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Jairo Rivera-posada - One of the best experts on this subject based on the ideXlab platform.
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De novo assembly of the transcriptome of Acanthaster Planci testes
Molecular ecology resources, 2014Co-Authors: Michael J. Stewart, Praphaporn Stewart, Jairo Rivera-posadaAbstract:A key strategy to reduce coral loss is the development of effective control method for the corallivorous crown-of-thorns sea star (Acanthaster Planci), an omnipresent scourge and threat to the biodiversity of reefs in the Indo-Pacific region. Limited genetic resources are available for this highly fecund species. In this study, we explored one aspect at the heart of A. Planci outbreaks, the male reproductive system. Using high-throughput sequencing technology, we report for first time the production of a comprehensive transcriptomic data set for the testes of A. placni that can aid in understanding the molecular mechanisms involved in A. Planci spermatogenesis and fertilization. Through de novo transcriptome sequencing, we produced 52 965 998 raw reads corresponding to 4.76 Gb clean read data. From this, 243 870 contigs were assembled with Trinity and used to construct 92 792 unigenes. Distinct genes were then annotated with blastx yielding 30 810 unigenes above the cut-off E-value set at 10−5, with ESTScan database query analyses yielding up to 5366 unigenes to known hits. The identification of genes directly involved in sperm development (DEAD-box family proteins), motility, fertilization and signalling (Bindin/Speract receptor) are also discussed.
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Osmotic shock as alternative method to control Acanthaster Planci
Journal of Coastal Life Medicine, 2014Co-Authors: Jairo Rivera-posada, Leigh OwensAbstract:Objective: To test six osmotic stressors as alternative methods to control Acanthaster Planci (A. Planci) outbreaks by exploiting their incapacity to tolerate drastic changes in osmolarity. Finding more effective ways to control A. Planci outbreaks is one of the most immediate and effective ways by which to reverse rapid declines in the abundance of live coral cover in the Indo-Pacific. Methods: A total of 10 mL of each of the following chemicals: sodium chloride, ethylenediaminetetraacetic acid, sodium carbonate, sodium cholate, sodium deoxycholate, urea and mannitol were injected into individual healthy sea stars to examine which chemicals induced disease and death. Results: Four out of six chemicals used in this study induced disease. Sodium chloride, sodium cholate, sodium deoxycholate and ethylenediaminetetraacetic acid are capable of inducing death in injected sea stars offering an alternative option to control A. Planci outbreaks. Conclusions: Hyperosmotic stress is a viable alternative to control A. Planci outbreaks as massive cell death results when acute hypertonicity exceeds a certain level.
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Injection of Acanthaster Planci with thiosulfate-citrate-bile-sucrose agar (TCBS). I. Disease induction.
Diseases of aquatic organisms, 2011Co-Authors: Jairo Rivera-posada, Morgan S. Pratchett, Ana Cano-gómez, J. D. Arango-gómez, Leigh OwensAbstract:This is the first report of the successful induction of a transmissible disease in the coral-eating crown-of-thorns starfish Acanthaster Planci (COTS). Injection of thiosulfate-citrate-bile-sucrose agar (TCBS) culture medium into COTS induced a disease characterized by discoloured and necrotic skin, ulcerations, loss of body turgor, accumulation of colourless mucus on many spines especially at their tip, and loss of spines. Blisters on the dorsal integument broke through the skin surface and resulted in large, open sores that exposed the internal organs. Oedema and reddened digestive tissues and destruction of connective fibers were common. Moreover, healthy COTS in contact with these infected animals also displayed signs of disease and died within 24 h. TCBS induced 100% mortality in injected starfish. There was no introduction of new pathogens into the marine environment. TCBS promoted the growth of COTS' naturally occurring Vibrionales to high densities with subsequent symbiont imbalance followed by disease and death.
Scott F. Cummins - One of the best experts on this subject based on the ideXlab platform.
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Putative chemosensory receptors are differentially expressed in the sensory organs of male and female crown-of-thorns starfish, Acanthaster Planci.
BMC genomics, 2018Co-Authors: Rebecca Roberts, Daniel Powell, Tianfang Wang, M H Hall, Cherie A. Motti, Scott F. CumminsAbstract:Background Chemosensation is a critical signalling process for all organisms and is achieved through the interaction between chemosensory receptors and their ligands. The Crown-of-thorns starfish, Acanthaster Planci species complex (COTS), is a predator of coral polyps and Acanthaster cf. solaris is currently considered to be one of the main drivers of coral loss on the Great Barrier Reef in Queensland, Australia.
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The neuropeptidome of the Crown-of-Thorns Starfish, Acanthaster Planci.
Journal of proteomics, 2017Co-Authors: Meaghan K. Smith, Michael R. Hall, Tianfang Wang, Cherie A. Motti, Saowaros Suwansa-ard, Abigail Elizur, Min Zhao, Matthew L. Rowe, Maurice R. Elphick, Scott F. CumminsAbstract:Abstract Outbreaks of Crown-of-Thorns Starfish (COTS; Acanthaster Planci ) are a major cause of destruction of coral communities on the Australian Great Barrier Reef. While factors relating to population explosions and the social interactions of COTS have been well studied, little is known about the neural mechanisms underlying COTS physiology and behaviour. One of the major classes of chemical messengers that regulate physiological and behavioural processes in animals is the neuropeptides. Here, we have analysed COTS genome and transcriptome sequence data to identify neuropeptide precursor proteins in this species. A total of 48 neuropeptide precursors were identified, including homologs of neuropeptides that are evolutionarily conserved throughout the Bilateria, and others that are novel. Proteomic mass spectrometry was employed to confirm the presence of neuropeptides in extracts of radial nerve cords. These transcriptomic and proteomic resources provide a foundation for functional studies that will enable a better understanding of COTS physiology and behaviour, and may facilitate development of novel population biocontrol methods. Significance The Crown-of-Thorns Starfish (COTS) is one of the primary factors leading to coral loss on the Great Barrier Reef, Australia. Our combined gene and proteomic findings of this study reveal the COTS neuropeptidome, including both echinoderm-like neuropeptides and novel putative neuropeptides. This represents the most comprehensive neuropeptidome for an echinoderm, contributing to the evolving knowledge of the COTS molecular neurobiology that may assist towards the development of biocontrol methods.
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Identification of putative olfactory G-protein coupled receptors in Crown-of-Thorns starfish, Acanthaster Planci
BMC genomics, 2017Co-Authors: Rebecca Roberts, Kenneth W. Baughman, Michael R. Hall, Cherie A. Motti, Noriyuki Satoh, Scott F. CumminsAbstract:Abstract Background In marine organisms, and in particular for benthic invertebrates including echinoderms, olfaction is a dominant sense with chemosensation being a critical signalling process. Until recently natural product chemistry was the primary investigative approach to elucidate the nature of chemical signals but advances in genomics and transcriptomics over the last decade have facilitated breakthroughs in understanding not only the chemistry but also the molecular mechanisms underpinning chemosensation in aquatic environments. Integration of these approaches has the potential to reveal the fundamental elements influencing community structure of benthic ecosystems as chemical signalling modulates intra- and inter-species interactions. Such knowledge also offers avenues for potential development of novel biological control methods for pest species such as the predatory Crown-of-Thorns starfish (COTS), Acanthaster Planci which are the primary biological cause of coral cover loss in the Indo-Pacific. Results In this study, we have analysed the COTS sensory organs through histological and electron microscopy. We then investigated key elements of the COTS molecular olfactory toolkit, the putative olfactory rhodopsin-like G protein-protein receptors (GPCRs) within its genome and olfactory organ transcriptomes. Many of the identified Acanthaster Planci olfactory receptors ( ApORs ) genes were found to cluster within the COTS genome, indicating rapid evolution and replication from an ancestral olfactory GPCR sequence. Tube feet and terminal sensory tentacles contain the highest proportion of ApORs . In situ hybridisation confirmed the presence of four ApORs , ApOR15, 18, 25 and 43 within COTS sensory organs, however expression of these genes was not specific to the adhesive epidermis, but also within the nerve plexus of tube feet stems and within the myomesothelium. G alpha subunit proteins were also identified in the sensory organs, and we report the spatial localisation of Gαi within the tube foot and sensory tentacle. Conclusions We have identified putative COTS olfactory receptors that localise to sensory organs. These results provide a basis for future studies that may enable the development of a biological control not only for COTS, but also other native pest or invasive starfish.
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Genomic organization of Hox and ParaHox clusters in the echinoderm, Acanthaster Planci
Genesis (New York N.Y. : 2000), 2014Co-Authors: Kenneth W. Baughman, Carmel Mcdougall, Scott F. Cummins, Michael R. Hall, Bernard M. Degnan, Nori Satoh, Eiichi ShoguchiAbstract:Summary: The organization of echinoderm Hox clusters is of interest due to the role that Hox genes play in deuterostome development and body plan organization, and the unique gene order of the Hox complex in the sea urchin Strongylocentrotus purpuratus, which has been linked to the unique development of the axial region. Here, it has been reported that the Hox and ParaHox clusters of Acanthaster Planci, a corallivorous starfish found in the Pacific and Indian oceans, generally resembles the chordate and hemichordate clusters. The A. Planci Hox cluster shared with sea urchins the loss of one of the medial Hox genes, even-skipped (Evx) at the anterior of the cluster, as well as organization of the posterior Hox genes.
Kazuo Nadaoka - One of the best experts on this subject based on the ideXlab platform.
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seven new microsatellite markers for crown of thorns starfish Acanthaster Planci
Plankton and Benthos Research, 2007Co-Authors: Nina Yasuda, Satoshi Nagai, Masami Hamaguchi, Kazuo NadaokaAbstract:We isolated seven additional polymorphic microsatellites from the crown-of-thorns starfish, Acanthaster Planci. These loci provide one class of highly variable genetic markers, as the number of alleles ranged from 5 to 13 and the observed and expected heterozygosities ranged from 0.083 to 0.957 and from 0.082 to 0.872, respectively. After Mann-Whitney test, there was no significant difference in the number of alleles, the PCR efficiency, and the observed and expected heterozygosities between the newly developed 7 markers and the previously reported markers. We consider that these loci are potentially useful for detailing the genetic structure and gene flow among A. Planci populations.
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development of microsatellite markers for the crown of thorns starfish Acanthaster Planci
Molecular Ecology Notes, 2006Co-Authors: Nina Yasuda, Satoshi Nagai, Masami Hamaguchi, C. L. Lian, Kazuo NadaokaAbstract:We isolated nine polymorphic microsatellites from the crown-of-thorns starfish, Acanthaster Planci. These loci provide one class of highly variable genetic marker as the number of alleles ranged from three to 12 and the observed and expected heterozygosities ranged from 0.130 to 0.783 and from 0.163 to 0.862, respectively. We consider that these loci are potentially useful for detailing the genetic structure and gene flow among A. Planci populations.
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Complete mitochondrial genome sequences for Crown-of-thorns starfish Acanthaster Planci and Acanthaster brevispinus.
BMC genomics, 2006Co-Authors: Nina Yasuda, Satoshi Nagai, Masami Hamaguchi, Miho Sasaki, Masaki Saba, Kazuo NadaokaAbstract:Background The crown-of-thorns starfish, Acanthaster Planci (L.), has been blamed for coral mortality in a large number of coral reef systems situated in the Indo-Pacific region. Because of its high fecundity and the long duration of the pelagic larval stage, the mechanism of outbreaks may be related to its meta-population dynamics, which should be examined by larval sampling and population genetic analysis. However, A. Planci larvae have undistinguished morphological features compared with other asteroid larvae, hence it has been difficult to discriminate A. Planci larvae in plankton samples without species-specific markers. Also, no tools are available to reveal the dispersal pathway of A. Planci larvae. Therefore the development of highly polymorphic genetic markers has the potential to overcome these difficulties. To obtain genomic information for these purposes, the complete nucleotide sequences of the mitochondrial genome of A. Planci and its putative sibling species, A. brevispinus were determined and their characteristics discussed.
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Development of microsatellite markers for the crown‐of‐thorns starfish Acanthaster Planci
Molecular Ecology Notes, 2006Co-Authors: Nina Yasuda, Satoshi Nagai, Masami Hamaguchi, C. L. Lian, Kazuo NadaokaAbstract:We isolated nine polymorphic microsatellites from the crown-of-thorns starfish, Acanthaster Planci. These loci provide one class of highly variable genetic marker as the number of alleles ranged from three to 12 and the observed and expected heterozygosities ranged from 0.130 to 0.783 and from 0.163 to 0.862, respectively. We consider that these loci are potentially useful for detailing the genetic structure and gene flow among A. Planci populations.
Morgan S. Pratchett - One of the best experts on this subject based on the ideXlab platform.
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Capacity for regeneration in crown of thorns starfish, Acanthaster Planci
Coral Reefs, 2013Co-Authors: Vanessa Messmer, Morgan S. Pratchett, Timothy ClarkAbstract:[Extract] Population outbreaks of the coral-feeding crown of thorns starfish, Acanthaster Planci (Fig. 1a), are, with storms, the most significant disturbance on coral reefs in the western Pacific (e.g., De'ath et al. 2012). Controlling outbreaks of A. Planci is therefore increasingly viewed as a key strategy in reducing coral loss and reef degradation. Initial control efforts in the 1960s involved sectioning starfish and leaving them in situ, but there were subsequent anecdotal reports that A. Planci could regenerate from small pieces of remnant tissue. Regeneration is a common characteristic amongst echinoderms as a form of asexual reproduction, or following loss of appendages through predation, stress or disease. Regeneration has been recorded in at least 21 species within the Asteroidea (Emson and Wilkie 1980).
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Injection of Acanthaster Planci with thiosulfate-citrate-bile-sucrose agar (TCBS). I. Disease induction.
Diseases of aquatic organisms, 2011Co-Authors: Jairo Rivera-posada, Morgan S. Pratchett, Ana Cano-gómez, J. D. Arango-gómez, Leigh OwensAbstract:This is the first report of the successful induction of a transmissible disease in the coral-eating crown-of-thorns starfish Acanthaster Planci (COTS). Injection of thiosulfate-citrate-bile-sucrose agar (TCBS) culture medium into COTS induced a disease characterized by discoloured and necrotic skin, ulcerations, loss of body turgor, accumulation of colourless mucus on many spines especially at their tip, and loss of spines. Blisters on the dorsal integument broke through the skin surface and resulted in large, open sores that exposed the internal organs. Oedema and reddened digestive tissues and destruction of connective fibers were common. Moreover, healthy COTS in contact with these infected animals also displayed signs of disease and died within 24 h. TCBS induced 100% mortality in injected starfish. There was no introduction of new pathogens into the marine environment. TCBS promoted the growth of COTS' naturally occurring Vibrionales to high densities with subsequent symbiont imbalance followed by disease and death.
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injection of Acanthaster Planci with thiosulfate citrate bile sucrose agar tcbs ii histopathological changes
Diseases of Aquatic Organisms, 2011Co-Authors: Jairo Riveraposada, Morgan S. Pratchett, Leigh OwensAbstract:We assessed histological changes in the tissues of the crown-of-thorns starfish Acanthaster Planci (COTS) after injection of thiosulfate-citrate-bile-sucrose agar (TCBS) which was used as a disease inducer (potential outbreak control method), by conventional and scanning electron microscopy. Digestive glands were processed and stained with hematoxylin and eosin to describe the histological architecture of the intestinal epithelium. Subsequently comparison of healthy versus infected tissues and Gram stains were carried out to confirm bacterial occurrence on infected tissues, characterize the structural changes induced by bacterial communities in COTS tissues, and to determine if the histopathological changes of intestinal tissues were consistent with vibrio infection. TCBS injections induced marked epithelial desquamation, hypertrophy and hypersecretion of glandular cells, epithelial cell destruction, pyknosis, reduction of thickness and disorganization of connective tissue and associated nerve plexus, presence of bacterial colonies, irregular eosinophilic foci in glandular cells, brush border disruption, atrophy and detachment of intestinal microvilli and cell debris in the lumen. All these changes were attributed to a fulminating systemic dysbiosis and were consistent with vibrio infections.
J.s. Lucas - One of the best experts on this subject based on the ideXlab platform.
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Selective feeding by larvae of the crown-of-thorns starfish, Acanthaster Planci (L.)
Coral Reefs, 1997Co-Authors: K. Okaji, Tenshi Ayukai, J.s. LucasAbstract:The effect of phytoplankton size on feeding rates of planktonic larvae of the crown-of-thorns starfish Acanthaster Planci (L.) was evaluated by examining their gut contents under an epifluorescence microscope. Concentrations of coccoid cyanobacteria in natural seawater ranged between 1.73 and 5.33 x 10(5) cells ml(-1) and were three to four orders of magnitude greater than that of eukaryotes. Under these conditions, A. Planci larvae ingested similar or smaller numbers of cyanobacteria than eukaryotes. Consequently, clearance rates of A. Planci larvae on cyanobacteria were approximately three orders of magnitude lower than those on eukaryotes. Cyanobacteria and eukaryotes in the gut of A. Planci larvae had mean equivalent spherical diameters (ESD) of 1-2 mu m and 3.6-4.6 mu m, respectively. Thus, the volume of cyanobacteria ingested was less than 10% of the volume of eukaryotes ingested. Acanthaster Planci larvae were fed cultured phytoplankton Dunaliella tertiolecta and suspensions of three different sizes of plastic beads with fluorescence labelling. There was no significant difference in clearance rates on 6 and 20 mu m plastic beads. Clearance rates on 1 mu m plastic beads were, however, much lower than those on 6 and 20 mu m plastic beads. Clearance rates of A. Planci larvae on D. tertiolecta (ca. 5 mu m ESD) were significantly higher than those on 6 and 20 mu m plastic beads. Apart from particle size, this result shows that feeding of A. Planci larvae is influenced by other properties of potential food particles.