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Wuitchik DM, Aichelman HE, Atherton KF, Brown CM, Chen X, DiRoberts L, Pelose GE, Tramonte CA, Davies SW. Photosymbiosis reduces the environmental stress response under a heat challenge in a facultatively symbiotic coral. Sci Rep 2024; 14:15484. [PMID: 38969663 PMCID: PMC11226616 DOI: 10.1038/s41598-024-66057-2] [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: 01/11/2024] [Accepted: 06/26/2024] [Indexed: 07/07/2024] Open
Abstract
The symbiosis between corals and dinoflagellates of the family Symbiodiniaceae is sensitive to environmental stress. The oxidative bleaching hypothesis posits that extreme temperatures lead to accumulation of photobiont-derived reactive oxygen species ROS, which exacerbates the coral environmental stress response (ESR). To understand how photosymbiosis modulates coral ESRs, these responses must be explored in hosts in and out of symbiosis. We leveraged the facultatively symbiotic coral Astrangia poculata, which offers an opportunity to uncouple the ESR across its two symbiotic phenotypes (brown, white). Colonies of both symbiotic phenotypes were exposed to three temperature treatments for 15 days: (i) control (static 18 °C), (ii) heat challenge (increasing from 18 to 30 °C), and (iii) cold challenge (decreasing from 18 to 4 °C) after which host gene expression was profiled. Cold challenged corals elicited widespread differential expression, however, there were no differences between symbiotic phenotypes. In contrast, brown colonies exhibited greater gene expression plasticity under heat challenge, including enrichment of cell cycle pathways involved in controlling photobiont growth. While this plasticity was greater, the genes driving this plasticity were not associated with an amplified environmental stress response (ESR) and instead showed patterns of a dampened ESR under heat challenge. This provides nuance to the oxidative bleaching hypothesis and suggests that, at least during the early onset of bleaching, photobionts reduce the host's ESR under elevated temperatures in A. poculata.
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Affiliation(s)
- D M Wuitchik
- Department of Biology, Boston University, Boston, MA, USA.
- Department of Biology, Tufts University, Medford, MA, USA.
| | - H E Aichelman
- Department of Biology, Boston University, Boston, MA, USA
| | - K F Atherton
- Department of Biology, Boston University, Boston, MA, USA
- Bioinformatics Graduate Program, Boston University, Boston, MA, USA
| | - C M Brown
- Department of Biology, Boston University, Boston, MA, USA
| | - X Chen
- Department of Biology, Boston University, Boston, MA, USA
| | - L DiRoberts
- Department of Biology, Boston University, Boston, MA, USA
| | - G E Pelose
- Department of Biology, Boston University, Boston, MA, USA
| | - C A Tramonte
- Department of Biology, Boston College, Boston, MA, USA
| | - S W Davies
- Department of Biology, Boston University, Boston, MA, USA.
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2
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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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3
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Aichelman HE, Huzar AK, Wuitchik DM, Atherton KF, Wright RM, Dixon G, Schlatter E, Haftel N, Davies SW. Symbiosis modulates gene expression of symbionts, but not coral hosts, under thermal challenge. Mol Ecol 2024; 33:e17318. [PMID: 38488669 DOI: 10.1111/mec.17318] [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: 11/22/2023] [Revised: 02/23/2024] [Accepted: 03/01/2024] [Indexed: 04/09/2024]
Abstract
Increasing ocean temperatures are causing dysbiosis between coral hosts and their symbionts. Previous work suggests that coral host gene expression responds more strongly to environmental stress compared to their intracellular symbionts; however, the causes and consequences of this phenomenon remain untested. We hypothesized that symbionts are less responsive because hosts modulate symbiont environments to buffer stress. To test this hypothesis, we leveraged the facultative symbiosis between the scleractinian coral Oculina arbuscula and its symbiont Breviolum psygmophilum to characterize gene expression responses of both symbiotic partners in and ex hospite under thermal challenges. To characterize host and in hospite symbiont responses, symbiotic and aposymbiotic O. arbuscula were exposed to three treatments: (1) control (18°C), (2) heat (32°C), and (3) cold (6°C). This experiment was replicated with B. psygmophilum cultured from O. arbuscula to characterize ex hospite symbiont responses. Both thermal challenges elicited classic environmental stress responses (ESRs) in O. arbuscula regardless of symbiotic state, with hosts responding more strongly to cold challenge. Hosts also exhibited stronger responses than in hospite symbionts. In and ex hospite B. psygmophilum both down-regulated gene ontology pathways associated with photosynthesis under thermal challenge; however, ex hospite symbionts exhibited greater gene expression plasticity and differential expression of genes associated with ESRs. Taken together, these findings suggest that O. arbuscula hosts may buffer environments of B. psygmophilum symbionts; however, we outline the future work needed to confirm this hypothesis.
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Affiliation(s)
| | - Alexa K Huzar
- Department of Biology, Boston University, Boston, Massachusetts, USA
| | - Daniel M Wuitchik
- Department of Biology, Boston University, Boston, Massachusetts, USA
| | | | - Rachel M Wright
- Department of Biology, Boston University, Boston, Massachusetts, USA
| | - Groves Dixon
- Department of Integrative Biology, University of Texas at Austin, Austin, Texas, USA
| | - E Schlatter
- Department of Biology, Boston University, Boston, Massachusetts, USA
| | - Nicole Haftel
- Department of Biology, Boston University, Boston, Massachusetts, USA
| | - Sarah W Davies
- Department of Biology, Boston University, Boston, Massachusetts, USA
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4
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Strader ME, Wright RM, Pezner AK, Nuttall MF, Aichelman HE, Davies SW. Intersection of coral molecular responses to a localized mortality event and ex situ deoxygenation. Ecol Evol 2024; 14:e11275. [PMID: 38654712 PMCID: PMC11036075 DOI: 10.1002/ece3.11275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Revised: 03/22/2024] [Accepted: 04/01/2024] [Indexed: 04/26/2024] Open
Abstract
In July 2016, East Bank of Flower Garden Banks (FGB) National Marine Sanctuary experienced a localized mortality event (LME) of multiple invertebrate species that ultimately led to reductions in coral cover. Abiotic data taken directly after the event suggested that acute deoxygenation contributed to the mortality. Despite the large impact of this event on the coral community, there was no direct evidence that this LME was driven by acute deoxygenation, and thus we explored whether gene expression responses of corals to the LME would indicate what abiotic factors may have contributed to the LME. Gene expression of affected and unaffected corals sampled during the mortality event revealed evidence of the physiological consequences of the LME on coral hosts and their algal symbionts from two congeneric species (Orbicella franksi and Orbicella faveolata). Affected colonies of both species differentially regulated genes involved in mitochondrial regulation and oxidative stress. To further test the hypothesis that deoxygenation led to the LME, we measured coral host and algal symbiont gene expression in response to ex situ experimental deoxygenation (control = 6.9 ± 0.08 mg L-1, anoxic = 0.083 ± 0.017 mg L-1) in healthy O. faveolata colonies from the FGB. However, this deoxygenation experiment revealed divergent gene expression patterns compared to the corals sampled during the LME and was more similar to a generalized coral environmental stress response. It is therefore likely that while the LME was connected to low oxygen, it was a series of interconnected stressors that elicited the unique gene expression responses observed here. These in situ and ex situ data highlight how field responses to stressors are unique from those in controlled laboratory conditions, and that the complexities of deoxygenation events in the field likely arise from interactions between multiple environmental factors simultaneously.
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Affiliation(s)
- Marie E. Strader
- Department of BiologyTexas A&M UniversityCollege StationTexasUSA
| | - Rachel M. Wright
- Department of Biological SciencesSouthern Methodist UniversityDallasTexasUSA
| | | | | | | | - Sarah W. Davies
- Department of BiologyBoston UniversityBostonMassachusettsUSA
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5
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Dilworth J, Million WC, Ruggeri M, Hall ER, Dungan AM, Muller EM, Kenkel CD. Synergistic response to climate stressors in coral is associated with genotypic variation in baseline expression. Proc Biol Sci 2024; 291:20232447. [PMID: 38531406 DOI: 10.1098/rspb.2023.2447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Accepted: 02/16/2024] [Indexed: 03/28/2024] Open
Abstract
As environments are rapidly reshaped due to climate change, phenotypic plasticity plays an important role in the ability of organisms to persist and is considered an especially important acclimatization mechanism for long-lived sessile organisms such as reef-building corals. Often, this ability of a single genotype to display multiple phenotypes depending on the environment is modulated by changes in gene expression, which can vary in response to environmental changes via two mechanisms: baseline expression and expression plasticity. We used transcriptome-wide expression profiling of eleven genotypes of common-gardened Acropora cervicornis to explore genotypic variation in the expression response to thermal and acidification stress, both individually and in combination. We show that the combination of these two stressors elicits a synergistic gene expression response, and that both baseline expression and expression plasticity in response to stress show genotypic variation. Additionally, we demonstrate that frontloading of a large module of coexpressed genes is associated with greater retention of algal symbionts under combined stress. These results illustrate that variation in the gene expression response of individuals to climate change stressors can persist even when individuals have shared environmental histories, affecting their performance under future climate change scenarios.
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Affiliation(s)
| | | | - Maria Ruggeri
- University of Southern California, Los Angeles, CA, USA
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6
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Selmoni O, Bay LK, Exposito-Alonso M, Cleves PA. Finding genes and pathways that underlie coral adaptation. Trends Genet 2024; 40:213-227. [PMID: 38320882 DOI: 10.1016/j.tig.2024.01.003] [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: 10/09/2023] [Revised: 01/08/2024] [Accepted: 01/10/2024] [Indexed: 02/08/2024]
Abstract
Mass coral bleaching is one of the clearest threats of climate change to the persistence of marine biodiversity. Despite the negative impacts of bleaching on coral health and survival, some corals may be able to rapidly adapt to warming ocean temperatures. Thus, a significant focus in coral research is identifying the genes and pathways underlying coral heat adaptation. Here, we review state-of-the-art methods that may enable the discovery of heat-adaptive loci in corals and identify four main knowledge gaps. To fill these gaps, we describe an experimental approach combining seascape genomics with CRISPR/Cas9 gene editing to discover and validate heat-adaptive loci. Finally, we discuss how information on adaptive genotypes could be used in coral reef conservation and management strategies.
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Affiliation(s)
- Oliver Selmoni
- Department of Embryology, Carnegie Institution for Science, Baltimore, MD 21218, USA; Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305, USA.
| | - Line K Bay
- Reef Recovery, Adaptation, and Restoration, Australian Institute of Marine Science; Townsville, QLD 4810, Australia
| | - Moises Exposito-Alonso
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305, USA; Department of Biology, Stanford University, Stanford, CA 94305, USA; Department of Global Ecology, Carnegie Institution for Science, Stanford, CA 94305, USA.
| | - Phillip A Cleves
- Department of Embryology, Carnegie Institution for Science, Baltimore, MD 21218, USA; Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA.
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7
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Luter HM, Laffy P, Flores F, Brinkman DL, Fisher R, Negri AP. Molecular responses of sponge larvae exposed to partially weathered condensate oil. MARINE POLLUTION BULLETIN 2024; 199:115928. [PMID: 38141581 DOI: 10.1016/j.marpolbul.2023.115928] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 12/04/2023] [Accepted: 12/10/2023] [Indexed: 12/25/2023]
Abstract
Anthropogenic inputs of petroleum hydrocarbons into the marine environment can have long lasting impacts on benthic communities. Sponges form an abundant and diverse component of benthic habitats, contributing a variety of important functional roles; however, their responses to petroleum hydrocarbons are largely unknown. This study combined a traditional ecotoxicological experimental design and endpoint with global gene expression profiling and microbial indicator species analysis to examine the effects of a water accommodated fraction (WAF) of condensate oil on a common Indo-Pacific sponge, Phyllospongia foliascens. A no significant effect concentration (N(S)EC) of 2.1 % WAF was obtained for larval settlement, while gene-specific (N(S)EC) thresholds ranged from 3.4 % to 8.8 % WAF. Significant shifts in global gene expression were identified at WAF treatments ≥20 %, with larvae exposed to 100 % WAF most responsive. Results from this study provide an example on the incorporation of non-conventional molecular and microbiological responses into ecotoxicological studies on petroleum hydrocarbons.
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Affiliation(s)
- Heidi M Luter
- Australian Institute of Marine Science, Townsville 4810, QLD, Australia; AIMS@JCU, Division of Research & Innovation, James Cook University, Townsville 4811, QLD, Australia.
| | - Patrick Laffy
- Australian Institute of Marine Science, Townsville 4810, QLD, Australia; AIMS@JCU, Division of Research & Innovation, James Cook University, Townsville 4811, QLD, Australia
| | - Florita Flores
- Australian Institute of Marine Science, Townsville 4810, QLD, Australia
| | - Diane L Brinkman
- Australian Institute of Marine Science, Townsville 4810, QLD, Australia
| | - Rebecca Fisher
- Australian Institute of Marine Science, Crawley 6009, WA, Australia
| | - Andrew P Negri
- Australian Institute of Marine Science, Townsville 4810, QLD, Australia; AIMS@JCU, Division of Research & Innovation, James Cook University, Townsville 4811, QLD, Australia
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8
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Studivan MS, Eckert RJ, Shilling E, Soderberg N, Enochs IC, Voss JD. Stony coral tissue loss disease intervention with amoxicillin leads to a reversal of disease-modulated gene expression pathways. Mol Ecol 2023; 32:5394-5413. [PMID: 37646698 DOI: 10.1111/mec.17110] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 07/22/2023] [Accepted: 08/10/2023] [Indexed: 09/01/2023]
Abstract
Stony coral tissue loss disease (SCTLD) remains an unprecedented disease outbreak due to its high mortality rate and rapid spread throughout Florida's Coral Reef and wider Caribbean. A collaborative effort is underway to evaluate strategies that mitigate the spread of SCTLD across coral colonies and reefs, including restoration of disease-resistant genotypes, genetic rescue, and disease intervention with therapeutics. We conducted an in-situ experiment in Southeast Florida to assess molecular responses among SCTLD-affected Montastraea cavernosa pre- and post-application of the most widely used intervention method, CoreRx Base 2B with amoxicillin. Through Tag-Seq gene expression profiling of apparently healthy, diseased, and treated corals, we identified modulation of metabolomic and immune gene pathways following antibiotic treatment. In a complementary ex-situ disease challenge experiment, we exposed nursery-cultured M. cavernosa and Orbicella faveolata fragments to SCTLD-affected donor corals to compare transcriptomic profiles among clonal individuals from unexposed controls, those exposed and displaying disease signs, and corals exposed and not displaying disease signs. Suppression of metabolic functional groups and activation of stress gene pathways as a result of SCTLD exposure were apparent in both species. Amoxicillin treatment led to a 'reversal' of the majority of gene pathways implicated in disease response, suggesting potential recovery of corals following antibiotic application. In addition to increasing our understanding of molecular responses to SCTLD, we provide resource managers with transcriptomic evidence that disease intervention with antibiotics appears to be successful and may help to modulate coral immune responses to SCTLD. These results contribute to feasibility assessments of intervention efforts following disease outbreaks and improved predictions of coral reef health across the wider Caribbean.
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Affiliation(s)
- Michael S Studivan
- Harbor Branch Oceanographic Institute, Florida Atlantic University, Fort Pierce, Florida, USA
- University of Miami, Cooperative Institute for Marine and Atmospheric Studies, Miami, Florida, USA
- Ocean Chemistry and Ecosystems Division, NOAA Atlantic Oceanographic and Meteorological Laboratory, Miami, Florida, USA
| | - Ryan J Eckert
- Harbor Branch Oceanographic Institute, Florida Atlantic University, Fort Pierce, Florida, USA
| | - Erin Shilling
- Harbor Branch Oceanographic Institute, Florida Atlantic University, Fort Pierce, Florida, USA
| | - Nash Soderberg
- University of Miami, Cooperative Institute for Marine and Atmospheric Studies, Miami, Florida, USA
- Ocean Chemistry and Ecosystems Division, NOAA Atlantic Oceanographic and Meteorological Laboratory, Miami, Florida, USA
| | - Ian C Enochs
- Ocean Chemistry and Ecosystems Division, NOAA Atlantic Oceanographic and Meteorological Laboratory, Miami, Florida, USA
| | - Joshua D Voss
- Harbor Branch Oceanographic Institute, Florida Atlantic University, Fort Pierce, Florida, USA
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9
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Dellaert Z, Putnam HM. Reconciling the variability in the biological response of marine invertebrates to climate change. J Exp Biol 2023; 226:jeb245834. [PMID: 37655544 DOI: 10.1242/jeb.245834] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
Abstract
As climate change increases the rate of environmental change and the frequency and intensity of disturbance events, selective forces intensify. However, given the complicated interplay between plasticity and selection for ecological - and thus evolutionary - outcomes, understanding the proximate signals, molecular mechanisms and the role of environmental history becomes increasingly critical for eco-evolutionary forecasting. To enhance the accuracy of our forecasting, we must characterize environmental signals at a level of resolution that is relevant to the organism, such as the microhabitat it inhabits and its intracellular conditions, while also quantifying the biological responses to these signals in the appropriate cells and tissues. In this Commentary, we provide historical context to some of the long-standing challenges in global change biology that constrain our capacity for eco-evolutionary forecasting using reef-building corals as a focal model. We then describe examples of mismatches between the scales of external signals relative to the sensors and signal transduction cascades that initiate and maintain cellular responses. Studying cellular responses at this scale is crucial because these responses are the basis of acclimation to changing environmental conditions and the potential for environmental 'memory' of prior or historical conditions through molecular mechanisms. To challenge the field, we outline some unresolved questions and suggest approaches to align experimental work with an organism's perception of the environment; these aspects are discussed with respect to human interventions.
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Affiliation(s)
- Zoe Dellaert
- Department of Biological Sciences, University of Rhode Island, 120 Flagg Rd, Kingston, RI 02881, USA
| | - Hollie M Putnam
- Department of Biological Sciences, University of Rhode Island, 120 Flagg Rd, Kingston, RI 02881, USA
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10
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Rivera HE, Tramonte CA, Samaroo J, Dickerson H, Davies SW. Heat challenge elicits stronger physiological and gene expression responses than starvation in symbiotic Oculina arbuscula. J Hered 2023; 114:312-325. [PMID: 36921030 DOI: 10.1093/jhered/esac068] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Accepted: 12/09/2022] [Indexed: 03/17/2023] Open
Abstract
Heterotrophy has been shown to mitigate coral-algal dysbiosis (coral bleaching) under heat challenge, but the molecular mechanisms underlying this phenomenon remain largely unexplored. Here, we quantified coral physiology and gene expression of fragments from 13 genotypes of symbiotic Oculina arbuscula after a 28-d feeding experiment under (1) fed, ambient (24 °C); (2) unfed, ambient; (3) fed, heated (ramp to 33 °C); and (4) unfed, heated treatments. We monitored algal photosynthetic efficiency throughout the experiment, and after 28 d, profiled coral and algal carbohydrate and protein reserves, coral gene expression, algal cell densities, and chlorophyll-a and chlorophyll-c2 pigments. Contrary to previous findings, heterotrophy did little to mitigate the impacts of temperature, and we observed few significant differences in physiology between fed and unfed corals under heat challenge. Our results suggest the duration and intensity of starvation and thermal challenge play meaningful roles in coral energetics and stress response; future work exploring these thresholds and how they may impact coral responses under changing climate is urgently needed. Gene expression patterns under heat challenge in fed and unfed corals showed gene ontology enrichment patterns consistent with classic signatures of the environmental stress response. While gene expression differences between fed and unfed corals under heat challenge were subtle: Unfed, heated corals uniquely upregulated genes associated with cell cycle functions, an indication that starvation may induce the previously described, milder "type B" coral stress response. Future studies interested in disentangling the influence of heterotrophy on coral bleaching would benefit from leveraging the facultative species studied here, but using the coral in its symbiotic and aposymbiotic states.
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Affiliation(s)
- Hanny E Rivera
- Department of Biology, Boston University, Boston, MA 02215, USA
| | | | - Jason Samaroo
- Department of Biology, Boston University, Boston, MA 02215, USA
| | | | - Sarah W Davies
- Department of Biology, Boston University, Boston, MA 02215, USA
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11
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Young BD, Rosales SM, Enochs IC, Kolodziej G, Formel N, Moura A, D'Alonso GL, Traylor-Knowles N. Different disease inoculations cause common responses of the host immune system and prokaryotic component of the microbiome in Acropora palmata. PLoS One 2023; 18:e0286293. [PMID: 37228141 DOI: 10.1371/journal.pone.0286293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Accepted: 05/12/2023] [Indexed: 05/27/2023] Open
Abstract
Reef-building corals contain a complex consortium of organisms, a holobiont, which responds dynamically to disease, making pathogen identification difficult. While coral transcriptomics and microbiome communities have previously been characterized, similarities and differences in their responses to different pathogenic sources has not yet been assessed. In this study, we inoculated four genets of the Caribbean branching coral Acropora palmata with a known coral pathogen (Serratia marcescens) and white band disease. We then characterized the coral's transcriptomic and prokaryotic microbiomes' (prokaryiome) responses to the disease inoculations, as well as how these responses were affected by a short-term heat stress prior to disease inoculation. We found strong commonality in both the transcriptomic and prokaryiomes responses, regardless of disease inoculation. Differences, however, were observed between inoculated corals that either remained healthy or developed active disease signs. Transcriptomic co-expression analysis identified that corals inoculated with disease increased gene expression of immune, wound healing, and fatty acid metabolic processes. Co-abundance analysis of the prokaryiome identified sets of both healthy-and-disease-state bacteria, while co-expression analysis of the prokaryiomes' inferred metagenomic function revealed infected corals' prokaryiomes shifted from free-living to biofilm states, as well as increasing metabolic processes. The short-term heat stress did not increase disease susceptibility for any of the four genets with any of the disease inoculations, and there was only a weak effect captured in the coral hosts' transcriptomic and prokaryiomes response. Genet identity, however, was a major driver of the transcriptomic variance, primarily due to differences in baseline immune gene expression. Despite genotypic differences in baseline gene expression, we have identified a common response for components of the coral holobiont to different disease inoculations. This work has identified genes and prokaryiome members that can be focused on for future coral disease work, specifically, putative disease diagnostic tools.
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Affiliation(s)
- Benjamin D Young
- Department of Marine Biology and Ecology, Rosenstiel School of Marine, Atmospheric and Earth Science, University of Miami, Miami, Florida, United States of America
- Cooperative Institute of Marine and Atmospheric Science, Rosenstiel School of Marine Atmospheric, and Earth Science, University of Miami, Miami, Florida, United States of America
- Atlantic Oceanographic and Meteorological Laboratory, National Oceanic and Atmospheric Administration, Miami, Florida, United States of America
| | - Stephanie M Rosales
- Cooperative Institute of Marine and Atmospheric Science, Rosenstiel School of Marine Atmospheric, and Earth Science, University of Miami, Miami, Florida, United States of America
- Atlantic Oceanographic and Meteorological Laboratory, National Oceanic and Atmospheric Administration, Miami, Florida, United States of America
| | - Ian C Enochs
- Atlantic Oceanographic and Meteorological Laboratory, National Oceanic and Atmospheric Administration, Miami, Florida, United States of America
| | - Graham Kolodziej
- Cooperative Institute of Marine and Atmospheric Science, Rosenstiel School of Marine Atmospheric, and Earth Science, University of Miami, Miami, Florida, United States of America
- Atlantic Oceanographic and Meteorological Laboratory, National Oceanic and Atmospheric Administration, Miami, Florida, United States of America
| | - Nathan Formel
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, United States of America
| | - Amelia Moura
- Coral Restoration Foundation, Tavernier, Florida, United States of America
| | | | - Nikki Traylor-Knowles
- Department of Marine Biology and Ecology, Rosenstiel School of Marine, Atmospheric and Earth Science, University of Miami, Miami, Florida, United States of America
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12
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Travesso M, Missionário M, Cruz S, Calado R, Madeira D. Combined effect of marine heatwaves and light intensity on the cellular stress response and photophysiology of the leather coral Sarcophyton cf. glaucum. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 861:160460. [PMID: 36435249 DOI: 10.1016/j.scitotenv.2022.160460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 10/19/2022] [Accepted: 11/20/2022] [Indexed: 06/16/2023]
Abstract
Marine heatwaves (MHW) are threatening tropical coral reef ecosystems, leading to mass bleaching events worldwide. The combination of heat stress with high irradiance is known to shape the health and redox status of corals, but research is biased toward scleractinian corals, while much less is known on tropical symbiotic soft corals. Here, we evaluated the cellular stress response and the photophysiological performance of the soft coral Sarcophyton cf. glaucum, popularly termed as leather coral, under different global change scenarios. Corals were exposed to different light intensities (high light, low light, ∼662 and 253 μmol photons m-2 s-1) for 30 days (time-point 1) and a subsequent MHW simulation was carried out for 10 days (control 26 vs 32 °C) (time-point 2). Subsequently, corals were returned to control temperature and allowed to recover for 30 days (time-point 3). Photophysiological performance (maximum quantum yield of photosystem II (Fv/Fm), a measure of photosynthetic activity; dark-level fluorescence (F0), as a proxy of chlorophyll a content (Chl a); and zooxanthellae density) and stress biomarkers (total protein, antioxidants, lipid peroxidation, ubiquitin, and heat shock protein 70) were assessed in corals at these three time-points. Corals were especially sensitive to the combination of heat and high light stress, experiencing a decrease in their photosynthetic efficiency under these conditions. Heat stress resulted in bleaching via zooxanthellae loss while high light stress led to pigment (Chl a) loss. This species' antioxidant defenses, and protein degradation were particularly enhanced under heat stress. A recovery was clear for molecular parameters after 30 days of recovery, whereby photophysiological performance required more time to return to basal levels. We conclude that soft corals distributed along intertidal areas, where the light intensity is high, could be especially vulnerable to marine heatwave events, highlighting the need to direct conservation efforts toward these organisms.
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Affiliation(s)
- Margarida Travesso
- ECOMARE-Laboratory for Innovation and Sustainability of Marine Biological Resources, CESAM-Centre for Environmental and Marine Studies, Department of Biology, University of Aveiro, Estrada do Porto de Pesca Costeira, 3830-565 Gafanha da Nazaré, Portugal
| | - Madalena Missionário
- ECOMARE-Laboratory for Innovation and Sustainability of Marine Biological Resources, CESAM-Centre for Environmental and Marine Studies, Department of Biology, University of Aveiro, Estrada do Porto de Pesca Costeira, 3830-565 Gafanha da Nazaré, Portugal
| | - Sónia Cruz
- ECOMARE-Laboratory for Innovation and Sustainability of Marine Biological Resources, CESAM-Centre for Environmental and Marine Studies, Department of Biology, University of Aveiro, Estrada do Porto de Pesca Costeira, 3830-565 Gafanha da Nazaré, Portugal
| | - Ricardo Calado
- ECOMARE-Laboratory for Innovation and Sustainability of Marine Biological Resources, CESAM-Centre for Environmental and Marine Studies, Department of Biology, University of Aveiro, Estrada do Porto de Pesca Costeira, 3830-565 Gafanha da Nazaré, Portugal
| | - Diana Madeira
- ECOMARE-Laboratory for Innovation and Sustainability of Marine Biological Resources, CESAM-Centre for Environmental and Marine Studies, Department of Biology, University of Aveiro, Estrada do Porto de Pesca Costeira, 3830-565 Gafanha da Nazaré, Portugal.
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13
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Walker NS, Nestor V, Golbuu Y, Palumbi SR. Coral bleaching resistance variation is linked to differential mortality and skeletal growth during recovery. Evol Appl 2023; 16:504-517. [PMID: 36793702 PMCID: PMC9923480 DOI: 10.1111/eva.13500] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Revised: 09/19/2022] [Accepted: 10/12/2022] [Indexed: 11/09/2022] Open
Abstract
The prevalence of global coral bleaching has focused much attention on the possibility of interventions to increase heat resistance. However, if high heat resistance is linked to fitness tradeoffs that may disadvantage corals in other areas, then a more holistic view of heat resilience may be beneficial. In particular, overall resilience of a species to heat stress is likely to be the product of both resistance to heat and recovery from heat stress. Here, we investigate heat resistance and recovery among individual Acropora hyacinthus colonies in Palau. We divided corals into low, moderate, and high heat resistance categories based on the number of days (4-9) needed to reach significant pigmentation loss due to experimental heat stress. Afterward, we deployed corals back onto a reef in a common garden 6-month recovery experiment that monitored chlorophyll a, mortality, and skeletal growth. Heat resistance was negatively correlated with mortality during early recovery (0-1 month) but not late recovery (4-6 months), and chlorophyll a concentration recovered in heat-stressed corals by 1-month postbleaching. However, moderate-resistance corals had significantly greater skeletal growth than high-resistance corals by 4 months of recovery. High- and low-resistance corals on average did not exhibit skeletal growth within the observed recovery period. These data suggest complex tradeoffs may exist between coral heat resistance and recovery and highlight the importance of incorporating multiple aspects of resilience into future reef management programs.
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Affiliation(s)
- Nia S Walker
- Department of Biology Hopkins Marine Station of Stanford University Pacific Grove California USA.,Hawai'i Institute of Marine Biology University of Hawai'i at Mānoa Kāne'ohe Hawaii USA
| | | | | | - Stephen R Palumbi
- Department of Biology Hopkins Marine Station of Stanford University Pacific Grove California USA
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14
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Bove CB, Ingersoll MV, Davies SW. Help Me, Symbionts, You're My Only Hope: Approaches to Accelerate our Understanding of Coral Holobiont Interactions. Integr Comp Biol 2022; 62:1756-1769. [PMID: 36099871 DOI: 10.1093/icb/icac141] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 08/24/2022] [Accepted: 09/05/2022] [Indexed: 01/05/2023] Open
Abstract
Tropical corals construct the three-dimensional framework for one of the most diverse ecosystems on the planet, providing habitat to a plethora of species across taxa. However, these ecosystem engineers are facing unprecedented challenges, such as increasing disease prevalence and marine heatwaves associated with anthropogenic global change. As a result, major declines in coral cover and health are being observed across the world's oceans, often due to the breakdown of coral-associated symbioses. Here, we review the interactions between the major symbiotic partners of the coral holobiont-the cnidarian host, algae in the family Symbiodiniaceae, and the microbiome-that influence trait variation, including the molecular mechanisms that underlie symbiosis and the resulting physiological benefits of different microbial partnerships. In doing so, we highlight the current framework for the formation and maintenance of cnidarian-Symbiodiniaceae symbiosis, and the role that immunity pathways play in this relationship. We emphasize that understanding these complex interactions is challenging when you consider the vast genetic variation of the cnidarian host and algal symbiont, as well as their highly diverse microbiome, which is also an important player in coral holobiont health. Given the complex interactions between and among symbiotic partners, we propose several research directions and approaches focused on symbiosis model systems and emerging technologies that will broaden our understanding of how these partner interactions may facilitate the prediction of coral holobiont phenotype, especially under rapid environmental change.
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Affiliation(s)
- Colleen B Bove
- Department of Biology, Boston University, Boston, MA 02215, USA
| | | | - Sarah W Davies
- Department of Biology, Boston University, Boston, MA 02215, USA
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15
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Kitchen SA, Jiang D, Harii S, Satoh N, Weis VM, Shinzato C. Coral larvae suppress heat stress response during the onset of symbiosis decreasing their odds of survival. Mol Ecol 2022; 31:5813-5830. [PMID: 36168983 DOI: 10.1111/mec.16708] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 09/06/2022] [Accepted: 09/15/2022] [Indexed: 01/13/2023]
Abstract
The endosymbiosis between most corals and their photosynthetic dinoflagellate partners begins early in the host life history, when corals are larvae or juvenile polyps. The capacity of coral larvae to buffer climate-induced stress while in the process of symbiont acquisition could come with physiological trade-offs that alter behaviour, development, settlement and survivorship. Here we examined the joint effects of thermal stress and symbiosis onset on colonization dynamics, survival, metamorphosis and host gene expression of Acropora digitifera larvae. We found that thermal stress decreased symbiont colonization of hosts by 50% and symbiont density by 98.5% over 2 weeks. Temperature and colonization also influenced larval survival and metamorphosis in an additive manner, where colonized larvae fared worse or prematurely metamorphosed more often than noncolonized larvae under thermal stress. Transcriptomic responses to colonization and thermal stress treatments were largely independent, while the interaction of these treatments revealed contrasting expression profiles of genes that function in the stress response, immunity, inflammation and cell cycle regulation. The combined treatment either cancelled or lowered the magnitude of expression of heat-stress responsive genes in the presence of symbionts, revealing a physiological cost to acquiring symbionts at the larval stage with elevated temperatures. In addition, host immune suppression, a hallmark of symbiosis onset under ambient temperature, turned to immune activation under heat stress. Thus, by integrating the physical environment and biotic pressures that mediate presettlement event in corals, our results suggest that colonization may hinder larval survival and recruitment under projected climate scenarios.
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Affiliation(s)
- Sheila A Kitchen
- Department of Integrative Biology, Oregon State University, Corvallis, Oregon, USA
| | - Duo Jiang
- Statistics Department, Oregon State University, Corvallis, Oregon, USA
| | - Saki Harii
- Tropical Biosphere Research Center, University of the Ryukyus, Okinawa, Japan
| | - Noriyuki Satoh
- Marine Genomics Unit, Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan
| | - Virginia M Weis
- Department of Integrative Biology, Oregon State University, Corvallis, Oregon, USA
| | - Chuya Shinzato
- Marine Genomics Unit, Okinawa Institute of Science and Technology Graduate University, Okinawa, Japan
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16
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Alderdice R, Perna G, Cárdenas A, Hume BCC, Wolf M, Kühl M, Pernice M, Suggett DJ, Voolstra CR. Deoxygenation lowers the thermal threshold of coral bleaching. Sci Rep 2022; 12:18273. [PMID: 36316371 PMCID: PMC9622859 DOI: 10.1038/s41598-022-22604-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Accepted: 10/17/2022] [Indexed: 12/02/2022] Open
Abstract
Exposure to deoxygenation from climate warming and pollution is emerging as a contributing factor of coral bleaching and mortality. However, the combined effects of heating and deoxygenation on bleaching susceptibility remain unknown. Here, we employed short-term thermal stress assays to show that deoxygenated seawater can lower the thermal limit of an Acropora coral by as much as 1 °C or 0.4 °C based on bleaching index scores or dark-acclimated photosynthetic efficiencies, respectively. Using RNA-Seq, we show similar stress responses to heat with and without deoxygenated seawater, both activating putative key genes of the hypoxia-inducible factor response system indicative of cellular hypoxia. We also detect distinct deoxygenation responses, including a disruption of O2-dependent photo-reception/-protection, redox status, and activation of an immune response prior to the onset of bleaching. Thus, corals are even more vulnerable when faced with heat stress in deoxygenated waters. This highlights the need to integrate dissolved O2 measurements into global monitoring programs of coral reefs.
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Affiliation(s)
- Rachel Alderdice
- Climate Change Cluster, Faculty of Science, University of Technology Sydney, Ultimo, NSW, 2007, Australia.
- Department of Biology, University of Konstanz, 78457, Konstanz, Germany.
| | - Gabriela Perna
- Department of Biology, University of Konstanz, 78457, Konstanz, Germany
| | - Anny Cárdenas
- Department of Biology, University of Konstanz, 78457, Konstanz, Germany
| | - Benjamin C C Hume
- Department of Biology, University of Konstanz, 78457, Konstanz, Germany
| | - Martin Wolf
- Department of Biology, University of Konstanz, 78457, Konstanz, Germany
| | - Michael Kühl
- Marine Biology Section, Department of Biology, University of Copenhagen, Strandpromenaden 5, 3000, Helsingør, Denmark
| | - Mathieu Pernice
- Climate Change Cluster, Faculty of Science, University of Technology Sydney, Ultimo, NSW, 2007, Australia
| | - David J Suggett
- Climate Change Cluster, Faculty of Science, University of Technology Sydney, Ultimo, NSW, 2007, Australia
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17
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Salazar OR, N. Arun P, Cui G, Bay LK, van Oppen MJH, Webster NS, Aranda M. The coral Acropora loripes genome reveals an alternative pathway for cysteine biosynthesis in animals. SCIENCE ADVANCES 2022; 8:eabq0304. [PMID: 36149959 PMCID: PMC9506716 DOI: 10.1126/sciadv.abq0304] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 08/10/2022] [Indexed: 05/28/2023]
Abstract
The metabolic capabilities of animals have been derived from well-studied model organisms and are generally considered to be well understood. In animals, cysteine is an important amino acid thought to be exclusively synthesized through the transsulfuration pathway. Corals of the genus Acropora have lost cystathionine β-synthase, a key enzyme of the transsulfuration pathway, and it was proposed that Acropora relies on the symbiosis with dinoflagellates of the family Symbiodiniaceae for the acquisition of cysteine. Here, we identify the existence of an alternative pathway for cysteine biosynthesis in animals through the analysis of the genome of the coral Acropora loripes. We demonstrate that these coral proteins are functional and synthesize cysteine in vivo, exhibiting previously unrecognized metabolic capabilities of animals. This pathway is also present in most animals but absent in mammals, arthropods, and nematodes, precisely the groups where most of the animal model organisms belong to, highlighting the risks of generalizing findings from model organisms.
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Affiliation(s)
- Octavio R. Salazar
- Marine Science Program, Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Kingdom of Saudi Arabia
- Red Sea Research Center, King Abdullah University of Science and Technology, Thuwal, Kingdom of Saudi Arabia
| | - Prasanna N. Arun
- Marine Science Program, Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Kingdom of Saudi Arabia
- Red Sea Research Center, King Abdullah University of Science and Technology, Thuwal, Kingdom of Saudi Arabia
| | - Guoxin Cui
- Marine Science Program, Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Kingdom of Saudi Arabia
- Red Sea Research Center, King Abdullah University of Science and Technology, Thuwal, Kingdom of Saudi Arabia
| | - Line K. Bay
- Australian Institute of Marine Science, Townsville, Queensland, Australia
- AIMS@JCU, Division of Research and Innovation, James Cook University, Townsville, Australia
| | - Madeleine J. H. van Oppen
- Australian Institute of Marine Science, Townsville, Queensland, Australia
- School of BioSciences, University of Melbourne, Parkville, Victoria 3010, Australia
| | - Nicole S. Webster
- Australian Institute of Marine Science, Townsville, Queensland, Australia
- Australian Centre for Ecogenomics, University of Queensland, St Lucia, Australia
- Australian Antarctic Division, Department of Agriculture, Water and the Environment, Kingston, Australia
| | - Manuel Aranda
- Marine Science Program, Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Kingdom of Saudi Arabia
- Red Sea Research Center, King Abdullah University of Science and Technology, Thuwal, Kingdom of Saudi Arabia
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18
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Burgess BJ, Jackson MC, Murrell DJ. Are experiment sample sizes adequate to detect biologically important interactions between multiple stressors? Ecol Evol 2022. [PMID: 36177120 DOI: 10.1101/2021.07.21.453207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/14/2023] Open
Abstract
As most ecosystems are being challenged by multiple, co-occurring stressors, an important challenge is to understand and predict how stressors interact to affect biological responses. A popular approach is to design factorial experiments that measure biological responses to pairs of stressors and compare the observed response to a null model expectation. Unfortunately, we believe experiment sample sizes are inadequate to detect most non-null stressor interaction responses, greatly hindering progress. Using both real and simulated data, we show sample sizes typical of many experiments (<6) can (i) only detect very large deviations from the additive null model, implying many important non-null stressor-pair interactions are being missed, and (ii) potentially lead to mostly statistical outliers being reported. Computer code that simulates data under either additive or multiplicative null models is provided to estimate statistical power for user-defined responses and sample sizes, and we recommend this is used to aid experimental design and interpretation of results. We suspect that most experiments may require 20 or more replicates per treatment to have adequate power to detect nonadditive. However, estimates of power need to be made while considering the smallest interaction of interest, i.e., the lower limit for a biologically important interaction, which is likely to be system-specific, meaning a general guide is unavailable. We discuss ways in which the smallest interaction of interest can be chosen, and how sample sizes can be increased. Our main analyses relate to the additive null model, but we show similar problems occur for the multiplicative null model, and we encourage similar investigations into the statistical power of other null models and inference methods. Without knowledge of the detection abilities of the statistical tools at hand or the definition of the smallest meaningful interaction, we will undoubtedly continue to miss important ecosystem stressor interactions.
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Affiliation(s)
- Benjamin J Burgess
- Centre for Biodiversity and Environment Research, Department of Genetics, Evolution and Environment University College London London UK
- RTI Health Solutions Didsbury, Manchester UK
| | | | - David J Murrell
- Centre for Biodiversity and Environment Research, Department of Genetics, Evolution and Environment University College London London UK
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19
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Burgess BJ, Jackson MC, Murrell DJ. Are experiment sample sizes adequate to detect biologically important interactions between multiple stressors? Ecol Evol 2022; 12:e9289. [PMID: 36177120 PMCID: PMC9475135 DOI: 10.1002/ece3.9289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 08/05/2022] [Accepted: 08/22/2022] [Indexed: 11/29/2022] Open
Abstract
As most ecosystems are being challenged by multiple, co‐occurring stressors, an important challenge is to understand and predict how stressors interact to affect biological responses. A popular approach is to design factorial experiments that measure biological responses to pairs of stressors and compare the observed response to a null model expectation. Unfortunately, we believe experiment sample sizes are inadequate to detect most non‐null stressor interaction responses, greatly hindering progress. Using both real and simulated data, we show sample sizes typical of many experiments (<6) can (i) only detect very large deviations from the additive null model, implying many important non‐null stressor‐pair interactions are being missed, and (ii) potentially lead to mostly statistical outliers being reported. Computer code that simulates data under either additive or multiplicative null models is provided to estimate statistical power for user‐defined responses and sample sizes, and we recommend this is used to aid experimental design and interpretation of results. We suspect that most experiments may require 20 or more replicates per treatment to have adequate power to detect nonadditive. However, estimates of power need to be made while considering the smallest interaction of interest, i.e., the lower limit for a biologically important interaction, which is likely to be system‐specific, meaning a general guide is unavailable. We discuss ways in which the smallest interaction of interest can be chosen, and how sample sizes can be increased. Our main analyses relate to the additive null model, but we show similar problems occur for the multiplicative null model, and we encourage similar investigations into the statistical power of other null models and inference methods. Without knowledge of the detection abilities of the statistical tools at hand or the definition of the smallest meaningful interaction, we will undoubtedly continue to miss important ecosystem stressor interactions.
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Affiliation(s)
- Benjamin J Burgess
- Centre for Biodiversity and Environment Research, Department of Genetics, Evolution and Environment University College London London UK.,RTI Health Solutions Didsbury, Manchester UK
| | | | - David J Murrell
- Centre for Biodiversity and Environment Research, Department of Genetics, Evolution and Environment University College London London UK
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20
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Ip JCH, Zhang Y, Xie JY, Yeung YH, Qiu JW. Comparative transcriptomics of two coral holobionts collected during the 2017 El Niño heat wave reveal differential stress response mechanisms. MARINE POLLUTION BULLETIN 2022; 182:114017. [PMID: 35963227 DOI: 10.1016/j.marpolbul.2022.114017] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 07/28/2022] [Accepted: 07/31/2022] [Indexed: 06/15/2023]
Abstract
Although coral species exhibit differential susceptibility to stressors, little is known about the underlying molecular mechanisms. Here we compared scleractinian corals Montipora peltiformis and Platygyra carnosa collected during the 2017 El Niño heat wave. Zooxanthellae density and chlorophyll a content declined and increased substantially during and after heat stress event, respective. However, the magnitude of change was larger in M. peltiformis. Transcriptome analysis showed that heat-stressed corals corresponded to metabolic depression and catabolism of amino acids in both hosts which might promote their survival. However, only M. peltiformis has developed the bleached coral phenotype with corresponding strong stress- and immune-related responses in the host and symbiont, and strong suppression of photosynthesis-related genes in the symbiont. Overall, our study reveals differences among species in the homeostatic capacity to prevent the development of the bleached phenotype under environmental stressors, eventually determining their likelihood of survival in the warming ocean.
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Affiliation(s)
- Jack Chi-Ho Ip
- Department of Biology, Hong Kong Baptist University, Hong Kong, China; Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China; HKBU Institute of Research and Continuing Education, Virtual University Park, Shenzhen, China
| | - Yanjie Zhang
- School of Life Sciences, Hainan University, Haikou, China.
| | - James Y Xie
- Department of Biology, Hong Kong Baptist University, Hong Kong, China
| | - Yip Hung Yeung
- Department of Biology, Hong Kong Baptist University, Hong Kong, China
| | - Jian-Wen Qiu
- Department of Biology, Hong Kong Baptist University, Hong Kong, China; Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China; HKBU Institute of Research and Continuing Education, Virtual University Park, Shenzhen, China.
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21
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Expression plasticity regulates intraspecific variation in the acclimatization potential of a reef-building coral. Nat Commun 2022; 13:4790. [PMID: 35970904 PMCID: PMC9378650 DOI: 10.1038/s41467-022-32452-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Accepted: 08/01/2022] [Indexed: 11/09/2022] Open
Abstract
Phenotypic plasticity is an important ecological and evolutionary response for organisms experiencing environmental change, but the ubiquity of this capacity within coral species and across symbiont communities is unknown. We exposed ten genotypes of the reef-building coral Montipora capitata with divergent symbiont communities to four thermal pre-exposure profiles and quantified gene expression before stress testing 4 months later. Here we show two pre-exposure profiles significantly enhance thermal tolerance despite broadly different expression patterns and substantial variation in acclimatization potential based on coral genotype. There was no relationship between a genotype’s basal thermal sensitivity and ability to acquire heat tolerance, including in corals harboring naturally tolerant symbionts, which illustrates the potential for additive improvements in coral response to climate change. These results represent durable improvements from short-term stress hardening of reef-building corals and substantial cryptic complexity in the capacity for plasticity. Phenotypic plasticity is an important response for organisms experiencing climate change. Here, Drury et al. show that stress-hardening can produce durable improvements in coral thermal tolerance, masking substantial variation between individuals.
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22
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The role of gene expression and symbiosis in reef-building coral acquired heat tolerance. Nat Commun 2022; 13:4513. [PMID: 35922443 PMCID: PMC9349291 DOI: 10.1038/s41467-022-32217-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Accepted: 07/19/2022] [Indexed: 11/13/2022] Open
Abstract
Predicting how reef-building corals will respond to accelerating ocean warming caused by climate change requires knowledge of how acclimation and symbiosis modulate heat tolerance in coral early life-history stages. We assayed transcriptional responses to heat in larvae and juveniles of 11 reproductive crosses of Acropora tenuis colonies along the Great Barrier Reef. Larvae produced from the warmest reef had the highest heat tolerance, although gene expression responses to heat were largely conserved by cross identity. Juvenile transcriptional responses were driven strongly by symbiosis – when in symbiosis with heat-evolved Symbiodiniaceae, hosts displayed intermediate expression between its progenitor Cladocopium and the more stress tolerant Durusdinium, indicating the acquisition of tolerance is a conserved evolutionary process in symbionts. Heat-evolved Symbiodiniaceae facilitated juvenile survival under heat stress, although host transcriptional responses to heat were positively correlated among those hosting different genera of Symbiodiniaceae. These findings reveal the relative contribution of parental environmental history as well as symbiosis establishment in coral molecular responses to heat in early life-history stages. Coral responses to ocean warming depend not only on the coral themselves, but also on their symbionts. Here, the authors experimentally assess how symbiosis and gene expression plasticity contribute to the heat stress responses of a common coral.
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23
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van Woesik R, Shlesinger T, Grottoli AG, Toonen RJ, Vega Thurber R, Warner ME, Marie Hulver A, Chapron L, McLachlan RH, Albright R, Crandall E, DeCarlo TM, Donovan MK, Eirin‐Lopez J, Harrison HB, Heron SF, Huang D, Humanes A, Krueger T, Madin JS, Manzello D, McManus LC, Matz M, Muller EM, Rodriguez‐Lanetty M, Vega‐Rodriguez M, Voolstra CR, Zaneveld J. Coral-bleaching responses to climate change across biological scales. GLOBAL CHANGE BIOLOGY 2022; 28:4229-4250. [PMID: 35475552 PMCID: PMC9545801 DOI: 10.1111/gcb.16192] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 03/28/2022] [Accepted: 03/29/2022] [Indexed: 05/26/2023]
Abstract
The global impacts of climate change are evident in every marine ecosystem. On coral reefs, mass coral bleaching and mortality have emerged as ubiquitous responses to ocean warming, yet one of the greatest challenges of this epiphenomenon is linking information across scientific disciplines and spatial and temporal scales. Here we review some of the seminal and recent coral-bleaching discoveries from an ecological, physiological, and molecular perspective. We also evaluate which data and processes can improve predictive models and provide a conceptual framework that integrates measurements across biological scales. Taking an integrative approach across biological and spatial scales, using for example hierarchical models to estimate major coral-reef processes, will not only rapidly advance coral-reef science but will also provide necessary information to guide decision-making and conservation efforts. To conserve reefs, we encourage implementing mesoscale sanctuaries (thousands of km2 ) that transcend national boundaries. Such networks of protected reefs will provide reef connectivity, through larval dispersal that transverse thermal environments, and genotypic repositories that may become essential units of selection for environmentally diverse locations. Together, multinational networks may be the best chance corals have to persist through climate change, while humanity struggles to reduce emissions of greenhouse gases to net zero.
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Affiliation(s)
- Robert van Woesik
- Institute for Global EcologyFlorida Institute of TechnologyMelbourneFloridaUSA
| | - Tom Shlesinger
- Institute for Global EcologyFlorida Institute of TechnologyMelbourneFloridaUSA
| | | | - Rob J. Toonen
- Hawai'i Institute of Marine Biology, KāneʻoheUniversity of Hawaiʻi at MānoaHonoluluHawaiiUSA
| | | | - Mark E. Warner
- School of Marine Science and PolicyUniversity of DelawareLewesDelawareUSA
| | - Ann Marie Hulver
- School of Earth SciencesThe Ohio State UniversityColumbusOhioUSA
| | - Leila Chapron
- School of Earth SciencesThe Ohio State UniversityColumbusOhioUSA
| | - Rowan H. McLachlan
- School of Earth SciencesThe Ohio State UniversityColumbusOhioUSA
- Department of MicrobiologyOregon State UniversityCorvallisOregonUSA
| | | | - Eric Crandall
- Pennsylvania State UniversityUniversity ParkPennsylvaniaUSA
| | | | - Mary K. Donovan
- Center for Global Discovery and Conservation Science and School of Geographical Sciences and Urban PlanningArizona State UniversityTempeArizonaUSA
| | - Jose Eirin‐Lopez
- Institute of EnvironmentFlorida International UniversityMiamiFloridaUSA
| | - Hugo B. Harrison
- ARC Centre of Excellence for Coral Reef StudiesJames Cook UniversityTownsvilleQueenslandAustralia
- Australian Institute of Marine ScienceTownsvilleQueenslandAustralia
| | - Scott F. Heron
- ARC Centre of Excellence for Coral Reef StudiesJames Cook UniversityTownsvilleQueenslandAustralia
- Physics and Marine Geophysical LaboratoryJames Cook UniversityTownsvilleQueenslandAustralia
| | - Danwei Huang
- Department of Biological SciencesNational University of SingaporeSingapore
| | - Adriana Humanes
- School of Natural and Environmental SciencesNewcastle UniversityNewcastle upon TyneUnited Kingdom
| | - Thomas Krueger
- Department of BiochemistryUniversity of CambridgeCambridgeUnited Kingdom
| | - Joshua S. Madin
- Hawai'i Institute of Marine Biology, KāneʻoheUniversity of Hawaiʻi at MānoaHonoluluHawaiiUSA
| | - Derek Manzello
- Center for Satellite Applications and ResearchSatellite Oceanography & Climate DivisionNational Oceanic and Atmospheric AdministrationCollege ParkMarylandUSA
| | - Lisa C. McManus
- Hawai'i Institute of Marine Biology, KāneʻoheUniversity of Hawaiʻi at MānoaHonoluluHawaiiUSA
| | - Mikhail Matz
- Department of Integrative BiologyUniversity of Texas at AustinAustinTexasUSA
| | | | | | | | | | - Jesse Zaneveld
- Division of Biological SciencesUniversity of WashingtonBothellWashingtonUSA
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24
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Drury C, Bean NK, Harris CI, Hancock JR, Huckeba J, H CM, Roach TNF, Quinn RA, Gates RD. Intrapopulation adaptive variance supports thermal tolerance in a reef-building coral. Commun Biol 2022; 5:486. [PMID: 35589814 PMCID: PMC9120509 DOI: 10.1038/s42003-022-03428-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Accepted: 04/28/2022] [Indexed: 01/05/2023] Open
Abstract
Coral holobionts are multi-species assemblages, which adds significant complexity to genotype-phenotype connections underlying ecologically important traits like coral bleaching. Small scale heterogeneity in bleaching is ubiquitous in the absence of strong environmental gradients, which provides adaptive variance needed for the long-term persistence of coral reefs. We used RAD-seq, qPCR and LC-MS/MS metabolomics to characterize host genomic variation, symbiont community and biochemical correlates in two bleaching phenotypes of the vertically transmitting coral Montipora capitata. Phenotype was driven by symbiosis state and host genetic variance. We documented 5 gene ontologies that were significantly associated with both the binary bleaching phenotype and symbiont composition, representing functions that confer a phenotype via host-symbiont interactions. We bred these corals and show that symbiont communities were broadly conserved in bulk-crosses, resulting in significantly higher survivorship under temperature stress in juveniles, but not larvae, from tolerant parents. Using a select and re-sequence approach, we document numerous gene ontologies selected by heat stress, some of which (cell signaling, antioxidant activity, pH regulation) have unique selection dynamics in larvae from thermally tolerant parents. These data show that vertically transmitting corals may have an adaptive advantage under climate change if host and symbiont variance interact to influence bleaching phenotype.
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Affiliation(s)
- Crawford Drury
- Hawai'i Institute of Marine Biology, University of Hawai'i, Kāne'ohe, HI, USA.
| | - Nina K Bean
- Hawai'i Institute of Marine Biology, University of Hawai'i, Kāne'ohe, HI, USA
| | - Casey I Harris
- Hawai'i Institute of Marine Biology, University of Hawai'i, Kāne'ohe, HI, USA
| | - Joshua R Hancock
- Hawai'i Institute of Marine Biology, University of Hawai'i, Kāne'ohe, HI, USA
| | - Joel Huckeba
- Hawai'i Institute of Marine Biology, University of Hawai'i, Kāne'ohe, HI, USA
- University of Amsterdam, Amsterdam, Netherlands
| | - Christian Martin H
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, USA
| | - Ty N F Roach
- Hawai'i Institute of Marine Biology, University of Hawai'i, Kāne'ohe, HI, USA
| | - Robert A Quinn
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, USA
| | - Ruth D Gates
- Hawai'i Institute of Marine Biology, University of Hawai'i, Kāne'ohe, HI, USA
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25
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Thomas L, Underwood JN, Rose NH, Fuller ZL, Richards ZT, Dugal L, Grimaldi CM, Cooke IR, Palumbi SR, Gilmour JP. Spatially varying selection between habitats drives physiological shifts and local adaptation in a broadcast spawning coral on a remote atoll in Western Australia. SCIENCE ADVANCES 2022; 8:eabl9185. [PMID: 35476443 PMCID: PMC9045720 DOI: 10.1126/sciadv.abl9185] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
At the Rowley Shoals in Western Australia, the prominent reef flat becomes exposed on low tide and the stagnant water in the shallow atoll lagoons heats up, creating a natural laboratory for characterizing the mechanisms of coral resilience to climate change. To explore these mechanisms in the reef coral Acropora tenuis, we collected samples from lagoon and reef slope habitats and combined whole-genome sequencing, ITS2 metabarcoding, experimental heat stress, and transcriptomics. Despite high gene flow across the atoll, we identified clear shifts in allele frequencies between habitats at relatively small linked genomic islands. Common garden heat stress assays showed corals from the lagoon to be more resistant to bleaching, and RNA sequencing revealed marked differences in baseline levels of gene expression between habitats. Our results provide new insight into the complex mechanisms of coral resilience to climate change and highlight the potential for spatially varying selection across complex coral reef seascapes to drive pronounced ecological divergence in climate-related traits.
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Affiliation(s)
- Luke Thomas
- Australian Institute of Marine Science, Indian Ocean Marine Research Centre, Crawley, Australia
- UWA Oceans Institute, Oceans Graduate School, The University of Western Australia, Crawley, Australia
- Corresponding author.
| | - Jim N. Underwood
- Australian Institute of Marine Science, Indian Ocean Marine Research Centre, Crawley, Australia
| | - Noah H. Rose
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, USA
| | - Zachary L. Fuller
- Department of Biological Sciences, Columbia University, New York, NY, USA
| | - Zoe T. Richards
- Coral Conservation and Research Group, School of Molecular and Life Sciences, Curtin University, Perth, Australia
- Collections and Research, Western Australian Museum, Welshpool, Australia
| | - Laurence Dugal
- UWA Oceans Institute, Oceans Graduate School, The University of Western Australia, Crawley, Australia
| | - Camille M. Grimaldi
- UWA Oceans Institute, Oceans Graduate School, The University of Western Australia, Crawley, Australia
| | - Ira R. Cooke
- Centre for Tropical Bioinformatics and Molecular Biology, James Cook University, Townsville, Queensland, Australia
| | - Stephen R. Palumbi
- Hopkins Marine Station, Biology Department, Stanford University, Pacific Grove, CA, USA
| | - James P. Gilmour
- Australian Institute of Marine Science, Indian Ocean Marine Research Centre, Crawley, Australia
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26
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Tanner RL, Gleason LU, Dowd WW. Environment-driven shifts in inter-individual variation and phenotypic integration within subnetworks of the mussel transcriptome and proteome. Mol Ecol 2022; 31:3112-3127. [PMID: 35363903 PMCID: PMC9321163 DOI: 10.1111/mec.16452] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 03/18/2022] [Accepted: 03/28/2022] [Indexed: 11/28/2022]
Abstract
The environment can alter the magnitude of phenotypic variation among individuals, potentially influencing evolutionary trajectories. However, environmental influences on variation are complex and remain understudied. Populations in heterogeneous environments might exhibit more variation, the amount of variation could differ between benign and stressful conditions, and/or variation might manifest in different ways among stages of the gene‐to‐protein expression cascade or among physiological functions. Here, we explore these three issues by quantifying patterns of inter‐individual variation in both transcript and protein expression levels among California mussels, Mytilus californianus Conrad. Mussels were exposed to five ecologically relevant treatments that varied in the mean and interindividual heterogeneity of body temperature. To target a diverse set of physiological functions, we assessed variation within 19 expression subnetworks, including canonical stress‐response pathways and empirically derived coexpression clusters that represent a diffuse set of cellular processes. Variation in expression was particularly pronounced in the treatments with high mean and heterogeneous body temperatures. However, with few exceptions, environment‐dependent shifts of variation in the transcriptome were not reflected in the proteome. A metric of phenotypic integration provided evidence for a greater degree of constraint on relative expression levels (i.e., stronger correlation) within expression subnetworks in benign, homogeneous environments. Our results suggest that environments that are more stressful on average – and which also tend to be more heterogeneous – can relax these expression constraints and reduce phenotypic integration within biochemical subnetworks. Context‐dependent “unmasking” of functional variation may contribute to interindividual differences in physiological phenotype and performance in stressful environments.
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Affiliation(s)
- Richelle L Tanner
- School of Biological Sciences, Washington State University, Pullman, WA, 99164, USA.,Environmental Science & Policy Program, Chapman University, Orange, CA, 92866, USA
| | - Lani U Gleason
- Department of Biological Sciences, California State University, Sacramento, Sacramento, CA, 95819, USA
| | - W Wesley Dowd
- School of Biological Sciences, Washington State University, Pullman, WA, 99164, USA
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27
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Fifer JE, Yasuda N, Yamakita T, Bove CB, Davies SW. Genetic divergence and range expansion in a western North Pacific coral. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 813:152423. [PMID: 34942242 DOI: 10.1016/j.scitotenv.2021.152423] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2021] [Revised: 12/09/2021] [Accepted: 12/11/2021] [Indexed: 06/14/2023]
Abstract
Coral poleward range expansions have recently been observed in response to warming oceans. Range expansion can lead to reduced genetic diversity and increased frequency of deleterious mutations that were rare in core populations, potentially limiting the ability for adaptation and persistence in novel environments. Successful expansions that overcome these founder effects and colonize new habitat have been attributed to multiple introductions from different sources, hybridization with native populations, or rapid adaptive evolution. Here, we investigate population genomic patterns of the reef-building coral Acropora hyacinthus along a latitudinal cline that includes a well-established range expansion front in Japan using 2b-RAD sequencing. A total of 184 coral samples were collected across seven sites spanning from ~24°N to near its northern range front at ~33°N. We uncover the presence of three cryptic lineages of A. hyacinthus, which occupy discrete reefs within this region. Only one lineage is present along the expansion front and we find evidence for its historical occupation of marginal habitats. Within this lineage we also find evidence of bottleneck pressures associated with expansion events including higher clonality, increased linkage disequilibrium, and lower genetic diversity in range edge populations compared to core populations. Asymmetric migration between populations was also detected with lower migration from edge sites. Lastly, we describe genomic signatures of local adaptation potentially attributed to lower winter temperatures experienced at the more recently expanded northern populations. Together these data illuminate the genomic consequences of range expansion in a coral and highlight how adaptation to discrete environments along expansion fronts may facilitate further range expansion in this temperate coral lineage.
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Affiliation(s)
- James E Fifer
- Department of Biology, Boston University, Boston, MA 02215, USA.
| | - Nina Yasuda
- Department of Marine Biology and Environmental Sciences, Faculty of Agriculture, University of Miyazaki, 1-1 Gakuenkibanadainishi, Miyazaki 889-2192, Japan.
| | - Takehisa Yamakita
- Marine Biodiversity and Environmental Assessment Research Center, Japan Agency for Marine-Earth Science and Technology, 2-15 Natsushimacho, Yokosuka, Kanagawa 237-0061, Japan
| | - Colleen B Bove
- Department of Biology, Boston University, Boston, MA 02215, USA
| | - Sarah W Davies
- Department of Biology, Boston University, Boston, MA 02215, USA
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28
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Dimos B, Emery M, Beavers K, MacKnight N, Brandt M, Demuth J, Mydlarz L. Adaptive Variation in Homolog Number Within Transcript Families Promotes Expression Divergence in Reef-Building Coral. Mol Ecol 2022; 31:2594-2610. [PMID: 35229964 DOI: 10.1111/mec.16414] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 02/10/2022] [Accepted: 02/22/2022] [Indexed: 11/30/2022]
Abstract
Gene expression, especially in multi-species experiments, is used to gain insight into the genetic basis of how organisms adapt and respond to changing environments. However, evolutionary processes which can influence gene expression patterns between species such as the presence of paralogs which arise from gene duplication events are rarely accounted for. Paralogous transcripts can alter the transcriptional output of a gene and thus exclusion of these transcripts can obscure important biological differences between species. To address this issue, we investigated how differences in transcript family size is associated with divergent gene expression patterns in five species of Caribbean reef-building corals. We demonstrate that transcript families that are rapidly evolving in terms of size have increased levels of expression divergence. Additionally, these rapidly evolving transcript families are enriched for multiple biological processes, with genes involved in the coral innate immune system demonstrating pronounced variation in homolog number between species. Overall, this investigation demonstrates the importance of incorporating paralogous transcripts when comparing gene expression across species by influencing both transcriptional output and the number of transcripts within biological processes. As this investigation was based on transcriptome assemblies, additional insights into the relationship between gene duplications and expression patterns will likely emergence once more genome assemblies are available for study.
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Affiliation(s)
- Bradford Dimos
- Department of Biology, University of Texas at Arlington, Arlington, TX, 76019, USA
| | - Madison Emery
- Department of Biology, University of Texas at Arlington, Arlington, TX, 76019, USA
| | - Kelsey Beavers
- Department of Biology, University of Texas at Arlington, Arlington, TX, 76019, USA
| | - Nicholas MacKnight
- Department of Biology, University of Texas at Arlington, Arlington, TX, 76019, USA
| | - Marilyn Brandt
- Center for Marine and Environmental Studies, University of the Virgin Islands, St. Thomas, US Virgin Islands, 00802, USA
| | - Jeffery Demuth
- Department of Biology, University of Texas at Arlington, Arlington, TX, 76019, USA
| | - Laura Mydlarz
- Department of Biology, University of Texas at Arlington, Arlington, TX, 76019, USA
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29
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Zhang Y, Ip JCH, Xie JY, Yeung YH, Sun Y, Qiu JW. Host-symbiont transcriptomic changes during natural bleaching and recovery in the leaf coral Pavona decussata. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 806:150656. [PMID: 34597574 DOI: 10.1016/j.scitotenv.2021.150656] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 09/24/2021] [Accepted: 09/24/2021] [Indexed: 06/13/2023]
Abstract
Coral bleaching has become a major threat to coral reefs worldwide, but for most coral species little is known about their resilience to environmental changes. We aimed to understand the gene expressional regulation underlying natural bleaching and recovery in Pavona decussata, a dominant species of scleractinian coral in the northern South China Sea. Analyzing samples collected in 2017 from the field revealed distinct zooxanthellae density, chlorophyll a concentration and transcriptomic signatures corresponding to changes in health conditions of the coral holobiont. In the host, normal-looking tissues of partially bleached colonies were frontloaded with stress responsive genes, as indicated by upregulation of immune defense, response to endoplasmic reticulum, and oxidative stress genes. Bleaching was characterized by upregulation of apoptosis-related genes which could cause a reduction in algal symbionts, and downregulation of genes involved in stress responses and metabolic processes. The transcription factors stat5b and irf1 played key roles in bleaching by regulating immune and apoptosis pathways. Recovery from bleaching was characterized by enrichment of pathways involved in mitosis, DNA replication, and recombination for tissue repairing, as well as restoration of energy and metabolism. In the symbionts, bleaching corresponded to imbalance in photosystems I and II activities which enhanced oxidative stress and limited energy production and nutrient assimilation. Overall, our study revealed distinct gene expressional profiles and regulation in the different phases of the bleaching and recovery process, and provided new insight into the molecular mechanisms underlying the holobiont's resilience that may determine the species' fate in response to global and regional environmental changes.
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Affiliation(s)
- Yanjie Zhang
- Department of Biology, Hong Kong Branch of Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Hong Kong Baptist University, Hong Kong, China; Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China; State Key Laboratory of Environmental and Biological Analysis, Hong Kong Baptist University, Hong Kong, China
| | - Jack Chi-Ho Ip
- Department of Biology, Hong Kong Branch of Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Hong Kong Baptist University, Hong Kong, China
| | - James Y Xie
- Department of Biology, Hong Kong Branch of Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Hong Kong Baptist University, Hong Kong, China
| | - Yip Hung Yeung
- Department of Biology, Hong Kong Branch of Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Hong Kong Baptist University, Hong Kong, China
| | - Yanan Sun
- Department of Biology, Hong Kong Branch of Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Hong Kong Baptist University, Hong Kong, China
| | - Jian-Wen Qiu
- Department of Biology, Hong Kong Branch of Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Hong Kong Baptist University, Hong Kong, China; Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China; State Key Laboratory of Environmental and Biological Analysis, Hong Kong Baptist University, Hong Kong, China.
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30
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Vargas S, Zimmer T, Conci N, Lehmann M, Wörheide G. Transcriptional response of the calcification and stress response toolkits in an octocoral under heat and pH stress. Mol Ecol 2021; 31:798-810. [PMID: 34748669 DOI: 10.1111/mec.16266] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 10/22/2021] [Accepted: 10/27/2021] [Indexed: 10/19/2022]
Abstract
Up to one-third of all described marine species inhabit coral reefs, but the future of these hyperdiverse ecosystems is insecure due to local and global threats, such as overfishing, eutrophication, ocean warming and acidification. Although these impacts are expected to have a net detrimental effect on reefs, it has been shown that some organisms such as octocorals may remain unaffected, or benefit from, anthropogenically induced environmental change, and may replace stony corals in future reefs. Despite their potential importance in future shallow-water coastal environments, the molecular mechanisms leading to the resilience to anthropogenically induced stress observed in octocorals remain unknown. Here, we use manipulative experiments, proteomics and transcriptomics to show that the molecular toolkit used by Pinnigorgia flava, a common Indo-Pacific gorgonian octocoral, to deposit its calcium carbonate skeleton is resilient to heat and seawater acidification stress. Sublethal heat stress triggered a stress response in P. flava but did not affect the expression of 27 transcripts encoding skeletal organic matrix (SOM) proteins. Exposure to seawater acidification did not cause a stress response but triggered the downregulation of many transcripts, including an osteonidogen homologue present in the SOM. The observed transcriptional decoupling of the skeletogenic and stress-response toolkits provides insights into the mechanisms of resilience to anthropogenically driven environmental change observed in octocorals.
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Affiliation(s)
- Sergio Vargas
- Department of Earth and Environmental Sciences, Paleontology & Geobiology, Ludwig-Maximilians-Universität München, München, Germany
| | - Thorsten Zimmer
- Department of Earth and Environmental Sciences, Paleontology & Geobiology, Ludwig-Maximilians-Universität München, München, Germany
| | - Nicola Conci
- Department of Earth and Environmental Sciences, Paleontology & Geobiology, Ludwig-Maximilians-Universität München, München, Germany
| | - Martin Lehmann
- Plant Molecular Biology, Faculty of Biology, Ludwig-Maximilians-Universität München, Planegg-Martinsried, Germany
| | - Gert Wörheide
- Department of Earth and Environmental Sciences, Paleontology & Geobiology, Ludwig-Maximilians-Universität München, München, Germany.,GeoBio-Center, Ludwig-Maximilians-Universität München, München, Germany.,SNSB-Bayerische Staatssammlung für Paläontologie und Geologie, München, Germany
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31
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Abbott E, Dixon G, Matz M. Shuffling between Cladocopium and Durusdinium extensively modifies the physiology of each symbiont without stressing the coral host. Mol Ecol 2021; 30:6585-6595. [PMID: 34551161 DOI: 10.1111/mec.16190] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 08/23/2021] [Accepted: 09/10/2021] [Indexed: 12/28/2022]
Abstract
As sea surface temperatures increase, many coral species that used to harbour symbionts of the genus Cladocopium have become colonized with the thermally tolerant genus, Durusdinium. Here, we asked how gene expression in the symbionts of one genus changes depending on the abundance of another symbiont genus within the same coral host, and what effect this interaction has on the host. Symbiont gene expression was overwhelmingly driven by whether the genus was the minority or the majority within the host, which affected 79% (Durusdinium) and 96% (Cladocopium) of all genes. Particularly strong effects in both genera were observed for photosynthesis components (upregulated in the minority state) and proteins putatively associated with cell motility (upregulated in the majority state). Importantly, there was no distinct gene expression signature associated with the mixed symbiosis state when both genera were represented in comparable proportions within the host, which could lead to more intense competition. The mixed symbiosis was also not associated with elevated host stress: in fact, after heat treatment, stress signatures were the lowest in mixed-symbiosis corals compared to both Cladocopium- and Durusdinium-dominated corals. In conclusion, during shuffling between Cladocopium and Durusdinium both symbiont genera go through extensive and largely reciprocal physiological transitions, but there is no evidence of intensifying antagonistic interactions that are detrimental to the host. Unless the mixed-symbiosis corals in this study are not representative of the typical transition between Cladocopium and Durusdinium, the process of shuffling from one symbiont genus to another appears to be cost-free for the coral host, and even appears to be associated with lower stress susceptibility. This raises optimism for the future corals, which will probably have to rely on symbiont shuffling more and more to withstand environmental challenges.
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Affiliation(s)
- Evelyn Abbott
- Department of Integrative Biology, University of Texas at Austin, Austin, Texas, USA
| | - Groves Dixon
- Department of Integrative Biology, University of Texas at Austin, Austin, Texas, USA
| | - Mikhail Matz
- Department of Integrative Biology, University of Texas at Austin, Austin, Texas, USA
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32
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Strohecker J, Golladay J, Paramo M, Paramo M, El Rahmany W, Blackstone NW. Reactive Oxygen Species and the Stress Response in Octocorals. Physiol Biochem Zool 2021; 94:394-410. [PMID: 34542375 DOI: 10.1086/716857] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AbstractReactive oxygen species (ROS) may damage cellular components but may also contribute to signaling that mitigates damage. In this context, the role of ROS in the stress response that leads to coral bleaching was investigated in three series of experiments with octocorals Sarcothelia sp. and Sympodium sp. Using video and fluorescent microscopy, the first experiments examined ROS and symbiont migration. Colonies mildly stressed with increased temperature and light showed increases in both ROS and numbers of migrating symbionts compared with stress-free controls. Symbionts migrating in the gastrovascular lumen may escape programmed cell death and provide a reservoir of healthy symbionts once conditions return to normal. In the second series of experiments, colonies were mildly stressed with elevated temperature and light. During stress, treated colonies were incubated in seawater enriched with two concentrations of bicarbonate (1 and 3 mmol/L), while controls were incubated in normal seawater. Bicarbonate enrichment provides additional carbon for photosynthesis and at some concentrations diminished the ROS emissions of stressed colonies of Sympodium sp. and Sarcothelia sp. In all experiments, the latter species tended to exhibit more ROS. Sympodium sp. contains Cladocopium sp. symbionts, which are less tolerant of stress, while Sarcothelia sp. contains the more resistant Durusdinium sp. Indeed, in direct comparisons, Sarcothelia sp. experienced higher levels of ROS under stress-free conditions and thus is conditioned to endure the stress associated with bleaching. Generally, ROS levels provide important insight into the cnidarian stress response and should be measured more often in studies of this response.
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33
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Wuitchik DM, Almanzar A, Benson BE, Brennan S, Chavez JD, Liesegang MB, Reavis JL, Reyes CL, Schniedewind MK, Trumble IF, Davies SW. Title: Characterizing environmental stress responses of aposymbiotic Astrangia poculata to divergent thermal challenges. Mol Ecol 2021; 30:5064-5079. [PMID: 34379848 DOI: 10.1111/mec.16108] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Revised: 07/13/2021] [Accepted: 07/28/2021] [Indexed: 11/29/2022]
Abstract
Anthropogenic climate change threatens corals globally and both high and low temperatures are known to induce coral bleaching. However, coral stress responses across wide thermal breadths remain understudied. Disentangling the role of symbiosis on the stress response in obligately symbiotic corals is challenging because this response is inherently coupled with nutritional stress. Here, we leverage aposymbiotic colonies of the facultatively symbiotic coral, Astrangia poculata, which lives naturally with and without its algal symbionts, to examine how broad thermal challenges influence coral hosts in the absence of symbiosis. A. poculata were collected from their northern range limit and thermally challenged in two independent 16-day common garden experiments (heat and cold challenge) and behavioral responses to food stimuli and genome-wide gene expression profiling (TagSeq) were performed. Both thermal challenges elicited significant reductions in polyp extension. However, there were five times as many differentially expressed genes (DEGs) under cold challenge compared to heat challenge. Despite an overall stronger response to cold challenge, there was significant overlap in DEGs between thermal challenges. We contrasted these responses to a previously identified module of genes associated with the environmental stress response (ESR) in tropical reef-building corals. Cold challenged corals exhibited a pattern consistent with more severe stressors while the heat challenge response was consistent with lower intensity stressors. Given that these responses were observed in aposymbiotic colonies, many genes previously implicated in ESRs in tropical symbiotic species may represent the coral host's stress response in or out of symbiosis.
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Affiliation(s)
- D M Wuitchik
- Department of Biology, Boston University, Boston, MA, USA
| | - A Almanzar
- Department of Biology, Boston University, Boston, MA, USA
| | - B E Benson
- Department of Biology, Boston University, Boston, MA, USA
| | - S Brennan
- Department of Biology, Boston University, Boston, MA, USA
| | - J D Chavez
- Department of Biology, Boston University, Boston, MA, USA
| | - M B Liesegang
- Department of Biology, Boston University, Boston, MA, USA.,Scripps Institution of Oceanography, University of California San Diego, San Diego, CA, USA
| | - J L Reavis
- Department of Biology, Boston University, Boston, MA, USA
| | - C L Reyes
- Department of Biology, Boston University, Boston, MA, USA
| | | | - I F Trumble
- Department of Biology, Boston University, Boston, MA, USA
| | - S W Davies
- Department of Biology, Boston University, Boston, MA, USA
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34
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Santoro EP, Borges RM, Espinoza JL, Freire M, Messias CSMA, Villela HDM, Pereira LM, Vilela CLS, Rosado JG, Cardoso PM, Rosado PM, Assis JM, Duarte GAS, Perna G, Rosado AS, Macrae A, Dupont CL, Nelson KE, Sweet MJ, Voolstra CR, Peixoto RS. Coral microbiome manipulation elicits metabolic and genetic restructuring to mitigate heat stress and evade mortality. SCIENCE ADVANCES 2021; 7:7/33/eabg3088. [PMID: 34389536 PMCID: PMC8363143 DOI: 10.1126/sciadv.abg3088] [Citation(s) in RCA: 85] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 06/24/2021] [Indexed: 05/03/2023]
Abstract
Beneficial microorganisms for corals (BMCs) ameliorate environmental stress, but whether they can prevent mortality and the underlying host response mechanisms remains elusive. Here, we conducted omics analyses on the coral Mussismilia hispida exposed to bleaching conditions in a long-term mesocosm experiment and inoculated with a selected BMC consortium or a saline solution placebo. All corals were affected by heat stress, but the observed "post-heat stress disorder" was mitigated by BMCs, signified by patterns of dimethylsulfoniopropionate degradation, lipid maintenance, and coral host transcriptional reprogramming of cellular restructuration, repair, stress protection, and immune genes, concomitant with a 40% survival rate increase and stable photosynthetic performance by the endosymbiotic algae. This study provides insights into the responses that underlie probiotic host manipulation. We demonstrate that BMCs trigger a dynamic microbiome restructuring process that instigates genetic and metabolic alterations in the coral host that eventually mitigate coral bleaching and mortality.
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Affiliation(s)
- Erika P Santoro
- Institute of Microbiology, Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
| | - Ricardo M Borges
- Walter Mors Institute of Research on Natural Products, Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
| | - Josh L Espinoza
- Department of Genomic Medicine and Infectious Diseases, J. Craig Venter Institute, La Jolla, CA, USA
- Applied Sciences, Durban University of Technology, Durban, South Africa
| | - Marcelo Freire
- Department of Genomic Medicine and Infectious Diseases, J. Craig Venter Institute, La Jolla, CA, USA
- Department of Infectious Diseases and Global Health, School of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Camila S M A Messias
- Institute of Microbiology, Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
| | - Helena D M Villela
- Institute of Microbiology, Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
| | - Leandro M Pereira
- Institute of Microbiology, Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
| | - Caren L S Vilela
- Institute of Microbiology, Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
| | - João G Rosado
- Institute of Microbiology, Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
- Red Sea Research Center (RSRC), Division of Biological and Environmental Science and Engineering (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Pedro M Cardoso
- Institute of Microbiology, Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
| | - Phillipe M Rosado
- Institute of Microbiology, Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
| | - Juliana M Assis
- Institute of Microbiology, Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
| | - Gustavo A S Duarte
- Institute of Microbiology, Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
| | - Gabriela Perna
- Red Sea Research Center (RSRC), Division of Biological and Environmental Science and Engineering (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
- Department of Biology, University of Konstanz, Konstanz 78457, Germany
| | - Alexandre S Rosado
- Institute of Microbiology, Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
- Division of Biological and Environmental Science and Engineering (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Andrew Macrae
- Institute of Microbiology, Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
| | - Christopher L Dupont
- Department of Genomic Medicine and Infectious Diseases, J. Craig Venter Institute, La Jolla, CA, USA
| | - Karen E Nelson
- Department of Genomic Medicine and Infectious Diseases, J. Craig Venter Institute, La Jolla, CA, USA
| | - Michael J Sweet
- Aquatic Research Facility, Environmental Sustainability Research Centre, University of Derby, Derby, UK
| | - Christian R Voolstra
- Red Sea Research Center (RSRC), Division of Biological and Environmental Science and Engineering (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
- Department of Biology, University of Konstanz, Konstanz 78457, Germany
| | - Raquel S Peixoto
- Institute of Microbiology, Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil.
- Red Sea Research Center (RSRC), Division of Biological and Environmental Science and Engineering (BESE), King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
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35
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Chromatin Dynamics and Gene Expression Response to Heat Exposure in Field-Conditioned versus Laboratory-Cultured Nematostella vectensis. Int J Mol Sci 2021; 22:ijms22147454. [PMID: 34299075 PMCID: PMC8303994 DOI: 10.3390/ijms22147454] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 07/05/2021] [Accepted: 07/08/2021] [Indexed: 12/19/2022] Open
Abstract
Organisms’ survival is associated with the ability to respond to natural or anthropogenic environmental stressors. Frequently, these responses involve changes in gene regulation and expression, consequently altering physiology, development, or behavior. Here, we present modifications in response to heat exposure that mimics extreme summertime field conditions of lab-cultured and field-conditioned Nematostella vectensis. Using ATAC-seq and RNA-seq data, we found that field-conditioned animals had a more concentrated reaction to short-term thermal stress, expressed as enrichment of the DNA repair mechanism pathway. By contrast, lab animals had a more diffuse reaction that involved a larger number of differentially expressed genes and enriched pathways, including amino acid metabolism. Our results demonstrate that pre-conditioning affects the ability to respond efficiently to heat exposure in terms of both chromatin accessibility and gene expression and reinforces the importance of experimentally addressing ecological questions in the field.
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36
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Metabolomic signatures of coral bleaching history. Nat Ecol Evol 2021; 5:495-503. [PMID: 33558733 DOI: 10.1038/s41559-020-01388-7] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Accepted: 12/18/2020] [Indexed: 12/13/2022]
Abstract
Coral bleaching has a profound impact on the health and function of reef ecosystems, but the metabolomic effects of coral bleaching are largely uncharacterized. Here, untargeted metabolomics was used to analyse pairs of adjacent Montipora capitata corals that had contrasting bleaching phenotypes during a severe bleaching event in 2015. When these same corals were sampled four years later while visually healthy, there was a strong metabolomic signature of bleaching history. This was primarily driven by betaine lipids from the symbiont, where corals that did not bleach were enriched in saturated lyso-betaine lipids. Immune modulator molecules were also altered by bleaching history in both the coral host and the algal symbiont, suggesting a shared role in partner choice and bleaching response. Metabolomics from a separate set of validation corals was able to predict the bleaching phenotype with 100% accuracy. Experimental temperature stress induced phenotype-specific responses, which magnified differences between historical bleaching phenotypes. These findings indicate that natural bleaching susceptibility is manifested in the biochemistry of both the coral animal and its algal symbiont. This metabolome difference is stable through time and results in different physiological responses to temperature stress. This work provides insight into the biochemical mechanisms of coral bleaching and presents a valuable new tool for resilience-based reef restoration.
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37
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Fifer J, Bentlage B, Lemer S, Fujimura AG, Sweet M, Raymundo LJ. Going with the flow: How corals in high-flow environments can beat the heat. Mol Ecol 2021; 30:2009-2024. [PMID: 33655552 DOI: 10.1111/mec.15869] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2019] [Revised: 01/28/2021] [Accepted: 02/16/2021] [Indexed: 12/18/2022]
Abstract
Coral reefs are experiencing unprecedented declines in health on a global scale leading to severe reductions in coral cover. One major cause of this decline is increasing sea surface temperature. However, conspecific colonies separated by even small spatial distances appear to show varying responses to this global stressor. One factor contributing to differential responses to heat stress is variability in the coral's micro-environment, such as the amount of water flow a coral experiences. High flow provides corals with a variety of health benefits, including heat stress mitigation. Here, we investigate how water flow affects coral gene expression and provides resilience to increasing temperatures. We examined host and photosymbiont gene expression of Acropora cf. pulchra colonies in discrete in situ flow environments during a natural bleaching event. In addition, we conducted controlled ex situ tank experiments where we exposed A. cf. pulchra to different flow regimes and acute heat stress. Notably, we observed distinct flow-driven transcriptomic signatures related to energy expenditure, growth, heterotrophy and a healthy coral host-photosymbiont relationship. We also observed disparate transcriptomic responses during bleaching recovery between the high- and low-flow sites. Additionally, corals exposed to high flow showed "frontloading" of specific heat-stress-related genes such as heat shock proteins, antioxidant enzymes, genes involved in apoptosis regulation, innate immunity and cell adhesion. We posit that frontloading is a result of increased oxidative metabolism generated by the increased water movement. Gene frontloading may at least partially explain the observation that colonies in high-flow environments show higher survival and/or faster recovery in response to bleaching events.
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Affiliation(s)
- James Fifer
- University of Guam Marine Laboratory, UOG Station, Mangilao, GU, USA.,Department of Biology, Boston University, Boston, MA, USA
| | - Bastian Bentlage
- University of Guam Marine Laboratory, UOG Station, Mangilao, GU, USA
| | - Sarah Lemer
- University of Guam Marine Laboratory, UOG Station, Mangilao, GU, USA
| | | | - Michael Sweet
- Aquatic Research Facility, Environmental Sustainability Research Centre, University of Derby, Derby, UK
| | - Laurie J Raymundo
- University of Guam Marine Laboratory, UOG Station, Mangilao, GU, USA
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38
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Abstract
Climate-driven reef decline has prompted the development of next-generation coral conservation strategies, many of which hinge on the movement of adaptive variation across genetic and environmental gradients. This process is limited by our understanding of how genetic and genotypic drivers of coral bleaching will manifest in different environmental conditions. We reciprocally transplanted 10 genotypes of Acropora cervicornis across eight sites along a 60 km span of the Florida Reef Tract and documented significant genotype × environment interactions in bleaching response during the severe 2015 bleaching event. Performance relative to site mean was significantly different between genotypes and can be mostly explained by ensemble models of correlations with genetic markers. The high explanatory power was driven by significant enrichment of loci associated DNA repair, cell signalling and apoptosis. No genotypes performed above (or below) bleaching average at all sites, so genomic predictors can provide practitioners with 'confidence intervals' about the chance of success in novel habitats. These data have important implications for assisted gene flow and managed relocation, and their integration with traditional active restoration.
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Affiliation(s)
- Crawford Drury
- Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL 33149, USA
| | - Diego Lirman
- Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL 33149, USA
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39
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Rivera HE, Aichelman HE, Fifer JE, Kriefall NG, Wuitchik DM, Wuitchik SJS, Davies SW. A framework for understanding gene expression plasticity and its influence on stress tolerance. Mol Ecol 2021; 30:1381-1397. [PMID: 33503298 DOI: 10.1111/mec.15820] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 12/10/2020] [Accepted: 01/20/2021] [Indexed: 12/18/2022]
Abstract
Phenotypic plasticity can serve as a stepping stone towards adaptation. Recently, studies have shown that gene expression contributes to emergent stress responses such as thermal tolerance, with tolerant and susceptible populations showing distinct transcriptional profiles. However, given the dynamic nature of gene expression, interpreting transcriptomic results in a way that elucidates the functional connection between gene expression and the observed stress response is challenging. Here, we present a conceptual framework to guide interpretation of gene expression reaction norms in the context of stress tolerance. We consider the evolutionary and adaptive potential of gene expression reaction norms and discuss the influence of sampling timing, transcriptomic resilience, as well as complexities related to life history when interpreting gene expression dynamics and how these patterns relate to host tolerance. We highlight corals as a case study to demonstrate the value of this framework for non-model systems. As species face rapidly changing environmental conditions, modulating gene expression can serve as a mechanistic link from genetic and cellular processes to the physiological responses that allow organisms to thrive under novel conditions. Interpreting how or whether a species can employ gene expression plasticity to ensure short-term survival will be critical for understanding the global impacts of climate change across diverse taxa.
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Affiliation(s)
- Hanny E Rivera
- Department of Biology, Boston University, Boston, MA, USA
| | | | - James E Fifer
- Department of Biology, Boston University, Boston, MA, USA
| | | | | | - Sara J S Wuitchik
- Department of Biology, Boston University, Boston, MA, USA.,FAS Informatics, Harvard University, Cambridge, MA, USA
| | - Sarah W Davies
- Department of Biology, Boston University, Boston, MA, USA
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