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Morin M, Jönsson M, Wang CK, Craik DJ, Degnan SM, Degnan BM. Seasonal tissue-specific gene expression in wild crown-of-thorns starfish reveals reproductive and stress-related transcriptional systems. PLoS Biol 2024; 22:e3002620. [PMID: 38743647 PMCID: PMC11093393 DOI: 10.1371/journal.pbio.3002620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Accepted: 04/10/2024] [Indexed: 05/16/2024] Open
Abstract
Animals are influenced by the season, yet we know little about the changes that occur in most species throughout the year. This is particularly true in tropical marine animals that experience relatively small annual temperature and daylight changes. Like many coral reef inhabitants, the crown-of-thorns starfish (COTS), well known as a notorious consumer of corals and destroyer of coral reefs, reproduces exclusively in the summer. By comparing gene expression in 7 somatic tissues procured from wild COTS sampled on the Great Barrier Reef, we identified more than 2,000 protein-coding genes that change significantly between summer and winter. COTS genes that appear to mediate conspecific communication, including both signalling factors released into the surrounding sea water and cell surface receptors, are up-regulated in external secretory and sensory tissues in the summer, often in a sex-specific manner. Sexually dimorphic gene expression appears to be underpinned by sex- and season-specific transcription factors (TFs) and gene regulatory programs. There are over 100 TFs that are seasonally expressed, 87% of which are significantly up-regulated in the summer. Six nuclear receptors are up-regulated in all tissues in the summer, suggesting that systemic seasonal changes are hormonally controlled, as in vertebrates. Unexpectedly, there is a suite of stress-related chaperone proteins and TFs, including HIFa, ATF3, C/EBP, CREB, and NF-κB, that are uniquely and widely co-expressed in gravid females. The up-regulation of these stress proteins in the summer suggests the demands of oogenesis in this highly fecund starfish affects protein stability and turnover in somatic cells. Together, these circannual changes in gene expression provide novel insights into seasonal changes in this coral reef pest and have the potential to identify vulnerabilities for targeted biocontrol.
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Affiliation(s)
- Marie Morin
- Centre for Marine Science, School of the Environment, The University of Queensland, Brisbane, Australia
| | - Mathias Jönsson
- Centre for Marine Science, School of the Environment, The University of Queensland, Brisbane, Australia
| | - Conan K. Wang
- Institute for Molecular Bioscience, ARC Centre of Excellence for Innovations in Peptide and Protein Science, The University of Queensland, Brisbane, Australia
| | - David J. Craik
- Institute for Molecular Bioscience, ARC Centre of Excellence for Innovations in Peptide and Protein Science, The University of Queensland, Brisbane, Australia
| | - Sandie M. Degnan
- Centre for Marine Science, School of the Environment, The University of Queensland, Brisbane, Australia
| | - Bernard M. Degnan
- Centre for Marine Science, School of the Environment, The University of Queensland, Brisbane, Australia
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Pieplow CA, Furze AR, Wessel GM. A case of hermaphroditism in the gonochoristic sea urchin, Strongylocentrotus purpuratus, reveals key mechanisms of sex determination†. Biol Reprod 2023; 108:960-973. [PMID: 36943312 PMCID: PMC10266946 DOI: 10.1093/biolre/ioad036] [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: 11/22/2022] [Revised: 01/20/2023] [Accepted: 03/08/2023] [Indexed: 03/23/2023] Open
Abstract
Sea urchins are usually gonochoristic, with all of their five gonads either testes or ovaries. Here, we report an unusual case of hermaphroditism in the purple sea urchin, Strongylocentrotus purpuratus. The hermaphrodite is self-fertile, and one of the gonads is an ovotestis; it is largely an ovary with a small segment containing fully mature sperm. Molecular analysis demonstrated that each gonad producedviable gametes, and we identified for the first time a somatic sex-specific marker in this phylum: Doublesex and mab-3 related transcription factor 1 (DMRT1). This finding also enabled us to analyze the somatic tissues of the hermaphrodite, and we found that the oral tissues (including gut) were out of register with the aboral tissues (including tube feet) enabling a genetic lineage analysis. Results from this study support a genetic basis of sex determination in sea urchins, the viability of hermaphroditism, and distinguish gonad determination from somatic tissue organization in the adult.
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Affiliation(s)
- Cosmo A Pieplow
- Department of Molecular Biology and Biochemistry, Brown University, Providence, RI, USA
| | - Aidan R Furze
- Department of Molecular Biology and Biochemistry, Brown University, Providence, RI, USA
| | - Gary M Wessel
- Department of Molecular Biology and Biochemistry, Brown University, Providence, RI, USA
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Mendoza-Porras O, Nguyen TV, Shah RM, Thomas-Hall P, Bastin L, Deaker DJ, Motti CA, Byrne M, Beale DJ. Biochemical metabolomic profiling of the Crown-of-Thorns Starfish (Acanthaster): New insight into its biology for improved pest management. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 861:160525. [PMID: 36574554 DOI: 10.1016/j.scitotenv.2022.160525] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 11/20/2022] [Accepted: 11/23/2022] [Indexed: 06/17/2023]
Abstract
The Crown-of-Thorns Starfish (COTS), Acanthaster species, is a voracious coral predator that destroys coral reefs when in outbreak status. The baseline metabolite and lipid biomolecules of 10 COTS tissues, including eggs from gravid females, were investigated in this study to provide insight into their biology and identify avenues for control. Targeted and untargeted metabolite- and lipidomics-based mass spectrometry approaches were used to obtain tissue-specific metabolite and lipid profiles. Across all COTS tissues, 410 metabolites and 367 lipids were identified. Most abundant were amino acids and peptides (18.7%) and wax esters (17%). There were 262 metabolites and 192 lipids identified in COTS eggs. Wax esters were more abundant in the eggs (30%) followed by triacylglycerols (TG), amino acids, and peptides. The diversity of asterosaponins in eggs (34) was higher than in tissues (2). Several asterosaponins known to modulate sperm acrosome reaction were putatively identified, including glycoside B, asterosaponin-4 (Co-Aris III), and regularoside B (asterosaponin A). The saponins saponin A, thornasteroside A, hillaside B, and non-saponins dictyol J and axinellamine B which have been shown to possess defensive properties, were found in abundance in gonads, skin, and radial nerve tissues. Inosine and 2-hexyldecanoic acid are the most abundant metabolites in tissues and eggs. As a secondary metabolite of purine degradation, inosine plays an important role in purine biosynthesis, while 2-hexyldecanoic acid is known to suppress side-chain crystallization during the synthesis of amphiphilic macromolecules (i.e., phospholipids). These significant spatial changes in metabolite, lipid, and asterosaponin profiles enabled unique insights into key biological tissue-specific processes that could be manipulated to better control COTS populations. Our findings highlight COTS as a novel source of molecules with therapeutic and cosmetic properties (ceramides, sphingolipids, carnosine, and inosine). These outcomes will be highly relevant for the development of strategies for COTS management including chemotaxis-based biocontrol and exploitation of COTS carcasses for the extraction of commercial molecules.
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Affiliation(s)
- Omar Mendoza-Porras
- Agriculture and Food, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Queensland Bioscience Precinct, St Lucia, QLD 4067, Australia
| | - Thao V Nguyen
- Land and Water, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Ecosciences Precinct, Dutton Park, QLD 4102, Australia
| | - Rohan M Shah
- Land and Water, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Ecosciences Precinct, Dutton Park, QLD 4102, Australia
| | - Peter Thomas-Hall
- Australian Institute of Marine Science (AIMS), Townsville, QLD 4810, Australia
| | - Lee Bastin
- Australian Institute of Marine Science (AIMS), Townsville, QLD 4810, Australia
| | - Dione J Deaker
- Marine Studies Institute, School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW 2006, Australia
| | - Cherie A Motti
- Australian Institute of Marine Science (AIMS), Townsville, QLD 4810, Australia
| | - Maria Byrne
- Marine Studies Institute, School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW 2006, Australia
| | - David J Beale
- Land and Water, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Ecosciences Precinct, Dutton Park, QLD 4102, Australia.
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Jönsson M, Morin M, Wang CK, Craik DJ, Degnan SM, Degnan BM. Sex-specific expression of pheromones and other signals in gravid starfish. BMC Biol 2022; 20:288. [PMID: 36528687 PMCID: PMC9759900 DOI: 10.1186/s12915-022-01491-0] [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: 04/13/2022] [Accepted: 12/01/2022] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Many echinoderms form seasonal aggregations prior to spawning. In some fecund species, a spawning event can lead to population outbreaks with detrimental ecosystem impacts. For instance, outbreaks of crown-of-thorns starfish (COTS), a corallivore, can destroy coral reefs. Here, we examine the gene expression in gravid male and female COTS prior to spawning in the wild, to identify genome-encoded factors that may regulate aggregation and spawning. This study is informed by a previously identified exoproteome that attracts conspecifics. To capture the natural gene expression profiles, we isolated RNAs from gravid female and male COTS immediately after they were removed from the Great Barrier Reef. RESULTS: Sexually dimorphic gene expression is present in all seven somatic tissues and organs that we surveyed and in the gonads. Approximately 40% of the exoproteome transcripts are differentially expressed between sexes. Males uniquely upregulate an additional 68 secreted factors in their testes. A suite of neuropeptides in sensory organs, coelomocytes and gonads is differentially expressed between sexes, including the relaxin-like gonad-stimulating peptide and gonadotropin-releasing hormones. Female sensory tentacles-chemosensory organs at the distal tips of the starfish arms-uniquely upregulate diverse receptors and signalling molecules, including chemosensory G-protein-coupled receptors and several neuropeptides, including kisspeptin, SALMFamide and orexin. CONCLUSIONS Analysis of 103 tissue/organ transcriptomes from 13 wild COTS has revealed genes that are consistently differentially expressed between gravid females and males and that all tissues surveyed are sexually dimorphic at the molecular level. This finding is consistent with female and male COTS using sex-specific pheromones to regulate reproductive aggregations and synchronised spawning events. These pheromones appear to be received primarily by the sensory tentacles, which express a range of receptors and signalling molecules in a sex-specific manner. Furthermore, coelomocytes and gonads differentially express signalling and regulatory factors that control gametogenesis and spawning in other echinoderms.
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Affiliation(s)
- Mathias Jönsson
- grid.1003.20000 0000 9320 7537Centre for Marine Science, School of Biological Sciences, University of Queensland, Brisbane, QLD 4072 Australia
| | - Marie Morin
- grid.1003.20000 0000 9320 7537Centre for Marine Science, School of Biological Sciences, University of Queensland, Brisbane, QLD 4072 Australia
| | - Conan K. Wang
- grid.1003.20000 0000 9320 7537Institute for Molecular Bioscience, ARC Centre of Excellence for Innovations in Peptide and Protein Science, The University of Queensland, Brisbane, QLD 4072 Australia
| | - David J. Craik
- grid.1003.20000 0000 9320 7537Institute for Molecular Bioscience, ARC Centre of Excellence for Innovations in Peptide and Protein Science, The University of Queensland, Brisbane, QLD 4072 Australia
| | - Sandie M. Degnan
- grid.1003.20000 0000 9320 7537Centre for Marine Science, School of Biological Sciences, University of Queensland, Brisbane, QLD 4072 Australia
| | - Bernard M. Degnan
- grid.1003.20000 0000 9320 7537Centre for Marine Science, School of Biological Sciences, University of Queensland, Brisbane, QLD 4072 Australia
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Crown of thorns starfish life-history traits contribute to outbreaks, a continuing concern for coral reefs. Emerg Top Life Sci 2022; 6:67-79. [PMID: 35225331 PMCID: PMC9023020 DOI: 10.1042/etls20210239] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 01/22/2022] [Accepted: 02/03/2022] [Indexed: 11/24/2022]
Abstract
Crown of thorns starfish (COTS, Acanthaster sp.) are notorious for their destructive consumption of coral that decimates tropical reefs, an attribute unique among tropical marine invertebrates. Their populations can rapidly increase from 0–1 COTS ha−1 to more than 10–1000 COTS ha−1 in short order causing a drastic change to benthic communities and reducing the functional and species diversity of coral reef ecosystems. Population outbreaks were first identified to be a significant threat to coral reefs in the 1960s. Since then, they have become one of the leading causes of coral loss along with coral bleaching. Decades of research and significant investment in Australia and elsewhere, particularly Japan, have been directed towards identifying, understanding, and managing the potential causes of outbreaks and designing population control methods. Despite this, the drivers of outbreaks remain elusive. What is becoming increasingly clear is that the success of COTS is tied to their inherent biological traits, especially in early life. Survival of larval and juvenile COTS is likely to be enhanced by their dietary flexibility and resilience to variable food conditions as well as their phenotypically plastic growth dynamics, all magnified by the extreme reproductive potential of COTS. These traits enable COTS to capitalise on anthropogenic disturbances to reef systems as well as endure less favourable conditions.
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Hart MW, Guerra VI, Allen JD, Byrne M. Cloning and Selfing Affect Population Genetic Variation in Simulations of Outcrossing, Sexual Sea Stars. THE BIOLOGICAL BULLETIN 2021; 241:286-302. [PMID: 35015625 DOI: 10.1086/717293] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
AbstractMany sea stars are well known for facultative or obligate asexual reproduction in both the adult and larval life-cycle stages. Some species and lineages are also capable of facultative or obligate hermaphroditic reproduction with self-fertilization. However, models of population genetic variation and empirical analyses of genetic data typically assume only sexual reproduction and outcrossing. A recent reanalysis of previously published empirical data (microsatellite genotypes) from two studies of one of the most well-known sea star species (the crown-of-thorns sea star; Acanthaster sp.) concluded that cloning and self-fertilization in that species are rare and contribute little to patterns of population genetic variation. Here we reconsider that conclusion by simulating the contribution of cloning and selfing to genetic variation in a series of models of sea star demography. Simulated variation in two simple models (analogous to previous analyses of empirical data) was consistent with high rates of cloning or selfing or both. More realistic scenarios that characterize population flux in sea stars of ecological significance, including outbreaks of crown-of-thorns sea stars that devastate coral reefs, invasions by Asterias amurensis, and epizootics of sea star wasting disease that kill Pisaster ochraceus, also showed significant but smaller effects of cloning and selfing on variation within subpopulations and differentiation between subpopulations. Future models or analyses of genetic variation in similar study systems might benefit from simulation modeling to characterize possible contributions of cloning or selfing to genetic variation in population samples or to understand the limits on inferring the effects of cloning or selfing in nature.
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Guerra VI, Haynes G, Byrne M, Hart MW. Selection on genes associated with the evolution of divergent life histories: Gamete recognition or something else? Evol Dev 2021; 23:423-438. [PMID: 34549504 DOI: 10.1111/ede.12392] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2020] [Revised: 04/17/2021] [Accepted: 06/02/2021] [Indexed: 12/13/2022]
Abstract
Gamete compatibility, and fertilization success, is mediated by gamete-recognition genes (GRGs) that are expected to show genetic evidence of a response to sexual selection associated with mating system traits. Changes in the strength of sexual selection can arise from the resolution of sperm competition among males, sexual conflicts of interest between males and females, or other mechanisms of sexual selection. To assess these expectations, we compared patterns of episodic diversifying selection among genes expressed in the gonads of Cryptasterina pentagona and C. hystera, which recently speciated and have evolved different mating systems (gonochoric or hermaphroditic), modes of fertilization (outcrossing or selfing), and dispersal (planktonic larvae or internal brooding). Cryptasterina spp. inhabit the upper intertidal of the coast of Queensland and coral islands of the Great Barrier Reef. We found some evidence for positive selection on a GRG in the outcrossing C. pentagona, and we found evidence of loss of gene function in a GRG of the self-fertilizing C. hystera. The modification or loss of gene functionality may be evidence of relaxed selection on some aspects of gamete interaction in C. hystera. In addition to these genes involved in gamete interactions, we also found genes under selection linked to abiotic stress, chromosomal regulation, polyspermy, and egg-laying. We interpret those results as possible evidence that Cryptasterina spp. with different mating systems may have been adapting in divergent ways to oxidative stress or other factors associated with reproduction in the physiologically challenging environment of the high intertidal. RESEARCH HIGHLIGHTS: Recent speciation between two sea stars was unlikely the result of selection on gamete-recognition genes annotated in this study. Instead, our results point to selection on genes linked to the intertidal environment and reproduction.
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Affiliation(s)
- Vanessa I Guerra
- Department of Biological Sciences and Crawford Laboratory of Evolutionary Studies, Simon Fraser University, Burnaby, British Columbia, Canada.,Department of Invertebrate Zoology, National Museum of Natural History, Smithsonian Institution, Washington, District of Columbia, USA
| | - Gwilym Haynes
- Department of Biological Sciences and Crawford Laboratory of Evolutionary Studies, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Maria Byrne
- School of Biological Sciences, University of Sydney, Sydney, New South Wales, Australia
| | - Michael W Hart
- Department of Biological Sciences and Crawford Laboratory of Evolutionary Studies, Simon Fraser University, Burnaby, British Columbia, Canada
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Deaker DJ, Agüera A, Lin HA, Lawson C, Budden C, Dworjanyn SA, Mos B, Byrne M. The hidden army: corallivorous crown-of-thorns seastars can spend years as herbivorous juveniles. Biol Lett 2020; 16:20190849. [PMID: 32264781 DOI: 10.1098/rsbl.2019.0849] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Crown-of-thorns seastar (COTS) outbreaks are a major threat to coral reefs. Although the herbivorous juveniles and their switch to corallivory are key to seeding outbreaks, they remain a black box in our understanding of COTS. We investigated the impact of a delay in diet transition due to coral scarcity in cohorts reared on crustose coralline algae for 10 months and 6.5 years before being offered coral. Both cohorts achieved an asymptotic size (16-18 mm diameter) on algae and had similar exponential growth on coral. After 6.5 years of herbivory, COTS were competent coral predators. This trophic and growth plasticity results in a marked age-size disconnect adding unappreciated complexity to COTS boom-bust dynamics. The potential that herbivorous juveniles accumulate in the reef infrastructure to seed outbreaks when favourable conditions arise has implications for management of COTS populations.
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Affiliation(s)
- Dione J Deaker
- School of Medical Sciences, The University of Sydney, Sydney, New South Wales, Australia
| | | | - Huang-An Lin
- National Marine Science Centre, Southern Cross University, Coffs Harbour, New South Wales, Australia
| | - Corinne Lawson
- National Marine Science Centre, Southern Cross University, Coffs Harbour, New South Wales, Australia
| | - Claire Budden
- School of Life and Environmental Sciences, The University of Sydney, Sydney, New South Wales, Australia
| | - Symon A Dworjanyn
- National Marine Science Centre, Southern Cross University, Coffs Harbour, New South Wales, Australia
| | - Benjamin Mos
- National Marine Science Centre, Southern Cross University, Coffs Harbour, New South Wales, Australia
| | - Maria Byrne
- School of Medical Sciences, The University of Sydney, Sydney, New South Wales, Australia.,School of Life and Environmental Sciences, The University of Sydney, Sydney, New South Wales, Australia
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