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Williams A. Multiomics data integration, limitations, and prospects to reveal the metabolic activity of the coral holobiont. FEMS Microbiol Ecol 2024; 100:fiae058. [PMID: 38653719 PMCID: PMC11067971 DOI: 10.1093/femsec/fiae058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Revised: 03/25/2024] [Accepted: 04/22/2024] [Indexed: 04/25/2024] Open
Abstract
Since their radiation in the Middle Triassic period ∼240 million years ago, stony corals have survived past climate fluctuations and five mass extinctions. Their long-term survival underscores the inherent resilience of corals, particularly when considering the nutrient-poor marine environments in which they have thrived. However, coral bleaching has emerged as a global threat to coral survival, requiring rapid advancements in coral research to understand holobiont stress responses and allow for interventions before extensive bleaching occurs. This review encompasses the potential, as well as the limits, of multiomics data applications when applied to the coral holobiont. Synopses for how different omics tools have been applied to date and their current restrictions are discussed, in addition to ways these restrictions may be overcome, such as recruiting new technology to studies, utilizing novel bioinformatics approaches, and generally integrating omics data. Lastly, this review presents considerations for the design of holobiont multiomics studies to support lab-to-field advancements of coral stress marker monitoring systems. Although much of the bleaching mechanism has eluded investigation to date, multiomic studies have already produced key findings regarding the holobiont's stress response, and have the potential to advance the field further.
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Affiliation(s)
- Amanda Williams
- Microbial Biology Graduate Program, Rutgers University, 76 Lipman Drive, New Brunswick, NJ 08901, United States
- Department of Biochemistry and Microbiology, Rutgers University, 76 Lipman Drive, New Brunswick, NJ 08901, United States
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2
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Quinlan ZA, Bennett MJ, Arts MGI, Levenstein M, Flores D, Tholen HM, Tichy L, Juarez G, Haas AF, Chamberland VF, Latijnhouwers KRW, Vermeij MJA, Johnson AW, Marhaver KL, Kelly LW. Coral larval settlement induction using tissue-associated and exuded coralline algae metabolites and the identification of putative chemical cues. Proc Biol Sci 2023; 290:20231476. [PMID: 37848062 PMCID: PMC10581770 DOI: 10.1098/rspb.2023.1476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 09/13/2023] [Indexed: 10/19/2023] Open
Abstract
Reef-building crustose coralline algae (CCA) are known to facilitate the settlement and metamorphosis of scleractinian coral larvae. In recent decades, CCA coverage has fallen globally and degrading environmental conditions continue to reduce coral survivorship, spurring new restoration interventions to rebuild coral reef health. In this study, naturally produced chemical compounds (metabolites) were collected from two pantropical CCA genera to isolate and classify those that induce coral settlement. In experiments using four ecologically important Caribbean coral species, we demonstrate the applicability of extracted, CCA-derived metabolites to improve larval settlement success in coral breeding and restoration efforts. Tissue-associated CCA metabolites induced settlement of one coral species, Orbicella faveolata, while metabolites exuded by CCA (exometabolites) induced settlement of three species: Acropora palmata, Colpophyllia natans and Orbicella faveolata. In a follow-up experiment, CCA exometabolites fractionated and preserved using two different extraction resins induced the same level of larval settlement as the unfractionated positive control exometabolites. The fractionated CCA exometabolite pools were characterized using liquid chromatography tandem mass spectrometry, yielding 145 distinct molecular subnetworks that were statistically defined as CCA-derived and could be classified into 10 broad chemical classes. Identifying these compounds can reveal their natural prevalence in coral reef habitats and facilitate the development of new applications to enhance larval settlement and the survival of coral juveniles.
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Affiliation(s)
- Zachary A. Quinlan
- Marine Biology Research Division, Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92093, USA
| | | | - Milou G. I. Arts
- Department of Marine Microbiology and Biogeochemistry, Royal Netherlands Institute of Sea Research (NIOZ), Den Burg, 1797 SZ, Texel, The Netherlands
| | - Mark Levenstein
- Department of Mechanical Science and Engineering, University of Illinois Urbana–Champaign, Urbana, IL 61801, USA
- Institute for Genomic Biology, University of Illinois Urbana–Champaign, Urbana, IL 61801, USA
| | - Daisy Flores
- CARMABI Foundation, Piscaderabaai z/n, Willemstad, Curaçao
- Department of Integrative Biology, University of Texas at Austin, Austin, TX 78712, USA
| | - Haley M. Tholen
- Department of Mechanical Science and Engineering, University of Illinois Urbana–Champaign, Urbana, IL 61801, USA
| | - Lucas Tichy
- CARMABI Foundation, Piscaderabaai z/n, Willemstad, Curaçao
- Department of Microbiology, Radboud University, Nijmegen, 6525 XZ, The Netherlands
| | - Gabriel Juarez
- Department of Mechanical Science and Engineering, University of Illinois Urbana–Champaign, Urbana, IL 61801, USA
| | - Andreas F. Haas
- Department of Marine Microbiology and Biogeochemistry, Royal Netherlands Institute of Sea Research (NIOZ), Den Burg, 1797 SZ, Texel, The Netherlands
- Department of Biology, San Diego State University, San Diego, CA 92182, USA
| | - Valérie F. Chamberland
- CARMABI Foundation, Piscaderabaai z/n, Willemstad, Curaçao
- SECORE International, Hilliard, OH 43026, USA
- Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, 1012 WP, The Netherlands
| | - Kelly R. W. Latijnhouwers
- CARMABI Foundation, Piscaderabaai z/n, Willemstad, Curaçao
- SECORE International, Hilliard, OH 43026, USA
- Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, 1012 WP, The Netherlands
| | - Mark J. A. Vermeij
- CARMABI Foundation, Piscaderabaai z/n, Willemstad, Curaçao
- Department of Freshwater and Marine Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, 1012 WP, The Netherlands
| | - Amy Wagoner Johnson
- Department of Mechanical Science and Engineering, University of Illinois Urbana–Champaign, Urbana, IL 61801, USA
- Institute for Genomic Biology, University of Illinois Urbana–Champaign, Urbana, IL 61801, USA
- Carle Illinois College of Medicine, University of Illinois Urbana–Champaign, Urbana, IL 61801, USA
| | | | - Linda Wegley Kelly
- Marine Biology Research Division, Scripps Institution of Oceanography, University of California San Diego, La Jolla, CA 92093, USA
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3
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Alker AT, Farrell MV, Demko AM, Purdy TN, Adak S, Moore BS, Sneed JM, Paul VJ, Shikuma NJ. Linking bacterial tetrabromopyrrole biosynthesis to coral metamorphosis. ISME COMMUNICATIONS 2023; 3:98. [PMID: 37726481 PMCID: PMC10509201 DOI: 10.1038/s43705-023-00309-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 08/30/2023] [Accepted: 09/11/2023] [Indexed: 09/21/2023]
Abstract
An important factor dictating coral fitness is the quality of bacteria associated with corals and coral reefs. One way that bacteria benefit corals is by stimulating the larval to juvenile life cycle transition of settlement and metamorphosis. Tetrabromopyrrole (TBP) is a small molecule produced by bacteria that stimulates metamorphosis with and without attachment in a range of coral species. A standing debate remains, however, about whether TBP biosynthesis from live Pseudoalteromonas bacteria is the primary stimulant of coral metamorphosis. In this study, we create a Pseudoalteromonas sp. PS5 mutant lacking the TBP brominase gene, bmp2. Using this mutant, we confirm that the bmp2 gene is critical for TBP biosynthesis in Pseudoalteromonas sp. PS5. Mutation of this gene ablates the bacterium's ability in live cultures to stimulate the metamorphosis of the stony coral Porites astreoides. We further demonstrate that expression of TBP biosynthesis genes is strongest in stationary and biofilm modes of growth, where Pseudoalteromonas sp. PS5 might exist within surface-attached biofilms on the sea floor. Finally, we create a modular transposon plasmid for genomic integration and fluorescent labeling of Pseudoalteromonas sp. PS5 cells. Our results functionally link a TBP biosynthesis gene from live bacteria to a morphogenic effect in corals. The genetic techniques established here provide new tools to explore coral-bacteria interactions and could help to inform future decisions about utilizing marine bacteria or their products for coral restoration.
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Affiliation(s)
- Amanda T Alker
- Department of Biology and Viral Information Institute, San Diego State University, San Diego, CA, 92182, USA
| | - Morgan V Farrell
- Department of Biology and Viral Information Institute, San Diego State University, San Diego, CA, 92182, USA
| | | | - Trevor N Purdy
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Sanjoy Adak
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Bradley S Moore
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA, 92093, USA
| | | | | | - Nicholas J Shikuma
- Department of Biology and Viral Information Institute, San Diego State University, San Diego, CA, 92182, USA.
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4
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Alker AT, Farrell MV, Demko AM, Purdy TN, Adak S, Moore BS, Sneed JM, Paul VJ, Shikuma NJ. Linking bacterial tetrabromopyrrole biosynthesis to coral metamorphosis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.08.539906. [PMID: 37214991 PMCID: PMC10197590 DOI: 10.1101/2023.05.08.539906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
An important factor dictating coral fitness is the quality of bacteria associated with corals and coral reefs. One way that bacteria benefit corals is by stimulating the larval to juvenile life cycle transition of settlement and metamorphosis. Tetrabromopyrrole (TBP) is a small molecule produced by bacteria that stimulates metamorphosis in a range of coral species. A standing debate remains, however, about whether TBP biosynthesis from live Pseudoalteromonas bacteria is the primary stimulant of coral metamorphosis. In this study, we create a Pseudoalteromonas sp. PS5 mutant lacking the TBP brominase gene, bmp2 . Using this mutant, we confirm that the bmp2 gene is critical for TBP biosynthesis in Pseudoalteromonas sp. PS5. Mutation of this gene ablates the bacterium's ability in live cultures to stimulate the metamorphosis of the stony coral Porites astreoides . We further demonstrate that expression of TBP biosynthesis genes is strongest in stationary and biofilm modes of growth, where Pseudoalteromonas sp. PS5 might exist within surface-attached biofilms on the sea floor. Finally, we create a modular transposon plasmid for genomic integration and fluorescent labeling of Pseudoalteromonas sp. PS5 cells. Our results functionally link a TBP biosynthesis gene from live bacteria to a morphogenic effect in corals. The genetic techniques established here provide new tools to explore coral-bacteria interactions and could help to inform future decisions about utilizing marine bacteria or their products for restoring degraded coral reefs.
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5
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Alderdice R, Pernice M, Cárdenas A, Hughes DJ, Harrison PL, Boulotte N, Chartrand K, Kühl M, Suggett DJ, Voolstra CR. Hypoxia as a physiological cue and pathological stress for coral larvae. Mol Ecol 2021; 31:571-587. [PMID: 34716959 DOI: 10.1111/mec.16259] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 10/15/2021] [Accepted: 10/20/2021] [Indexed: 11/30/2022]
Abstract
Ocean deoxygenation events are intensifying worldwide and can rapidly drive adult corals into a state of metabolic crisis and bleaching-induced mortality, but whether coral larvae are subject to similar stress remains untested. We experimentally exposed apo-symbiotic coral larvae of Acropora selago to deoxygenation stress with subsequent reoxygenation aligned to their night-day light cycle, and followed their gene expression using RNA-Seq. After 12 h of deoxygenation stress (~2 mg O2 /L), coral planulae demonstrated a low expression of HIF-targeted hypoxia response genes concomitant with a significantly high expression of PHD2 (a promoter of HIFα proteasomal degradation), similar to corresponding adult corals. Despite exhibiting a consistent swimming phenotype compared to control samples, the differential gene expression observed in planulae exposed to deoxygenation-reoxygenation suggests a disruption of pathways involved in developmental regulation, mitochondrial activity, lipid metabolism, and O2 -sensitive epigenetic regulators. Importantly, we found that treated larvae exhibited a disruption in the expression of conserved HIF-targeted developmental regulators, for example, Homeobox (HOX) genes, corroborating how changes in external oxygen levels can affect animal development. We discuss how the observed deoxygenation responses may be indicative of a possible acclimation response or alternatively may imply negative latent impacts for coral larval fitness.
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Affiliation(s)
- Rachel Alderdice
- Faculty of Science, Climate Change Cluster, University of Technology Sydney, Ultimo, NSW, Australia
| | - Mathieu Pernice
- Faculty of Science, Climate Change Cluster, University of Technology Sydney, Ultimo, NSW, Australia
| | - Anny Cárdenas
- Department of Biology, University of Konstanz, Konstanz, Germany
| | - David J Hughes
- Faculty of Science, Climate Change Cluster, University of Technology Sydney, Ultimo, NSW, Australia
| | - Peter L Harrison
- Marine Ecology Research Centre, Southern Cross University, Lismore, NSW, Australia
| | - Nadine Boulotte
- Marine Ecology Research Centre, Southern Cross University, Lismore, NSW, Australia
| | - Katie Chartrand
- Centre of Tropical Water and Aquatic Ecosystem Research, James Cook University, Townsville, Qld, Australia
| | - Michael Kühl
- Faculty of Science, Climate Change Cluster, University of Technology Sydney, Ultimo, NSW, Australia.,Marine Biology Section, Department of Biology, University of Copenhagen, Helsingør, Denmark
| | - David J Suggett
- Faculty of Science, Climate Change Cluster, University of Technology Sydney, Ultimo, NSW, Australia
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6
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Abstract
The diversified NF-κB transcription factor family has been extensively characterized in organisms ranging from flies to humans. However, homologs of NF-κB and many upstream signaling components have recently been characterized in basal phyla, including Cnidaria (sea anemones, corals, hydras, and jellyfish), Porifera (sponges), and single-celled protists, including Capsaspora owczarzaki and some choanoflagellates. Herein, we review what is known about basal NF-κBs and how that knowledge informs on the evolution and conservation of key sequences and domains in NF-κB, as well as the regulation of NF-κB activity. The structures and DNA-binding activities of basal NF-κB proteins resemble those of mammalian NF-κB p100 proteins, and their posttranslational activation appears to have aspects of both canonical and noncanonical pathways in mammals. Several studies suggest that the single NF-κB proteins found in some basal organisms have dual roles in development and immunity. Further research on NF-κB in invertebrates will reveal information about the evolutionary roots of this major signaling pathway, will shed light on the origins of regulated innate immunity, and may have relevance to our understanding of the responses of ecologically important organisms to changing environmental conditions and emerging pathogen-based diseases.
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Affiliation(s)
- Leah M Williams
- Department of Biology, Boston University, Boston, Massachusetts, USA
| | - Thomas D Gilmore
- Department of Biology, Boston University, Boston, Massachusetts, USA
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7
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Aguilar C, Raina JB, Fôret S, Hayward DC, Lapeyre B, Bourne DG, Miller DJ. Transcriptomic analysis reveals protein homeostasis breakdown in the coral Acropora millepora during hypo-saline stress. BMC Genomics 2019; 20:148. [PMID: 30786881 PMCID: PMC6381741 DOI: 10.1186/s12864-019-5527-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 02/13/2019] [Indexed: 11/18/2022] Open
Abstract
Background Coral reefs can experience salinity fluctuations due to rainfall and runoff; these events can have major impacts on the corals and lead to bleaching and mortality. On the Great Barrier Reef (GBR), low salinity events, which occur during summer seasons and can involve salinity dropping ~ 10 PSU correlate with declines in coral cover, and these events are predicted to increase in frequency and severity under future climate change scenarios. In other marine invertebrates, exposure to low salinity causes increased expression of genes involved in proteolysis, responses to oxidative stress, and membrane transport, but the effects that changes in salinity have on corals have so far received only limited attention. To better understand the coral response to hypo-osmotic stress, here we investigated the transcriptomic response of the coral Acropora millepora in both adult and juvenile life stages to acute (1 h) and more prolonged (24 h) exposure to low salinity. Results Differential gene expression analysis revealed the involvement of both common and specific response mechanisms in Acropora. The general response to environmental stressors included up-regulation of genes involved in the mitigation of macromolecular and oxidative damage, while up-regulation of genes involved in amino acid metabolism and transport represent specific responses to salinity stress. Conclusions This study is the first comprehensive transcriptomic analysis of the coral response to low salinity stress and provides important insights into the likely consequences of heavy rainfall and runoff events on coral reefs. Electronic supplementary material The online version of this article (10.1186/s12864-019-5527-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Catalina Aguilar
- AIMS@JCU and Department of Molecular and Cell Biology, James Cook University, Townsville, Queensland, 4811, Australia.,ARC Centre of Excellence for Coral Reef Studies and Department of Molecular and Cell Biology, James Cook University, Townsville, Queensland, 4811, Australia.,Cooperative Institute for Marine and Atmospheric Studies, Rosenstiel School of Marine & Atmospheric Science, University of Miami, 4600 Rickenbacker Causeway, Miami, Florida, 33149, USA.,Atlantic Oceanographic and Meteorological Laboratories (AOML), NOAA, 4301 Rickenbacker Causeway, Miami, Florida, 33149, USA
| | - Jean-Baptiste Raina
- AIMS@JCU and Department of Molecular and Cell Biology, James Cook University, Townsville, Queensland, 4811, Australia.,Climate Change Cluster (C3), University of Technology, Sydney, NSW, 2007, Australia
| | - Sylvain Fôret
- ARC Centre of Excellence for Coral Reef Studies and Department of Molecular and Cell Biology, James Cook University, Townsville, Queensland, 4811, Australia.,Division of Ecology and Evolution, Research School of Biology, Australian National University, Canberra, ACT, 2601, Australia
| | - David C Hayward
- Division of Ecology and Evolution, Research School of Biology, Australian National University, Canberra, ACT, 2601, Australia
| | - Bruno Lapeyre
- Laboratoire d'excellence CORAIL, Centre de Recherches Insulaires et Observatoire de l'Environnement (CRIOBE), Moorea, B.P.1013, Papeete, French Polynesia
| | - David G Bourne
- AIMS@JCU and Department of Molecular and Cell Biology, James Cook University, Townsville, Queensland, 4811, Australia.,Australian Institute of Marine Science, Townsville, Queensland, 4810, Australia.,College of Science and Engineering, James Cook University, Townsville, 4811, Australia
| | - David J Miller
- AIMS@JCU and Department of Molecular and Cell Biology, James Cook University, Townsville, Queensland, 4811, Australia. .,ARC Centre of Excellence for Coral Reef Studies and Department of Molecular and Cell Biology, James Cook University, Townsville, Queensland, 4811, Australia.
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8
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Attenborough RM, Hayward DC, Wiedemann U, Forêt S, Miller DJ, Ball EE. Expression of the neuropeptides RFamide and LWamide during development of the coral Acropora millepora in relation to settlement and metamorphosis. Dev Biol 2019; 446:56-67. [DOI: 10.1016/j.ydbio.2018.11.022] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Revised: 11/22/2018] [Accepted: 11/30/2018] [Indexed: 10/27/2022]
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9
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Stepwise metamorphosis of the tubeworm Hydroides elegans is mediated by a bacterial inducer and MAPK signaling. Proc Natl Acad Sci U S A 2016; 113:10097-102. [PMID: 27551098 DOI: 10.1073/pnas.1603142113] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Diverse animal taxa metamorphose between larval and juvenile phases in response to bacteria. Although bacteria-induced metamorphosis is widespread among metazoans, little is known about the molecular changes that occur in the animal upon stimulation by bacteria. Larvae of the tubeworm Hydroides elegans metamorphose in response to surface-bound Pseudoalteromonas luteoviolacea bacteria, producing ordered arrays of phage tail-like metamorphosis-associated contractile structures (MACs). Sequencing the Hydroides genome and transcripts during five developmental stages revealed that MACs induce the regulation of groups of genes important for tissue remodeling, innate immunity, and mitogen-activated protein kinase (MAPK) signaling. Using two MAC mutations that block P. luteoviolacea from inducing settlement or metamorphosis and three MAPK inhibitors, we established a sequence of bacteria-induced metamorphic events: MACs induce larval settlement; then, particular properties of MACs encoded by a specific locus in P. luteoviolacea initiate cilia loss and activate metamorphosis-associated transcription; finally, signaling through p38 and c-Jun N-terminal kinase (JNK) MAPK pathways alters gene expression and leads to morphological changes upon initiation of metamorphosis. Our results reveal that the intricate interaction between Hydroides and P. luteoviolacea can be dissected using genomic, genetic, and pharmacological tools. Hydroides' dependency on bacteria for metamorphosis highlights the importance of external stimuli to orchestrate animal development. The conservation of Hydroides genome content with distantly related deuterostomes (urchins, sea squirts, and humans) suggests that mechanisms of bacteria-induced metamorphosis in Hydroides may have conserved features in diverse animals. As a major biofouling agent, insight into the triggers of Hydroides metamorphosis might lead to practical strategies for fouling control.
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Tebben J, Motti CA, Siboni N, Tapiolas DM, Negri AP, Schupp PJ, Kitamura M, Hatta M, Steinberg PD, Harder T. Chemical mediation of coral larval settlement by crustose coralline algae. Sci Rep 2015; 5:10803. [PMID: 26042834 PMCID: PMC4650656 DOI: 10.1038/srep10803] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2015] [Accepted: 04/29/2015] [Indexed: 11/28/2022] Open
Abstract
The majority of marine invertebrates produce dispersive larvae which, in order to complete their life cycles, must attach and metamorphose into benthic forms. This process, collectively referred to as settlement, is often guided by habitat-specific cues. While the sources of such cues are well known, the links between their biological activity, chemical identity, presence and quantification in situ are largely missing. Previous work on coral larval settlement in vitro has shown widespread induction by crustose coralline algae (CCA) and in particular their associated bacteria. However, we found that bacterial biofilms on CCA did not initiate ecologically realistic settlement responses in larvae of 11 hard coral species from Australia, Guam, Singapore and Japan. We instead found that algal chemical cues induce identical behavioral responses of larvae as per live CCA. We identified two classes of CCA cell wall-associated compounds--glycoglycerolipids and polysaccharides--as the main constituents of settlement inducing fractions. These algae-derived fractions induce settlement and metamorphosis at equivalent concentrations as present in CCA, both in small scale laboratory assays and under flow-through conditions, suggesting their ability to act in an ecologically relevant fashion to steer larval settlement of corals. Both compound classes were readily detected in natural samples.
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Affiliation(s)
- J. Tebben
- School of Biological Earth and Environmental Sciences, Centre for Marine Bio-Innovation, The University of New South Wales, Sydney, 2052 NSW, Australia
| | - C. A Motti
- Australian Institute of Marine Science, Townsville, 4810 QLD, Australia
| | - Nahshon Siboni
- Australian Institute of Marine Science, Townsville, 4810 QLD, Australia
- Plant Functional Biology and Climate Change, University of Technology Sydney, Ultimo, 2007 NSW, Australia
| | - D. M. Tapiolas
- Australian Institute of Marine Science, Townsville, 4810 QLD, Australia
| | - A. P. Negri
- Australian Institute of Marine Science, Townsville, 4810 QLD, Australia
| | - P. J. Schupp
- Institute for Chemistry and Biology of the Marine Environment Terramare, University of Oldenburg, 26382 Wilhelmshaven, Germany
| | - Makoto Kitamura
- Okinawa Environment Science Center, Urasoe, Okinawa 901-2111, Japan
| | - Masayuki Hatta
- Graduate School of Humanities and Sciences, Ochanomizu University, Tokyo 112-8610, Japan
| | - P. D. Steinberg
- School of Biological Earth and Environmental Sciences, Centre for Marine Bio-Innovation, The University of New South Wales, Sydney, 2052 NSW, Australia
- Sydney Institute of Marine Science, Mosman, 2088 NSW, Australia
- Advanced Environmental Biotechnology Centre, Nanyang Technological University, Singapore 639798, Singapore
| | - T. Harder
- School of Biological Earth and Environmental Sciences, Centre for Marine Bio-Innovation, The University of New South Wales, Sydney, 2052 NSW, Australia
- Australian Institute of Marine Science, Townsville, 4810 QLD, Australia
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11
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Sharp KH, Sneed JM, Ritchie KB, Mcdaniel L, Paul VJ. Induction of Larval Settlement in the Reef Coral Porites astreoides by a Cultivated Marine Roseobacter Strain. THE BIOLOGICAL BULLETIN 2015; 228:98-107. [PMID: 25920713 DOI: 10.1086/bblv228n2p98] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Successful larval settlement and recruitment by corals is critical for the survival of coral reef ecosystems. Several closely related strains of γ-proteobacteria have been identified as cues for coral larval settlement, but the inductive properties of other bacterial taxa naturally occurring in reef ecosystems have not yet been explored. In this study, we assayed bacterial strains representing taxonomic groups consistently detected in corals for their ability to influence larval settlement in the coral Porites astreoides. We identified one α-proteobacterial strain, Roseivivax sp. 46E8, which significantly increased larval settlement in P. astreoides. Logarithmic growth phase (log phase) cell cultures of Roseivivax sp. 46E8 and filtrates (0.22μm) from log phase Roseivivax sp. 46E8 cultures significantly increased settlement, suggesting that an extracellular settlement factor is produced during active growth phase. Filtrates from log phase cultures of two other bacterial isolates, Marinobacter sp. 46E3, and Cytophaga sp. 46B6, also significantly increased settlement, but the cell cultures themselves did not. Monospecific biofilms of the three strains did not result in significant increases in larval settlement. Organic and aqueous/methanol extracts of Roseivivax sp. 46E8 cultures did not affect larval settlement. Examination of filtrates from cell cultures showed that Roseivivax sp. 46E8 spontaneously generated virus-like particles in log and stationary phase growth. Though the mechanism of settlement enhancement by Roseivivax sp. 46E8 is not yet elucidated, our findings point to a new aspect of coral-Roseobacter interactions that should be further investigated, especially in naturally occurring, complex microbial biofilms on reef surfaces.
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Affiliation(s)
- K H Sharp
- Eckerd College, 4200 54th Avenue South, St. Petersburg, Florida 33711;
| | - J M Sneed
- Smithsonian Marine Station, 701 Seaway Drive, Fort Pierce, Florida 34949
| | - K B Ritchie
- Mote Marine Laboratory, 1600 Ken Thompson Pkwy, Sarasota, Florida 34236; and
| | - L Mcdaniel
- University of South Florida College of Marine Science, 140 7th Avenue S., St. Petersburg, Florida 33701
| | - V J Paul
- Smithsonian Marine Station, 701 Seaway Drive, Fort Pierce, Florida 34949
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12
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Sinigaglia C, Busengdal H, Lerner A, Oliveri P, Rentzsch F. Molecular characterization of the apical organ of the anthozoan Nematostella vectensis. Dev Biol 2015; 398:120-33. [PMID: 25478911 PMCID: PMC4300403 DOI: 10.1016/j.ydbio.2014.11.019] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Revised: 10/16/2014] [Accepted: 11/13/2014] [Indexed: 02/07/2023]
Abstract
Apical organs are sensory structures present in many marine invertebrate larvae where they are considered to be involved in their settlement, metamorphosis and locomotion. In bilaterians they are characterised by a tuft of long cilia and receptor cells and they are associated with groups of neurons, but their relatively low morphological complexity and dispersed phylogenetic distribution have left their evolutionary relationship unresolved. Moreover, since apical organs are not present in the standard model organisms, their development and function are not well understood. To provide a foundation for a better understanding of this structure we have characterised the molecular composition of the apical organ of the sea anemone Nematostella vectensis. In a microarray-based comparison of the gene expression profiles of planulae with either a wildtype or an experimentally expanded apical organ, we identified 78 evolutionarily conserved genes, which are predominantly or specifically expressed in the apical organ of Nematostella. This gene set comprises signalling molecules, transcription factors, structural and metabolic genes. The majority of these genes, including several conserved, but previously uncharacterized ones, are potentially involved in different aspects of the development or function of the long cilia of the apical organ. To demonstrate the utility of this gene set for comparative analyses, we further analysed the expression of a subset of previously uncharacterized putative orthologs in sea urchin larvae and detected expression for twelve out of eighteen of them in the apical domain. Our study provides a molecular characterization of the apical organ of Nematostella and represents an informative tool for future studies addressing the development, function and evolutionary history of apical organ cells.
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Affiliation(s)
- Chiara Sinigaglia
- Sars Centre for Marine Molecular Biology, University of Bergen, Thormøhlensgt 55, 5008 Bergen, Norway
| | - Henriette Busengdal
- Sars Centre for Marine Molecular Biology, University of Bergen, Thormøhlensgt 55, 5008 Bergen, Norway
| | - Avi Lerner
- Department of Genetics, Evolution and Environment, University College London, Gower Street, London WC1E 6BT, UK
| | - Paola Oliveri
- Department of Genetics, Evolution and Environment, University College London, Gower Street, London WC1E 6BT, UK
| | - Fabian Rentzsch
- Sars Centre for Marine Molecular Biology, University of Bergen, Thormøhlensgt 55, 5008 Bergen, Norway.
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Hemond EM, Kaluziak ST, Vollmer SV. The genetics of colony form and function in Caribbean Acropora corals. BMC Genomics 2014; 15:1133. [PMID: 25519925 PMCID: PMC4320547 DOI: 10.1186/1471-2164-15-1133] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Accepted: 12/11/2014] [Indexed: 12/22/2022] Open
Abstract
Background Colonial reef-building corals have evolved a broad spectrum of colony morphologies based on coordinated asexual reproduction of polyps on a secreted calcium carbonate skeleton. Though cnidarians have been shown to possess and use similar developmental genes to bilaterians during larval development and polyp formation, little is known about genetic regulation of colony morphology in hard corals. We used RNA-seq to evaluate transcriptomic differences between functionally distinct regions of the coral (apical branch tips and branch bases) in two species of Caribbean Acropora, the staghorn coral, A. cervicornis, and the elkhorn coral, A. palmata. Results Transcriptome-wide gene profiles differed significantly between different parts of the coral colony as well as between species. Genes showing differential expression between branch tips and bases were involved in developmental signaling pathways, such as Wnt, Notch, and BMP, as well as pH regulation, ion transport, extracellular matrix production and other processes. Differences both within colonies and between species identify a relatively small number of genes that may contribute to the distinct “staghorn” versus “elkhorn” morphologies of these two sister species. Conclusions The large number of differentially expressed genes supports a strong division of labor between coral branch tips and branch bases. Genes involved in growth of mature Acropora colonies include the classical signaling pathways associated with development of cnidarian larvae and polyps as well as morphological determination in higher metazoans. Electronic supplementary material The online version of this article (doi:10.1186/1471-2164-15-1133) contains supplementary material, which is available to authorized users.
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Elran R, Raam M, Kraus R, Brekhman V, Sher N, Plaschkes I, Chalifa-Caspi V, Lotan T. Early and late response of Nematostella vectensis transcriptome to heavy metals. Mol Ecol 2014; 23:4722-36. [PMID: 25145541 DOI: 10.1111/mec.12891] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Revised: 07/22/2014] [Accepted: 08/13/2014] [Indexed: 12/28/2022]
Abstract
Environmental contamination from heavy metals poses a global concern for the marine environment, as heavy metals are passed up the food chain and persist in the environment long after the pollution source is contained. Cnidarians play an important role in shaping marine ecosystems, but environmental pollution profoundly affects their vitality. Among the cnidarians, the sea anemone Nematostella vectensis is an advantageous model for addressing questions in molecular ecology and toxicology as it tolerates extreme environments and its genome has been published. Here, we employed a transcriptome-wide RNA-Seq approach to analyse N. vectensis molecular defence mechanisms against four heavy metals: Hg, Cu, Cd and Zn. Altogether, more than 4800 transcripts showed significant changes in gene expression. Hg had the greatest impact on up-regulating transcripts, followed by Cu, Zn and Cd. We identified, for the first time in Cnidaria, co-up-regulation of immediate-early transcription factors such as Egr1, AP1 and NF-κB. Time-course analysis of these genes revealed their early expression as rapidly as one hour after exposure to heavy metals, suggesting that they may complement or substitute for the roles of the metal-mediating Mtf1 transcription factor. We further characterized the regulation of a large array of stress-response gene families, including Hsp, ABC, CYP members and phytochelatin synthase, that may regulate synthesis of the metal-binding phytochelatins instead of the metallothioneins that are absent from Cnidaria genome. This study provides mechanistic insight into heavy metal toxicity in N. vectensis and sheds light on ancestral stress adaptations.
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Affiliation(s)
- Ron Elran
- Marine Biology Department, The Leon H. Charney School of Marine Sciences, University of Haifa, Haifa, Israel
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