs optimise resource gains over losses. Anthropogenic pressures, including climate change and ocean acidification, threaten this fragile equilibrium through decreased resource supply, increased energy costs, and dissolution of the calcium-carbonate reef framework. Based on this review, we suggest additional criteria to judge the health of CWC reefs and their chance to persist in the future.
Topics: Animals; Coral Reefs; Ecosystem; Hydrogen-Ion Concentration; Seawater; Anthozoa; Water
PubMed: 37236916
DOI: 10.1111/brv.12976