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Pinto A, Botelho MJ, Churro C, Asselman J, Pereira P, Pereira JL. A review on aquatic toxins - Do we really know it all regarding the environmental risk posed by phytoplankton neurotoxins? J Environ Manage 2023; 345:118769. [PMID: 37597370 DOI: 10.1016/j.jenvman.2023.118769] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 07/24/2023] [Accepted: 08/09/2023] [Indexed: 08/21/2023]
Abstract
Aquatic toxins are potent natural toxins produced by certain cyanobacteria and marine algae species during harmful cyanobacterial and algal blooms (CyanoHABs and HABs, respectively). These harmful bloom events and the toxins produced during these events are a human and environmental health concern worldwide, with occurrence, frequency and severity of CyanoHABs and HABs being predicted to keep increasing due to ongoing climate change scenarios. These contexts, as well as human health consequences of some toxins produced during bloom events have been thoroughly reviewed before. Conversely, the wider picture that includes the non-human biota in the assessment of noxious effects of toxins is much less covered in the literature and barely covered by review works. Despite direct human exposure to aquatic toxins and related deleterious effects being responsible for the majority of the public attention to the blooms' problematic, it constitutes a very limited fraction of the real environmental risk posed by these toxins. The disruption of ecological and trophic interactions caused by these toxins in the aquatic biota building on deleterious effects they may induce in different species is paramount as a modulator of the overall magnitude of the environmental risk potentially involved, thus necessarily constraining the quality and efficiency of the management strategies that should be placed. In this way, this review aims at updating and consolidating current knowledge regarding the adverse effects of aquatic toxins, attempting to going beyond their main toxicity pathways in human and related models' health, i.e., also focusing on ecologically relevant model organisms. For conciseness and considering the severity in terms of documented human health risks as a reference, we restricted the detailed revision work to neurotoxic cyanotoxins and marine toxins. This comprehensive revision of the systemic effects of aquatic neurotoxins provides a broad overview of the exposure and the hazard that these compounds pose to human and environmental health. Regulatory approaches they are given worldwide, as well as (eco)toxicity data available were hence thoroughly reviewed. Critical research gaps were identified particularly regarding (i) the toxic effects other than those typical of the recognized disease/disorder each toxin causes following acute exposure in humans and also in other biota; and (ii) alternative detection tools capable of being early-warning signals for aquatic toxins occurrence and therefore provide better human and environmental safety insurance. Future directions on aquatic toxins research are discussed in face of the existent knowledge, with particular emphasis on the much-needed development and implementation of effective alternative (eco)toxicological biomarkers for these toxins. The wide-spanning approach followed herein will hopefully stimulate future research more broadly addressing the environmental hazardous potential of aquatic toxins.
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Affiliation(s)
- Albano Pinto
- CESAM - Centre for Environmental and Marine Studies, Department of Biology, University of Aveiro, Portugal.
| | - Maria João Botelho
- IPMA, Portuguese Institute for the Sea and Atmosphere, Av. Alfredo Magalhães Ramalho 6, 1495-165, Algés, Portugal; CIIMAR, Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Terminal de Cruzeiros do Porto, Av. General Norton de Matos s/n, 4450-208, Matosinhos, Portugal
| | - Catarina Churro
- IPMA, Portuguese Institute for the Sea and Atmosphere, Av. Alfredo Magalhães Ramalho 6, 1495-165, Algés, Portugal; CIIMAR, Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Terminal de Cruzeiros do Porto, Av. General Norton de Matos s/n, 4450-208, Matosinhos, Portugal
| | - Jana Asselman
- Blue Growth Research Lab, Ghent University, Bluebridge Building, Ostend Science Park 1, 8400, Ostend, Belgium
| | - Patrícia Pereira
- CESAM - Centre for Environmental and Marine Studies, Department of Biology, University of Aveiro, Portugal
| | - Joana Luísa Pereira
- CESAM - Centre for Environmental and Marine Studies, Department of Biology, University of Aveiro, Portugal
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Abassi S, Kim HS, Bui QTN, Ki JS. Effects of nitrate on the saxitoxins biosynthesis revealed by sxt genes in the toxic dinoflagellate Alexandrium pacificum (group IV). Harmful Algae 2023; 127:102473. [PMID: 37544673 DOI: 10.1016/j.hal.2023.102473] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 06/09/2023] [Accepted: 06/10/2023] [Indexed: 08/08/2023]
Abstract
The dinoflagellate Alexandrium pacificum (group IV) is of particular interest because of its involvement in harmful algal blooms and production of saxitoxin (STX), which causes paralytic shellfish poisoning. The toxicity from STX and its analogues (STXs) is suspected to be affected by nitrogen (N) availability. However, the toxicity-associated behavior and STX-biosynthesis gene responses of the toxic A. pacificum under N fluctuations have not been sufficiently investigated. In the present study, we identified the sxtI gene involved in sxt biosynthesis pathway and evaluated the effects of nitrate (NO3-) on STXs production and the expression of four sxt core genes (sxtA4, sxtG, sxtB, and sxtI). Quantification of total STXs levels in the cultures under different NO3- regimes showed that NO3- concentration influenced STXs production. In addition, the proportion and concentration of STXs varied depending on the NO3- concentration. Core sxt transcript abundance was also influenced by available NO3- in a time-dependent manner. Expressional levels and patterns of sxtI were correlated with those of sxtA and sxtB. The relationship between the toxins and sxt responses in A. pacificum under various NO3- regimes suggests the direct involvement of N in the STXs biosynthesis pathway. Understanding this link would provide a tool to understand the toxin dynamics of dinoflagellates following N shifts in marine environments.
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Affiliation(s)
- Sofia Abassi
- Department of Biotechnology, Sangmyung University, Seoul, 03016, Republic of Korea
| | - Han-Sol Kim
- Department of Biotechnology, Sangmyung University, Seoul, 03016, Republic of Korea
| | - Quynh Thi Nhu Bui
- Department of Biotechnology, Sangmyung University, Seoul, 03016, Republic of Korea
| | - Jang-Seu Ki
- Department of Biotechnology, Sangmyung University, Seoul, 03016, Republic of Korea.
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Ruvindy R, Barua A, Bolch CJS, Sarowar C, Savela H, Murray SA. Genomic copy number variability at the genus, species and population levels impacts in situ ecological analyses of dinoflagellates and harmful algal blooms. ISME Commun 2023; 3:70. [PMID: 37422553 PMCID: PMC10329664 DOI: 10.1038/s43705-023-00274-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 06/18/2023] [Accepted: 06/20/2023] [Indexed: 07/10/2023]
Abstract
The application of meta-barcoding, qPCR, and metagenomics to aquatic eukaryotic microbial communities requires knowledge of genomic copy number variability (CNV). CNV may be particularly relevant to functional genes, impacting dosage and expression, yet little is known of the scale and role of CNV in microbial eukaryotes. Here, we quantify CNV of rRNA and a gene involved in Paralytic Shellfish Toxin (PST) synthesis (sxtA4), in 51 strains of 4 Alexandrium (Dinophyceae) species. Genomes varied up to threefold within species and ~7-fold amongst species, with the largest (A. pacificum, 130 ± 1.3 pg cell-1 /~127 Gbp) in the largest size category of any eukaryote. Genomic copy numbers (GCN) of rRNA varied by 6 orders of magnitude amongst Alexandrium (102- 108 copies cell-1) and were significantly related to genome size. Within the population CNV of rRNA was 2 orders of magnitude (105 - 107 cell-1) in 15 isolates from one population, demonstrating that quantitative data based on rRNA genes needs considerable caution in interpretation, even if validated against locally isolated strains. Despite up to 30 years in laboratory culture, rRNA CNV and genome size variability were not correlated with time in culture. Cell volume was only weakly associated with rRNA GCN (20-22% variance explained across dinoflagellates, 4% in Gonyaulacales). GCN of sxtA4 varied from 0-102 copies cell-1, was significantly related to PSTs (ng cell-1), displaying a gene dosage effect modulating PST production. Our data indicate that in dinoflagellates, a major marine eukaryotic group, low-copy functional genes are more reliable and informative targets for quantification of ecological processes than unstable rRNA genes.
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Affiliation(s)
- Rendy Ruvindy
- University of Technology Sydney, School of Life Sciences, Sydney, PO Box 123, Broadway, NSW, 2007, Australia
| | - Abanti Barua
- University of Technology Sydney, School of Life Sciences, Sydney, PO Box 123, Broadway, NSW, 2007, Australia
| | - Christopher J S Bolch
- Institute for Marine & Antarctic Studies, University of Tasmania, Launceston, 7248, TAS, Australia
| | - Chowdhury Sarowar
- Sydney Institute of Marine Science, Chowder Bay Rd, Mosman, NSW, Australia
| | - Henna Savela
- University of Technology Sydney, School of Life Sciences, Sydney, PO Box 123, Broadway, NSW, 2007, Australia
- Finnish Environment Institute, Marine Research Centre, Helsinki, Finland
| | - Shauna A Murray
- University of Technology Sydney, School of Life Sciences, Sydney, PO Box 123, Broadway, NSW, 2007, Australia.
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Jiang Y, Li Z. Identification and genomic analysis of Pseudosulfitobacter koreense sp. nov. isolated from toxin-producing dinoflagellate Alexandrium pacificum. Arch Microbiol 2023; 205:245. [PMID: 37209217 DOI: 10.1007/s00203-023-03583-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 05/11/2023] [Accepted: 05/12/2023] [Indexed: 05/22/2023]
Abstract
The bacterial strain AP-MA-4T isolated from the marine dinoflagellate Alexandrium pacificum (KCTC AG60911), was subjected to a taxonomic analysis. Cells of strain AP-MA-4T were Gram-stain-negative, aerobic, rod-shaped, optimum growth at 20 °C, pH 7.0, in the presence of 5% (w/v) NaCl. Strain AP-MA-4T shared the highest 16S rRNA gene sequence similarity to Pseudosulfitobacter pseudonitzschiae DSM 26824T (98.5%), followed by Ascidiaceihabitans donghaensis RSS1-M3T (96.3%), Pseudoseohaeicola caenipelagi BS-W13T (95.7%), and Sulfitobacter pontiacus CHLG 10T (95.3%). Based on 16S rRNA phylogeny, strain AP-MA-4T is phylogenetically closely related to Pseudosulfitobacter pseudonitzschiae (type species of Pseudosulfitobacter) and could be distinguished from the type species based on their phenotypic properties. The genome length of strain AP-MA-4T was 3.48 Mbp with a 62.9% G + C content. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between strain AP-MA-4 T and its closely related type strains were 72.2-83.3 and 18.2-27.6%, respectively. Summed feature 8 (C18:1ω7c and/or C18:1ω6c) was identified the major fatty acids (> 10%). Phosphatidylglycerol (PG), phosphatidylethanolamine (PE), and phospholipid (PL) were demonstrated as the major polar lipids. The major respiratory quinone is ubiquinone-10 (Q-10). Based on genotypic and phenotypic features, strain AP-MA-4T (= KCTC 92289T = GDMCC 1.3585T) represents a new Pseudosulfitobacter species, in which the name Pseudosulfitobacter koreense sp. nov. is proposed.
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Affiliation(s)
- Yue Jiang
- Biological Resource Center/Korean Collection for Type Cultures (KCTC), Korea Research Institute of Bioscience and Biotechnology, Jeongeup, 56212, Republic of Korea
- Department of Integrative Food, Bioscience and Biotechnology, Chonnam National University, Gwangju, 61186, Republic of Korea
| | - Zhun Li
- Biological Resource Center/Korean Collection for Type Cultures (KCTC), Korea Research Institute of Bioscience and Biotechnology, Jeongeup, 56212, Republic of Korea.
- Department of Environmental Biotechnology, KRIBB School of Biotechnology, University of Science and Technology (UST), Daejeon, 34113, Republic of Korea.
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Casanova LM, Macrae A, de Souza JE, Neves Junior A, Vermelho AB. The Potential of Allelochemicals from Microalgae for Biopesticides. Plants (Basel) 2023; 12:plants12091896. [PMID: 37176954 PMCID: PMC10181251 DOI: 10.3390/plants12091896] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 05/03/2023] [Accepted: 05/04/2023] [Indexed: 05/15/2023]
Abstract
Improvements in agricultural productivity are required to meet the demand of a growing world population. Phytopathogens, weeds, and insects are challenges to agricultural production. The toxicity and widespread application of persistent synthetic pesticides poses a major threat to human and ecosystem health. Therefore, sustainable strategies to control pests are essential for agricultural systems to enhance productivity within a green paradigm. Allelochemicals are a less persistent, safer, and friendly alternative to efficient pest management, as they tend to be less toxic to non-target organisms and more easily degradable. Microalgae produce a great variety of allelopathic substances whose biocontrol potential against weeds, insects, and phytopathogenic fungi and bacteria has received much attention. This review provides up-to-date information and a critical perspective on allelochemicals from microalgae and their potential as biopesticides.
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Affiliation(s)
- Livia Marques Casanova
- Biotechnology Center-Bioinovar, Institute of Microbiology Paulo de Goes, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro 21941-902, RJ, Brazil
| | - Andrew Macrae
- Sustainable Biotechnology and Microbial Bioinformatics Laboratory, Institute of Microbiology Paulo de Goes, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro 21941-902, RJ, Brazil
| | - Jacqueline Elis de Souza
- Biotechnology Center-Bioinovar, Institute of Microbiology Paulo de Goes, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro 21941-902, RJ, Brazil
| | - Athayde Neves Junior
- Biotechnology Center-Bioinovar, Institute of Microbiology Paulo de Goes, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro 21941-902, RJ, Brazil
| | - Alane Beatriz Vermelho
- Biotechnology Center-Bioinovar, Institute of Microbiology Paulo de Goes, Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro 21941-902, RJ, Brazil
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Oyaneder-terrazas J, Figueroa D, Araneda OF, García C. Saxitoxin Group Toxins Accumulation Induces Antioxidant Responses in Tissues of Mytilus chilensis, Ameghinomya antiqua, and Concholepas concholepas during a Bloom of Alexandrium pacificum. Antioxidants (Basel) 2022; 11:392. [PMID: 35204273 PMCID: PMC8869173 DOI: 10.3390/antiox11020392] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 02/08/2022] [Accepted: 02/11/2022] [Indexed: 12/10/2022] Open
Abstract
Saxitoxin (STX) group toxins consist of a set of analogues which are produced by harmful algal blooms (HABs). During a HAB, filter-feeding marine organisms accumulate the dinoflagellates and concentrate the toxins in the tissues. In this study, we analyze the changes in antioxidant enzymes and oxidative damage in the bivalves Mytilus chilensis and Ameghinomya antiqua, and the gastropod Concholepas concholepas during a bloom of Alexandrium pacificum. The results show that during the exponential phase of the bloom bivalves show an increase in toxicity and activity of antioxidant enzymes (superoxide dismutase, catalase, glutathione peroxidase, and glutathinoe reductase, p < 0.05), while in the gastropods, increased activity of antioxidant enzymes was associated with the bioaccumulation of toxins through the diet. At the end of the bloom, decreased activity of antioxidant enzymes in the visceral and non-visceral tissues was detected in the bivalves, with an increase in oxidative damage (p < 0.05), in which the latter is correlated with the detection of the most toxic analogues of the STX-group (r = 0.988). In conclusion, in areas with high incidence of blooms, shellfish show a high activity of antioxidants, however, during the stages involving the distribution and bioconversion of toxins, there is decreased activity of antioxidant enzymes resulting in oxidative damage.
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Steele TS, Brunson JK, Maeno Y, Terada R, Allen AE, Yotsu-Yamashita M, Chekan JR, Moore BS. Domoic acid biosynthesis in the red alga Chondria armata suggests a complex evolutionary history for toxin production. Proc Natl Acad Sci U S A 2022; 119:e2117407119. [PMID: 35110408 DOI: 10.1073/pnas.2117407119] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/10/2021] [Indexed: 12/04/2022] Open
Abstract
Originally isolated from the red alga Chondria armata, domoic acid (DA) is best known as a potent marine neurotoxin produced by oceanic harmful algal blooms of planktonic diatoms. Sequencing efforts to date of kainoid-producing red algae have focused exclusively on a closely related molecule, kainic acid, leaving a gap in the understanding of DA biosynthesis in red algae and its evolutionary linkage to diatoms. Here, we present the phylogenetic and biochemical investigation of DA biosynthesis in C. armata. This work demonstrates the high synteny of DA biosynthetic genes between relatively distant taxonomic groups of algae and suggests a complex evolutionary history for DA biosynthesis involving gene transfer and neofunctionalization. Domoic acid (DA), the causative agent of amnesic shellfish poisoning, is produced by select organisms within two distantly related algal clades: planktonic diatoms and red macroalgae. The biosynthetic pathway to isodomoic acid A was recently solved in the harmful algal bloom–forming diatom Pseudonitzschia multiseries, establishing the genetic basis for the global production of this potent neurotoxin. Herein, we sequenced the 507-Mb genome of Chondria armata, the red macroalgal seaweed from which DA was first isolated in the 1950s, identifying several copies of the red algal DA (rad) biosynthetic gene cluster. The rad genes are organized similarly to the diatom DA biosynthesis cluster in terms of gene synteny, including a cytochrome P450 (CYP450) enzyme critical to DA production that is notably absent in red algae that produce the simpler kainoid neurochemical, kainic acid. The biochemical characterization of the N-prenyltransferase (RadA) and kainoid synthase (RadC) enzymes support a slightly altered DA biosynthetic model in C. armata via the congener isodomoic acid B, with RadC behaving more like the homologous diatom enzyme despite higher amino acid similarity to red algal kainic acid synthesis enzymes. A phylogenetic analysis of the rad genes suggests unique origins for the red macroalgal and diatom genes in their respective hosts, with native eukaryotic CYP450 neofunctionalization combining with the horizontal gene transfer of N-prenyltransferases and kainoid synthases to establish DA production within the algal lineages.
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Turk Dermastia T, Dall’Ara S, Dolenc J, Mozetič P. Toxicity of the Diatom Genus Pseudo-nitzschia (Bacillariophyceae): Insights from Toxicity Tests and Genetic Screening in the Northern Adriatic Sea. Toxins (Basel) 2022; 14:toxins14010060. [PMID: 35051037 PMCID: PMC8781606 DOI: 10.3390/toxins14010060] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 01/04/2022] [Accepted: 01/12/2022] [Indexed: 02/05/2023] Open
Abstract
Diatoms of the genus Pseudo-nitzschia H.Peragallo are known to produce domoic acid (DA), a toxin involved in amnesic shellfish poisoning (ASP). Strains of the same species are often classified as both toxic and nontoxic, and it is largely unknown whether this difference is also genetic. In the Northern Adriatic Sea, there are virtually no cases of ASP, but DA occasionally occurs in shellfish samples. So far, three species-P. delicatissima (Cleve) Heiden, P. multistriata (H. Takano) H. Takano, and P. calliantha Lundholm, Moestrup, & Hasle-have been identified as producers of DA in the Adriatic Sea. By means of enzme-linked immunosorbent assay (ELISA), high-performance liquid chromatography with UV and visible spectrum detection (HPLC-UV/VIS), and liquid chromatography with tandem mass spectrometry (LC-MS/MS), we reconfirmed the presence of DA in P. multistriata and P. delicatissima and detect for the first time in the Adriatic Sea DA in P. galaxiae Lundholm, & Moestrup. Furthermore, we attempted to answer the question of the distribution of DA production among Pseudo-nitzschia species and strains by sequencing the internal transcribed spacer (ITS) phylogenetic marker and the dabA DA biosynthesis gene and coupling this with toxicity data. Results show that all subclades of the Pseudo-nitzschia genus contain toxic species and that toxicity appears to be strain dependent, often with geographic partitioning. Amplification of dabA was successful only in toxic strains of P. multistriata and the presence of the genetic architecture for DA production in non-toxic strains was thus not confirmed.
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Affiliation(s)
- Timotej Turk Dermastia
- Marine Biology Station Piran, National Institute of Biology, 6330 Piran, Slovenia;
- International Postgraduate School Jožef Stefan, 1000 Ljubljana, Slovenia
- Correspondence:
| | - Sonia Dall’Ara
- National Reference Laboratory for Marine Biotoxins, Centro Ricerche Marine, 47042 Cesenatico, Italy;
| | - Jožica Dolenc
- Institute of Food Safety, Feed and Environment, Veterinary Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia;
| | - Patricija Mozetič
- Marine Biology Station Piran, National Institute of Biology, 6330 Piran, Slovenia;
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Thi Nhu Bui Q, Kim H, Wang H, Ki JS. Unveiling the genomic structures and evolutionary events of the saxitoxin biosynthetic gene sxtA in the marine toxic dinoflagellate Alexandrium. Mol Phylogenet Evol 2022; 168:107417. [PMID: 35031458 DOI: 10.1016/j.ympev.2022.107417] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 11/24/2021] [Accepted: 12/27/2021] [Indexed: 12/30/2022]
Abstract
Marine dinoflagellates Alexandriumare known to produce saxitoxin (STX) and cause paralytic shellfish poisoning (PSP) which can result in mortality in human. SxtA is considered a core gene for the biosynthesis of STX. However, its gene coding structure and evolutionary history have yet to be fully elucidated. Here, we determined the full-length sequences of sxtA cDNA and genomic coding regions from two toxic dinoflagellates, Alexandrium catenella (LIMS-PS-2645 and LIMS-PS-2647) andA. pacificum (LMBE-C4), characterised their domain structures, and resolved evolutionary events. The sxtA gene was encoded on the genome without introns, and was identical in length (4002 bp) between two A. catenella strains, but their sequences differed from A. pacificum (5031 bp). SxtA consists of four domains, sxtA1, sxtA2, sxtA3, and sxtA4; however, A. pacificum has an extra domain TauD near sxtA1. Each domain had >64.4% GC content, with the highest being 71.6% in sxtA3. Molecular divergence was found to be significantly higher in sxtA4 than in the other domains. Phylogenetic trees of sxtA and separate domains showed that bacteria diverged earliest, followed by non-toxic, toxic cyanobacteria, toxic dinoflagellates. While sxtA domains in Alexandrium were similar to the PKS-like structure with the conserved sxtA1, sxtA2, and sxtA3. PKS_KS may be replaced by sxtA4 in toxic Alexandrium. These suggest that sxtA in Alexandrium may have evolved by acquiring specific domains, whose modification and complexity markedly affect toxin biosynthesis.
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Affiliation(s)
- Quynh Thi Nhu Bui
- Department of Biotechnology, Sangmyung University, Seoul 03016, South Korea
| | - Hansol Kim
- Department of Biotechnology, Sangmyung University, Seoul 03016, South Korea
| | - Hui Wang
- Department of Biotechnology, Sangmyung University, Seoul 03016, South Korea; Hunan Province Key Laboratory of Typical Environmental Pollution and Health Hazards, School of Public Health, University of South China, Hengyang 421001, China
| | - Jang-Seu Ki
- Department of Biotechnology, Sangmyung University, Seoul 03016, South Korea.
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Anestis K, Kohli GS, Wohlrab S, Varga E, Larsen TO, Hansen PJ, John U. Polyketide synthase genes and molecular trade-offs in the ichthyotoxic species Prymnesium parvum. Sci Total Environ 2021; 795:148878. [PMID: 34252778 DOI: 10.1016/j.scitotenv.2021.148878] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 06/18/2021] [Accepted: 07/02/2021] [Indexed: 06/13/2023]
Abstract
Prymnesium parvum is a bloom forming haptophyte that has been responsible for numerous fish kill events across the world. The toxicity of P. parvum has been attributed to the production of large polyketide compounds, collectively called prymnesins, which based on their structure can be divided into A-, B- and C-type. The polyketide chemical nature of prymnesins indicates the potential involvement of polyketide synthases (PKSs) in their biosynthesis. However, little is known about the presence of PKSs in P. parvum as well as the potential molecular trade-offs of toxin biosynthesis. In the current study, we generated and analyzed the transcriptomes of nine P. parvum strains that produce different toxin types and have various cellular toxin contents. Numerous type I PKSs, ranging from 37 to 109, were found among the strains. Larger modular type I PKSs were mainly retrieved from strains with high cellular toxin levels and eight consensus transcripts were present in all nine strains. Gene expression variance analysis revealed potential molecular trade-offs associated with cellular toxin quantity, showing that basic metabolic processes seem to correlate negatively with cellular toxin content. These findings point towards the presence of metabolic costs for maintaining high cellular toxin quantity. The detailed analysis of PKSs in P. parvum is the first step towards better understanding the molecular basis of the biosynthesis of prymnesins and contributes to the development of molecular tools for efficient monitoring of future blooms.
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Affiliation(s)
- Konstantinos Anestis
- Ecological Chemistry, Alfred Wegener Institute for Polar and Marine Research, Am Handelshafen 12, 27570, Bremerhaven, Germany.
| | - Gurjeet Singh Kohli
- Ecological Chemistry, Alfred Wegener Institute for Polar and Marine Research, Am Handelshafen 12, 27570, Bremerhaven, Germany.
| | - Sylke Wohlrab
- Ecological Chemistry, Alfred Wegener Institute for Polar and Marine Research, Am Handelshafen 12, 27570, Bremerhaven, Germany; Helmholtz Institute for Functional Marine Biodiversity, Ammerländer Heerstraße 231, 26129 Oldenburg, Germany.
| | - Elisabeth Varga
- Department of Food Chemistry and Toxicology, Faculty of Chemistry, University of Vienna, Währinger Straße 40, 1090 Vienna, Austria.
| | - Thomas Ostenfeld Larsen
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads 221, 2800 Kongens Lyngby, Denmark.
| | - Per Juel Hansen
- Marine Biology Section, University of Copenhagen, Strandpromenaden 5, 3000 Helsingør, Denmark.
| | - Uwe John
- Ecological Chemistry, Alfred Wegener Institute for Polar and Marine Research, Am Handelshafen 12, 27570, Bremerhaven, Germany; Helmholtz Institute for Functional Marine Biodiversity, Ammerländer Heerstraße 231, 26129 Oldenburg, Germany.
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Chan KKY, Kong HK, Tse SPK, Chan Z, Lo PY, Kwok KWH, Lo SCL. Finding Species-Specific Extracellular Surface-Facing Proteomes in Toxic Dinoflagellates. Toxins (Basel) 2021; 13:624. [PMID: 34564629 PMCID: PMC8473415 DOI: 10.3390/toxins13090624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 08/31/2021] [Accepted: 09/01/2021] [Indexed: 11/27/2022] Open
Abstract
As a sequel to our previous report of the existence of species-specific protein/peptide expression profiles (PEPs) acquired by mass spectrometry in some dinoflagellates, we established, with the help of a plasma-membrane-impermeable labeling agent, a surface amphiesmal protein extraction method (SAPE) to label and capture species-specific surface proteins (SSSPs) as well as saxitoxins-producing-species-specific surface proteins (Stx-SSPs) that face the extracellular space (i.e., SSSPsEf and Stx-SSPsEf). Five selected toxic dinoflagellates, Alexandrium minutum, A. lusitanicum, A. tamarense, Gymnodinium catenatum, and Karenia mikimotoi, were used in this study. Transcriptomic databases of these five species were also constructed. With the aid of liquid chromatography linked-tandem mass spectrometry (LC-MS/MS) and the transcriptomic databases of these species, extracellularly facing membrane proteomes of the five different species were identified. Within these proteomes, 16 extracellular-facing and functionally significant transport proteins were found. Furthermore, 10 SSSPs and 6 Stx-SSPs were identified as amphiesmal proteins but not facing outward to the extracellular environment. We also found SSSPsEf and Stx-SSPsEf in the proteomes. The potential functional correlation of these proteins towards the production of saxitoxins in dinoflagellates and the degree of species specificity were discussed accordingly.
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Affiliation(s)
- Kenrick Kai-yuen Chan
- Department of Applied Biology and Chemical Technology, Faculty of Applied Science and Textiles, The Hong Kong Polytechnic University, Hung Hom, Hong Kong; (K.K.-y.C.); (H.-k.K.); (S.P.-k.T.); (Z.C.); (P.-y.L.); (K.W.H.K.)
| | - Hang-kin Kong
- Department of Applied Biology and Chemical Technology, Faculty of Applied Science and Textiles, The Hong Kong Polytechnic University, Hung Hom, Hong Kong; (K.K.-y.C.); (H.-k.K.); (S.P.-k.T.); (Z.C.); (P.-y.L.); (K.W.H.K.)
- Research Institute for Future Food, The Hong Kong Polytechnic University, Hung Hom, Hong Kong
| | - Sirius Pui-kam Tse
- Department of Applied Biology and Chemical Technology, Faculty of Applied Science and Textiles, The Hong Kong Polytechnic University, Hung Hom, Hong Kong; (K.K.-y.C.); (H.-k.K.); (S.P.-k.T.); (Z.C.); (P.-y.L.); (K.W.H.K.)
| | - Zoe Chan
- Department of Applied Biology and Chemical Technology, Faculty of Applied Science and Textiles, The Hong Kong Polytechnic University, Hung Hom, Hong Kong; (K.K.-y.C.); (H.-k.K.); (S.P.-k.T.); (Z.C.); (P.-y.L.); (K.W.H.K.)
| | - Pak-yeung Lo
- Department of Applied Biology and Chemical Technology, Faculty of Applied Science and Textiles, The Hong Kong Polytechnic University, Hung Hom, Hong Kong; (K.K.-y.C.); (H.-k.K.); (S.P.-k.T.); (Z.C.); (P.-y.L.); (K.W.H.K.)
| | - Kevin W. H. Kwok
- Department of Applied Biology and Chemical Technology, Faculty of Applied Science and Textiles, The Hong Kong Polytechnic University, Hung Hom, Hong Kong; (K.K.-y.C.); (H.-k.K.); (S.P.-k.T.); (Z.C.); (P.-y.L.); (K.W.H.K.)
- Research Institute for Future Food, The Hong Kong Polytechnic University, Hung Hom, Hong Kong
| | - Samuel Chun-lap Lo
- Department of Applied Biology and Chemical Technology, Faculty of Applied Science and Textiles, The Hong Kong Polytechnic University, Hung Hom, Hong Kong; (K.K.-y.C.); (H.-k.K.); (S.P.-k.T.); (Z.C.); (P.-y.L.); (K.W.H.K.)
- Research Institute for Future Food, The Hong Kong Polytechnic University, Hung Hom, Hong Kong
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12
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Akbar MA, Yusof NYM, Sahrani FK, Usup G, Ahmad A, Baharum SN, Muhammad NAN, Bunawan H. Insights into Alexandrium minutum Nutrient Acquisition, Metabolism and Saxitoxin Biosynthesis through Comprehensive Transcriptome Survey. Biology (Basel) 2021; 10:826. [PMID: 34571703 DOI: 10.3390/biology10090826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 08/12/2021] [Accepted: 08/13/2021] [Indexed: 11/17/2022]
Abstract
Simple Summary Alexandrium minutum is one of the causing organisms for the occurrence of harmful algae bloom (HABs) in marine ecosystems. This species produces saxitoxin, one of the deadliest neurotoxins which can cause human mortality. However, molecular information such as genes and proteins catalog on this species is still lacking. Therefore, this study has successfully characterized several new molecular mechanisms regarding A. minutum environmental adaptation and saxitoxin biosynthesis. Ultimately, this study provides a valuable resource for facilitating future dinoflagellates’ molecular response to environmental changes. Abstract The toxin-producing dinoflagellate Alexandrium minutum is responsible for the outbreaks of harmful algae bloom (HABs). It is a widely distributed species and is responsible for producing paralytic shellfish poisoning toxins. However, the information associated with the environmental adaptation pathway and toxin biosynthesis in this species is still lacking. Therefore, this study focuses on the functional characterization of A. minutum unigenes obtained from transcriptome sequencing using the Illumina Hiseq 4000 sequencing platform. A total of 58,802 (47.05%) unigenes were successfully annotated using public databases such as NCBI-Nr, UniprotKB, EggNOG, KEGG, InterPRO and Gene Ontology (GO). This study has successfully identified key features that enable A. minutum to adapt to the marine environment, including several carbon metabolic pathways, assimilation of various sources of nitrogen and phosphorus. A. minutum was found to encode homologues for several proteins involved in saxitoxin biosynthesis, including the first three proteins in the pathway of saxitoxin biosynthesis, namely sxtA, sxtG and sxtB. The comprehensive transcriptome analysis presented in this study represents a valuable resource for understanding the dinoflagellates molecular metabolic model regarding nutrient acquisition and biosynthesis of saxitoxin.
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Kim H, Park H, Wang H, Yoo HY, Park J, Ki JS. Low Temperature and Cold Stress Significantly Increase Saxitoxins (STXs) and Expression of STX Biosynthesis Genes sxtA4 and sxtG in the Dinoflagellate Alexandrium catenella. Mar Drugs 2021; 19:291. [PMID: 34064031 PMCID: PMC8224010 DOI: 10.3390/md19060291] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 05/18/2021] [Accepted: 05/18/2021] [Indexed: 12/22/2022] Open
Abstract
Toxic dinoflagellate Alexandrium spp. produce saxitoxins (STXs), whose biosynthesis pathway is affected by temperature. However, the link between the regulation of the relevant genes and STXs' accumulation and temperature is insufficiently understood. In the present study, we evaluated the effects of temperature on cellular STXs and the expression of two core STX biosynthesis genes (sxtA4 and sxtG) in the toxic dinoflagellate Alexandrium catenella Alex03 isolated from Korean waters. We analyzed the growth rate, toxin profiles, and gene responses in cells exposed to different temperatures, including long-term adaptation (12, 16, and 20 °C) and cold and heat stresses. Temperature significantly affected the growth of A. catenella, with optimal growth (0.49 division/day) at 16 °C and the largest cell size (30.5 µm) at 12 °C. High concentration of STXs eq were detected in cells cultured at 16 °C (86.3 fmol/cell) and exposed to cold stress at 20→12 °C (96.6 fmol/cell) compared to those at 20 °C and exposed to heat stress. Quantitative real-time PCR (qRT-PCR) revealed significant gene expression changes of sxtA4 in cells cultured at 16 °C (1.8-fold) and cold shock at 20→16 °C (9.9-fold). In addition, sxtG was significantly induced in cells exposed to cold shocks (20→16 °C; 19.5-fold) and heat stress (12→20 °C; 25.6-fold). Principal component analysis (PCA) revealed that low temperature (12 and 16 °C) and cold stress were positively related with STXs' production and gene expression levels. These results suggest that temperature may affect the toxicity and regulation of STX biosynthesis genes in dinoflagellates.
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Affiliation(s)
- Hansol Kim
- Department of Biotechnology, Sangmyung University, Seoul 03016, Korea; (H.K.); (H.P.); (H.W.); (H.Y.Y.)
| | - Hyunjun Park
- Department of Biotechnology, Sangmyung University, Seoul 03016, Korea; (H.K.); (H.P.); (H.W.); (H.Y.Y.)
| | - Hui Wang
- Department of Biotechnology, Sangmyung University, Seoul 03016, Korea; (H.K.); (H.P.); (H.W.); (H.Y.Y.)
| | - Hah Young Yoo
- Department of Biotechnology, Sangmyung University, Seoul 03016, Korea; (H.K.); (H.P.); (H.W.); (H.Y.Y.)
| | - Jaeyeon Park
- Environment and Resource Convergence Center, Advanced Institute of Convergence Technologies, Suwon 16229, Korea
| | - Jang-Seu Ki
- Department of Biotechnology, Sangmyung University, Seoul 03016, Korea; (H.K.); (H.P.); (H.W.); (H.Y.Y.)
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Cusick KD, Widder EA. Bioluminescence and toxicity as driving factors in harmful algal blooms: Ecological functions and genetic variability. Harmful Algae 2020; 98:101850. [PMID: 33129462 DOI: 10.1016/j.hal.2020.101850] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2019] [Revised: 05/29/2020] [Accepted: 06/02/2020] [Indexed: 06/11/2023]
Abstract
Dinoflagellates are an ecologically important group of marine microbial eukaryotes with a remarkable array of adaptive strategies. It is ironic that two of the traits for which dinoflagellates are best known, toxin production and bioluminescence, are rarely linked when considering the ecological significance of either. Although dinoflagellate species that form some of the most widespread and frequent harmful algal blooms (HABs) are bioluminescent, the molecular and eco-evolutionary associations between these two traits has received little attention. Here, the major themes of biochemistry and genetics, ecological functions, signaling mechanisms, and evolution are addressed, with parallels and connections drawn between the two. Of the 17 major classes of dinoflagellate toxins, only two are produced by bioluminescent species: saxitoxin (STX) and yessotoxin. Of these, STX has been extensively studied, including the identification of the STX biosynthetic genes. While numerous theories have been put forward as to the eco-evolutionary roles of both bioluminescence and toxicity, a general consensus is that both function as grazing deterrents. Thus, both bioluminescence and toxicity may aid in HAB initiation as they alleviate grazing pressure on the HAB species. A large gap in our understanding is the genetic variability among natural bloom populations, as both toxic and non-toxic strains have been isolated from the same geographic location. The same applies to bioluminescence, as there exist both bioluminescent and non-bioluminescent strains of the same species. Recent evidence demonstrating that blooms are not monoclonal events necessitates a greater level of understanding as to the genetic variability of these traits among sub-populations as well as the mechanisms by which cells acquire or lose the trait, as sequence analysis of STX+ and STX- species indicate the key gene required for toxicity is lost rather than gained. While the extent of genetic variability for both bioluminescence and toxicity among natural HAB sub-populations remains unknown, it is an area that needs to be explored in order to gain greater insights into the molecular mechanisms and environmental parameters driving HAB evolution.
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Affiliation(s)
- Kathleen D Cusick
- University of Maryland Baltimore County, Department of Biological Sciences, 1000 Hilltop Circle, Baltimore, MD 21250, United States.
| | - Edith A Widder
- Ocean Research and Conservation Association, 1420 Seaway Dr, Fort Pierce, FL 34949, United States.
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15
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Vico P, Bonilla S, Cremella B, Aubriot L, Iriarte A, Piccini C. Biogeography of the cyanobacterium Raphidiopsis (Cylindrospermopsis) raciborskii: Integrating genomics, phylogenetic and toxicity data. Mol Phylogenet Evol 2020; 148:106824. [PMID: 32294544 DOI: 10.1016/j.ympev.2020.106824] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 02/07/2020] [Accepted: 04/07/2020] [Indexed: 12/18/2022]
Abstract
Raphidiopsis (Cylindrospermopsis) raciborskii, a globally distributed bloom-forming cyanobacterium, produces either the cytotoxin cylindrospermopsin (CYL) in Oceania, Asia and Europe or the neurotoxin saxitoxin (STX) and analogues (paralytic shellfish poison, PSP) in South America (encoded by sxt genetic cluster) and none of them in Africa. Nevertheless, this particular geographic pattern is usually overlooked in current hypotheses about the species dispersal routes. Here, we combined genomics, phylogenetic analyses, toxicity data and a literature survey to unveil the evolutionary history and spread of the species. Phylogenies based on 354 orthologous genes from all the available genomes and ribosomal ITS sequences of the taxon showed two well-defined clades: the American, having the PSP producers; and the Oceania/Europe/Asia, including the CYL producers. We propose central Africa as the original dispersion center (non-toxic populations), reaching North Africa and North America (in former Laurasia continent). The ability to produce CYL probably took place in populations that advanced to sub-Saharan Africa and then to Oceania and South America. According to the genomic context of the sxt cluster found in PSP-producer strains, this trait was acquired once by horizontal transfer in South America, where the ability to produce CYL was lost.
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Affiliation(s)
- Paula Vico
- Departamento de Microbiología, Instituto de Investigaciones Biológicas Clemente Estable, Avenida Italia 3318, 11600 Montevideo, Uruguay; Laboratorio de Biología Computacional, Departamento de Desarrollo Biotecnológico, Instituto de Higiene, Facultad de Medicina, Avenida A. Navarro 3051, 11600 Montevideo, Uruguay
| | - Sylvia Bonilla
- Sección Limnología, Instituto de Ecología y Ciencias Ambientales. Facultad de Ciencias. Universidad de la República, Iguá 4225, 11400 Montevideo, Uruguay; Physiology and Ecology Phytoplankton Group, CSIC, Uruguay
| | - Bruno Cremella
- Sección Limnología, Instituto de Ecología y Ciencias Ambientales. Facultad de Ciencias. Universidad de la República, Iguá 4225, 11400 Montevideo, Uruguay; Physiology and Ecology Phytoplankton Group, CSIC, Uruguay; Laboratory of Environmental Analysis, Université de Sherbrooke, Sherbrooke, Quebec, Canada
| | - Luis Aubriot
- Sección Limnología, Instituto de Ecología y Ciencias Ambientales. Facultad de Ciencias. Universidad de la República, Iguá 4225, 11400 Montevideo, Uruguay; Physiology and Ecology Phytoplankton Group, CSIC, Uruguay
| | - Andrés Iriarte
- Laboratorio de Biología Computacional, Departamento de Desarrollo Biotecnológico, Instituto de Higiene, Facultad de Medicina, Avenida A. Navarro 3051, 11600 Montevideo, Uruguay.
| | - Claudia Piccini
- Departamento de Microbiología, Instituto de Investigaciones Biológicas Clemente Estable, Avenida Italia 3318, 11600 Montevideo, Uruguay.
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Wang H, Guo R, Lim WA, Allen AE, Ki JS. Comparative transcriptomics of toxin synthesis genes between the non-toxin producing dinoflagellate Cochlodinium polykrikoides and toxigenic Alexandrium pacificum. Harmful Algae 2020; 93:101777. [PMID: 32307068 DOI: 10.1016/j.hal.2020.101777] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Revised: 02/13/2020] [Accepted: 02/19/2020] [Indexed: 06/11/2023]
Abstract
In the present study, we extensively characterized potential toxin-related genes, including polyketide synthase (PKS), saxitoxin (STX) and fatty acid synthase (FAS) from the non-toxin producing marine dinoflagellate Cochlodinium polykrikoides, comparing to those of a toxigenic dinoflagellate Alexandrium pacificum. RNA sequencing revealed 50 and 271 PKS contigs from C. polykrikoides and A. pacificum, respectively. According to domain constitute and amino acid alteration, we further classified the dinoflagellate type I PKS genes into 4 sub-groups. Type III PKS was first identified in C. polykrikoides. Interestingly, we detected a large number (242 and 288) of homologs of 18 sxt genes from two studied dinoflagellates. Most of the eight key genes (sxtA, sxtB, sxtD, sxtG, sxtH/T, sxtI, sxtS and sxtU) for STX synthesis were detected in both dinoflatellates, whereas a core STX biosynthesis gene sxtG was not detected in C. polykrikoides. This may partially explain the absence of saxitoxin production in C. polykrikoides. In addition, we identified several type I and type II FAS genes, including FabD, FabF, FabG, FabH, FabI, and FabZ, whereas FabB was not found in C. polykrikoides. Overall, the numbers of the toxin-related genes in C. polykrikoides were less than that of A. pacificum. Phylogenetic analyses showed that type I PKS/FASs of dinoflagellates had close relationships with apicomplexans and bacteria. These suggest that the toxin-related PKS and sxt genes are commonly present in toxigenic and non-toxin producing dinoflagellates, and may be involved not only in the toxin synthesis, but also in other related molecular metabolic functions.
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Affiliation(s)
- Hui Wang
- Department of Biotechnology, Sangmyung University, Seoul 03016, South Korea
| | - Ruoyu Guo
- Department of Biotechnology, Sangmyung University, Seoul 03016, South Korea; Key Laboratory of Marine Ecosystem and Biogeochemistry, State Oceanic Administration & Second Institute of Oceanography, Ministry of Natural Resources, PR China
| | - Weol-Ae Lim
- Ocean Climate and Ecology Research Division, National Institute of Fisheries Science (NIFS), Busan 46083, South Korea
| | - Andrew E Allen
- Scripps Institution of Oceanography, University of California, San Diego, CA 92093, USA; Microbial and Environmental Genomics Group, J. Craig Venter Institute, La Jolla, CA 92037, USA
| | - Jang-Seu Ki
- Department of Biotechnology, Sangmyung University, Seoul 03016, South Korea.
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Akbar MA, Mohd Yusof NY, Tahir NI, Ahmad A, Usup G, Sahrani FK, Bunawan H. Biosynthesis of Saxitoxin in Marine Dinoflagellates: An Omics Perspective. Mar Drugs 2020; 18:md18020103. [PMID: 32033403 PMCID: PMC7073992 DOI: 10.3390/md18020103] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 01/09/2020] [Accepted: 01/09/2020] [Indexed: 02/07/2023] Open
Abstract
Saxitoxin is an alkaloid neurotoxin originally isolated from the clam Saxidomus giganteus in 1957. This group of neurotoxins is produced by several species of freshwater cyanobacteria and marine dinoflagellates. The saxitoxin biosynthesis pathway was described for the first time in the 1980s and, since then, it was studied in more than seven cyanobacterial genera, comprising 26 genes that form a cluster ranging from 25.7 kb to 35 kb in sequence length. Due to the complexity of the genomic landscape, saxitoxin biosynthesis in dinoflagellates remains unknown. In order to reveal and understand the dynamics of the activity in such impressive unicellular organisms with a complex genome, a strategy that can carefully engage them in a systems view is necessary. Advances in omics technology (the collective tools of biological sciences) facilitated high-throughput studies of the genome, transcriptome, proteome, and metabolome of dinoflagellates. The omics approach was utilized to address saxitoxin-producing dinoflagellates in response to environmental stresses to improve understanding of dinoflagellates gene–environment interactions. Therefore, in this review, the progress in understanding dinoflagellate saxitoxin biosynthesis using an omics approach is emphasized. Further potential applications of metabolomics and genomics to unravel novel insights into saxitoxin biosynthesis in dinoflagellates are also reviewed.
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Affiliation(s)
- Muhamad Afiq Akbar
- School of Bioscience and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi 43600, Malaysia;
| | - Nurul Yuziana Mohd Yusof
- Department of Earth Science and Environment, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi 43600, Malaysia; (N.Y.M.Y.); (F.K.S.)
| | - Noor Idayu Tahir
- Malaysian Palm Oil Board, No 6, Persiaran Institusi, Bandar Baru Bangi, Kajang 43000, Selangor, Malaysia;
| | - Asmat Ahmad
- University College Sabah Foundation, Jalan Sanzac, Kota Kinabalu 88100, Sabah, Malaysia; (A.A.); (G.U.)
| | - Gires Usup
- University College Sabah Foundation, Jalan Sanzac, Kota Kinabalu 88100, Sabah, Malaysia; (A.A.); (G.U.)
| | - Fathul Karim Sahrani
- Department of Earth Science and Environment, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi 43600, Malaysia; (N.Y.M.Y.); (F.K.S.)
| | - Hamidun Bunawan
- Institute of Systems Biology, Universiti Kebangsaan Malaysia, Bangi 43600, Malaysia
- Correspondence: ; Tel.: +60-389-214-546
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18
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Fewer DP, Metsä‐Ketelä M. A pharmaceutical model for the molecular evolution of microbial natural products. FEBS J 2019; 287:1429-1449. [DOI: 10.1111/febs.15129] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 10/11/2019] [Accepted: 11/05/2019] [Indexed: 12/20/2022]
Affiliation(s)
- David P. Fewer
- Department of Microbiology University of Helsinki Finland
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19
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Carvalho IL, Pelerito A, Ribeiro I, Cordeiro R, Núncio MS, Vale P. Paralytic shellfish poisoning due to ingestion of contaminated mussels: A 2018 case report in Caparica (Portugal). Toxicon X 2019; 4:100017. [PMID: 32550574 DOI: 10.1016/j.toxcx.2019.100017] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Revised: 08/01/2019] [Accepted: 09/25/2019] [Indexed: 11/03/2022] Open
Abstract
In Portugal, the potent paralytic shellfish toxins (PSTs) have appeared irregularly since the onset of a national monitoring program for marine biotoxins in 1986. In years where high contamination levels were attained in bivalves, sporadic cases of human poisonings have been recorded, as in 1994 and 2007. The reappearance of high contamination levels led to the appearance of new cases during the autumn of 2018. This study details toxin ingestion, symptomatology and toxin elimination and metabolization in the fluids of two patients, who ingested mussels from the Portuguese southwest coast and required hospitalization due to the severity of symptoms. Toxin elimination was confirmed by ELISA in plasma and urine samples. In mussel samples, the toxin profile obtained by HPLC-FLD displayed a wide diversity of toxins, typical of Gymnodinum catenatum ingestion. However, in the urine samples, the toxin profile was reduced to B1 and dcSTX. Abundant compounds in mussels having an O-sulphate at C11, such as C1+2 and dcGTX2+3, were absent in urine. In plasma, PSTs were not detected by HPLC-FLD. Calculated toxin ingestion, resulting from consumption of an estimated 200-g portion, was in the range of 104–120 μg STX eq./kg b. w. Since 1986 Gymnodinium catenatum contaminates irregularly bivalves in Portugal with PSTs. Acute neurological symptomology, such as paraesthesias, has often required hospitalization. During an episode in October 2018, toxins in fluids of two victims and toxin ingestion were studied. Preliminary confirmation was done by ELISA in serum and urine. PSP toxins with an O-sulphate at C11, abundant in mussels, were absent in urine.
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Cullen A, Pearson LA, Mazmouz R, Liu T, Soeriyadi AH, Ongley SE, Neilan BA. Heterologous expression and biochemical characterisation of cyanotoxin biosynthesis pathways. Nat Prod Rep 2019; 36:1117-1136. [DOI: 10.1039/c8np00063h] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This review discusses cyanotoxin biosynthetic pathways and highlights the heterologous expression and biochemical studies used to characterise them.
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Affiliation(s)
- Alescia Cullen
- School of Environmental and Life Sciences
- University of Newcastle
- Callaghan 2308
- Australia
| | - Leanne A. Pearson
- School of Environmental and Life Sciences
- University of Newcastle
- Callaghan 2308
- Australia
| | - Rabia Mazmouz
- School of Environmental and Life Sciences
- University of Newcastle
- Callaghan 2308
- Australia
| | - Tianzhe Liu
- School of Biotechnology and Biomolecular Sciences
- The University of New South Wales
- Sydney 2052
- Australia
| | - Angela H. Soeriyadi
- School of Biotechnology and Biomolecular Sciences
- The University of New South Wales
- Sydney 2052
- Australia
| | - Sarah E. Ongley
- School of Environmental and Life Sciences
- University of Newcastle
- Callaghan 2308
- Australia
| | - Brett A. Neilan
- School of Environmental and Life Sciences
- University of Newcastle
- Callaghan 2308
- Australia
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21
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Vale P. Impact of light quality and space weather in Alexandrium catenella (Dinophyceae) cultures. Life Sci Space Res (Amst) 2018; 19:1-12. [PMID: 30482275 DOI: 10.1016/j.lssr.2018.07.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Revised: 06/29/2018] [Accepted: 07/27/2018] [Indexed: 06/09/2023]
Abstract
The chain-forming dinoflagellate Alexandrium catenella was grown with LED or fluorescent light. With LED light, the pool of mycosporine-like amino acids (MAAs) with strong antioxidant properties, such as mycosporine-glycine and palythene, was reduced in comparison to fluorescent light. The conjugated MAAs M-320 and M-335/360 presented similar stability to light and oxidation than their respective more sensitive moiety: mycosporine-glycine and palythene, respectively. A. catenella was exposed to extracellular hydrogen peroxide under LED or fluorescent light. It triggered an increase in chain formation at a final concentration of 98 and 196 µM, typical of an inverted U-shaped hormetic response, and reduced cell survival above 294 µM. LED light, minimizing UV-stress photoprotection, was chosen to render cells more susceptible to space weather. Cultures were exposed to 490 µM H2O2 multiple times between November 2017 and February 2018, close to the minimum of solar cycle 24. Cell survival was dependent on temperature, geomagnetic activity, solar X-rays and neutron flux. Geomagnetic activity originated an inverted U-shaped survival curve and X-ray flux a J-shaped survival curve, this second type of hormetic response being more rarely found. The percentage of cells in chains increased moderately with temperature, and more significantly with solar X-ray flux. Chain formation reduced along culture growth, but these observations were dependent on the occurring X-ray flux.
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Affiliation(s)
- Paulo Vale
- The Portuguese Sea and Atmosphere Institute, I.P. (IPMA, IP), Sea and Marine Resources Department (DMRM), R. Alfredo Magalhães Ramalho, 6, Lisbon 1495-006, Portugal.
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Abstract
Drug resistance, especially antibiotic resistance, is a growing threat to human health. To overcome this problem, it is significant to know precisely the mechanisms of drug resistance and/or self-resistance in various kingdoms, from bacteria through plants to animals, once more. This review compares the molecular mechanisms of the resistance against phycotoxins, toxins from marine and terrestrial animals, plants and fungi, and antibiotics. The results reveal that each kingdom possesses the characteristic features. The main mechanisms in each kingdom are transporters/efflux pumps in phycotoxins, mutation and modification of targets and sequestration in marine and terrestrial animal toxins, ABC transporters and sequestration in plant toxins, transporters in fungal toxins, and various or mixed mechanisms in antibiotics. Antibiotic producers in particular make tremendous efforts for avoiding suicide, and are more flexible and adaptable to the changes of environments. With these features in mind, potential alternative strategies to overcome these resistance problems are discussed. This paper will provide clues for solving the issues of drug resistance.
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Affiliation(s)
- Hiroshi Ogawara
- HO Bio Institute, Yushima-2, Bunkyo-ku, Tokyo 113-0034, Japan.
- Department of Biochemistry, Meiji Pharmaceutical University, Noshio-2, Kiyose, Tokyo 204-8588, Japan.
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Humisto A, Jokela J, Liu L, Wahlsten M, Wang H, Permi P, Machado JP, Antunes A, Fewer DP, Sivonen K. The Swinholide Biosynthesis Gene Cluster from a Terrestrial Cyanobacterium, Nostoc sp. Strain UHCC 0450. Appl Environ Microbiol 2018; 84:e02321-17. [PMID: 29150506 DOI: 10.1128/AEM.02321-17] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Accepted: 11/03/2017] [Indexed: 12/02/2022] Open
Abstract
Swinholides are 42-carbon ring polyketides with a 2-fold axis of symmetry. They are potent cytotoxins that disrupt the actin cytoskeleton. Swinholides were discovered from the marine sponge Theonella sp. and were long suspected to be produced by symbiotic bacteria. Misakinolide, a structural variant of swinholide, was recently demonstrated to be the product of a symbiotic heterotrophic proteobacterium. Here, we report the production of swinholide A by an axenic strain of the terrestrial cyanobacterium Nostoc sp. strain UHCC 0450. We located the 85-kb trans-AT polyketide synthase (PKS) swinholide biosynthesis gene cluster from a draft genome of Nostoc sp. UHCC 0450. The swinholide and misakinolide biosynthesis gene clusters share an almost identical order of catalytic domains, with 85% nucleotide sequence identity, and they group together in phylogenetic analysis. Our results resolve speculation around the true producer of swinholides and demonstrate that bacteria belonging to two distantly related phyla both produce structural variants of the same natural product. In addition, we described a biosynthesis cluster from Anabaena sp. strain UHCC 0451 for the synthesis of the cytotoxic and antifungal scytophycin. All of these biosynthesis gene clusters were closely related to each other and created a group of cytotoxic macrolide compounds produced by trans-AT PKSs of cyanobacteria and proteobacteria. IMPORTANCE Many of the drugs in use today originate from natural products. New candidate compounds for drug development are needed due to increased drug resistance. An increased knowledge of the biosynthesis of bioactive compounds can be used to aid chemical synthesis to produce novel drugs. Here, we show that a terrestrial axenic culture of Nostoc cyanobacterium produces swinholides, which have been previously found only from marine sponge or samples related to them. Swinholides are polyketides with a 2-fold axis of symmetry, and they are potent cytotoxins that disrupt the actin cytoskeleton. We describe the biosynthesis gene clusters of swinholide from Nostoc cyanobacteria, as well as the related cytotoxic and antifungal scytophycin from Anabaena cyanobacteria, and we study the evolution of their trans-AT polyketide synthases. Interestingly, swinholide is closely related to misakinolide produced by a symbiotic heterotrophic proteobacterium, demonstrating that bacteria belonging to two distantly related phyla and different habitats can produce similar natural products.
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Saha M, Goecke F, Bhadury P. Minireview: algal natural compounds and extracts as antifoulants. J Appl Phycol 2017; 30:1859-1874. [PMID: 29899600 PMCID: PMC5982446 DOI: 10.1007/s10811-017-1322-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2017] [Revised: 10/17/2017] [Accepted: 10/17/2017] [Indexed: 05/02/2023]
Abstract
Marine biofouling is a paramount phenomenon in the marine environment and causes serious problems to maritime industries worldwide. Marine algae are known to produce a wide variety of chemical compounds with antibacterial, antifungal, antialgal, and anti-macrofouling properties, inhibiting the settlement and growth of other marine fouling organisms. Significant investigations and progress have been made in this field in the last two decades and several antifouling extracts and compounds have been isolated from micro- and macroalgae. In this minireview, we have summarized and evaluated antifouling compounds isolated and identified from macroalgae and microalgae between January 2010 and June 2016. Future directions for their commercialization through metabolic engineering and industrial scale up have been discussed. Upon comparing biogeographical regions, investigations from Southeast Asian waters were found to be rather scarce. Thus, we have also discussed the need to conduct more chemical ecology based research in relatively less explored areas with high algal biodiversity like Southeast Asia.
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Affiliation(s)
- Mahasweta Saha
- Benthic Ecology, Helmholtz Center for Ocean Research, Düsternbrooker weg, 24105 Kiel, Germany
- Present Address: School of Biological Science, University of Essex, Colchester, CO 43 SQ, UK
| | - Franz Goecke
- Department of Plant and Environmental Science (IPV), Norwegian University of Life Sciences (NMBU), Ås, Norway
| | - Punyasloke Bhadury
- Integrative Taxonomy and Microbial Ecology Research Group, Department of Biological Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, Nadia, West Bengal 741246 India
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25
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Durán-Riveroll LM, Cembella AD. Guanidinium Toxins and Their Interactions with Voltage-Gated Sodium Ion Channels. Mar Drugs 2017; 15:E303. [PMID: 29027912 PMCID: PMC5666411 DOI: 10.3390/md15100303] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Revised: 09/14/2017] [Accepted: 09/27/2017] [Indexed: 12/19/2022] Open
Abstract
Guanidinium toxins, such as saxitoxin (STX), tetrodotoxin (TTX) and their analogs, are naturally occurring alkaloids with divergent evolutionary origins and biogeographical distribution, but which share the common chemical feature of guanidinium moieties. These guanidinium groups confer high biological activity with high affinity and ion flux blockage capacity for voltage-gated sodium channels (NaV). Members of the STX group, known collectively as paralytic shellfish toxins (PSTs), are produced among three genera of marine dinoflagellates and about a dozen genera of primarily freshwater or brackish water cyanobacteria. In contrast, toxins of the TTX group occur mainly in macrozoa, particularly among puffer fish, several species of marine invertebrates and a few terrestrial amphibians. In the case of TTX and analogs, most evidence suggests that symbiotic bacteria are the origin of the toxins, although endogenous biosynthesis independent from bacteria has not been excluded. The evolutionary origin of the biosynthetic genes for STX and analogs in dinoflagellates and cyanobacteria remains elusive. These highly potent molecules have been the subject of intensive research since the latter half of the past century; first to study the mode of action of their toxigenicity, and later as tools to characterize the role and structure of NaV channels, and finally as therapeutics. Their pharmacological activities have provided encouragement for their use as therapeutants for ion channel-related pathologies, such as pain control. The functional role in aquatic and terrestrial ecosystems for both groups of toxins is unproven, although plausible mechanisms of ion channel regulation and chemical defense are often invoked. Molecular approaches and the development of improved detection methods will yield deeper understanding of their physiological and ecological roles. This knowledge will facilitate their further biotechnological exploitation and point the way towards development of pharmaceuticals and therapeutic applications.
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Affiliation(s)
- Lorena M Durán-Riveroll
- CONACYT-Instituto de Ciencias del Mary Limnología, Universidad Nacional Autónoma de México, Mexico 04510, Mexico.
| | - Allan D Cembella
- Alfred-Wegener-Institut, Helmholtz Zentrum für Polar-und Meeresforschung, 27570 Bremerhaven, Germany.
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Vale P. Resistance to Hydrogen Peroxide Highlights Gymnodinium catenatum (Dinophyceae) Sensitivity to Geomagnetic Activity. Photochem Photobiol 2017; 94:95-104. [PMID: 28763102 DOI: 10.1111/php.12815] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Accepted: 07/15/2017] [Indexed: 11/26/2022]
Abstract
The chain-forming dinoflagellate Gymnodinium catenatum was exposed to hydrogen peroxide. Microscopical examination revealed striking dose-response alterations in chain formation above 245 μm: singlets replaced the dominance of long chain formations. These observations were valid for cells acclimated to halogen light. Under fluorescent light, cells were more resistant to modifications in chain length after H2 O2 exposure. Growth along 9 h in the presence of extracellular H2 O2 followed an hormesis response in both light regimes. Under halogen light conditions, alterations in chain formation and net growth were related to culture time, inocula concentration and geomagnetic activity (GMA) in the proceeding hours. Below a 16 nT threshold in GMA average growth was 0%, while above 16 nT it was circa +9%, independently if the local static magnetic field was altered by a permanent magnet or not. Mycosporine-like amino acids that can have an antioxidant role and are easily oxidized decreased from 7.1 to 6.5 pg cell-1 (P < 0.05) under halogen light and exposure to 245 μm H2 O2 . GMA, as well as UV-A, increased stress responsiveness that can momentarily protect cells from extracellular H2 O2 addition. However, stress response is dependent on bio-availability of several micronutrients and macronutrients, many found at limiting concentrations in oceanic waters.
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Affiliation(s)
- Paulo Vale
- Sea and Marine Resources Department (DMRM), The Portuguese Sea and Atmosphere Institute, I.P. (IPMA, IP), Lisbon, Portugal
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Abstract
Covering: July 2012 to June 2015. Previous review: Nat. Prod. Rep., 2013, 30, 869-915The structurally diverse imidazole-, oxazole-, and thiazole-containing secondary metabolites are widely distributed in terrestrial and marine environments, and exhibit extensive pharmacological activities. In this review the latest progress involving the isolation, biological activities, and chemical and biogenetic synthesis studies on these natural products has been summarized.
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Affiliation(s)
- Zhong Jin
- State Key Laboratory and Institute of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, China. and Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300071, China
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Tsuchiya S, Cho Y, Yoshioka R, Konoki K, Nagasawa K, Oshima Y, Yotsu-Yamashita M. Synthesis and Identification of Key Biosynthetic Intermediates for the Formation of the Tricyclic Skeleton of Saxitoxin. Angew Chem Int Ed Engl 2017; 56:5327-5331. [DOI: 10.1002/anie.201612461] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Indexed: 11/09/2022]
Affiliation(s)
- Shigeki Tsuchiya
- Graduate School of Agricultural Science; Tohoku University; 468-1 Aramaki-Aza-Aoba, Aoba-ku Sendai 980-0845 Japan
| | - Yuko Cho
- Graduate School of Agricultural Science; Tohoku University; 468-1 Aramaki-Aza-Aoba, Aoba-ku Sendai 980-0845 Japan
| | - Renpei Yoshioka
- Graduate School of Agricultural Science; Tohoku University; 468-1 Aramaki-Aza-Aoba, Aoba-ku Sendai 980-0845 Japan
| | - Keiichi Konoki
- Graduate School of Agricultural Science; Tohoku University; 468-1 Aramaki-Aza-Aoba, Aoba-ku Sendai 980-0845 Japan
| | - Kazuo Nagasawa
- Faculty of Technology; Tokyo University of Agriculture and Technology; 2-24-16 Naka-cho, Koganei-shi Tokyo 184-8588 Japan
| | - Yasukatsu Oshima
- Graduate School of Life Sciences; Tohoku University; 2-1-1 Katahira, Aoba-ku Sendai 980-8577 Japan
| | - Mari Yotsu-Yamashita
- Graduate School of Agricultural Science; Tohoku University; 468-1 Aramaki-Aza-Aoba, Aoba-ku Sendai 980-0845 Japan
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29
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Tsuchiya S, Cho Y, Yoshioka R, Konoki K, Nagasawa K, Oshima Y, Yotsu-Yamashita M. Synthesis and Identification of Key Biosynthetic Intermediates for the Formation of the Tricyclic Skeleton of Saxitoxin. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201612461] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Affiliation(s)
- Shigeki Tsuchiya
- Graduate School of Agricultural Science; Tohoku University; 468-1 Aramaki-Aza-Aoba, Aoba-ku Sendai 980-0845 Japan
| | - Yuko Cho
- Graduate School of Agricultural Science; Tohoku University; 468-1 Aramaki-Aza-Aoba, Aoba-ku Sendai 980-0845 Japan
| | - Renpei Yoshioka
- Graduate School of Agricultural Science; Tohoku University; 468-1 Aramaki-Aza-Aoba, Aoba-ku Sendai 980-0845 Japan
| | - Keiichi Konoki
- Graduate School of Agricultural Science; Tohoku University; 468-1 Aramaki-Aza-Aoba, Aoba-ku Sendai 980-0845 Japan
| | - Kazuo Nagasawa
- Faculty of Technology; Tokyo University of Agriculture and Technology; 2-24-16 Naka-cho, Koganei-shi Tokyo 184-8588 Japan
| | - Yasukatsu Oshima
- Graduate School of Life Sciences; Tohoku University; 2-1-1 Katahira, Aoba-ku Sendai 980-8577 Japan
| | - Mari Yotsu-Yamashita
- Graduate School of Agricultural Science; Tohoku University; 468-1 Aramaki-Aza-Aoba, Aoba-ku Sendai 980-0845 Japan
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Cho Y, Tsuchiya S, Yoshioka R, Omura T, Konoki K, Oshima Y, Yotsu-Yamashita M. Column switching combined with hydrophilic interaction chromatography-tandem mass spectrometry for the analysis of saxitoxin analogues, and their biosynthetic intermediates in dinoflagellates. J Chromatogr A 2016; 1474:109-120. [DOI: 10.1016/j.chroma.2016.10.065] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Revised: 10/24/2016] [Accepted: 10/25/2016] [Indexed: 01/17/2023]
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Tsuchiya S, Cho Y, Konoki K, Nagasawa K, Oshima Y, Yotsu-Yamashita M. Biosynthetic route towards saxitoxin and shunt pathway. Sci Rep 2016; 6:20340. [PMID: 26842222 DOI: 10.1038/srep20340] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Accepted: 12/30/2015] [Indexed: 11/08/2022] Open
Abstract
Saxitoxin, the most potent voltage-gated sodium channel blocker, is one of the paralytic shellfish toxins (PSTs) produced by cyanobacteria and dinoflagellates. Recently, putative biosynthetic genes of PSTs were reported in these microorganisms. We previously synthesized genetically predicted biosynthetic intermediates, Int-A’ and Int-C’2, and also Cyclic-C’ which was not predicted based on gene, and identified them all in the toxin-producing cyanobacterium Anabaena circinalis (TA04) and the dinoflagellate Alexandrium tamarense (Axat-2). This study examined the incorporation of 15N-labeled intermediates into PSTs (C1 and C2) in A. circinalis (TA04). Conversions from Int-A’ to Int-C’2, from Int-C’2 to Cyclic-C’, and from Int-A’ and Int-C’2 to C1 and C2 were indicated using high resolution-LC/MS. However, Cyclic-C’ was not converted to C1 and C2 and was detected primarily in the extracellular medium. These results suggest that Int-A’ and Int-C’2 are genuine precursors of PSTs, but Int-C’2 converts partially to Cyclic-C’ which is a shunt product excreted to outside the cells. This paper provides the first direct demonstration of the biosynthetic route towards saxitoxin and a shunt pathway.
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Vale P. Can Mycosporine-Like Amino Acids Act as Multifunctional Compounds in Gymnodinium catenatum (Dinophyceae)? Photochem Photobiol 2016; 92:264-275. [PMID: 26756939 DOI: 10.1111/php.12561] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Accepted: 11/29/2015] [Indexed: 11/30/2022]
Abstract
MAAs originating from Gymnodinium catenatum were subjected to H2 O2 oxidation, light and heat. Shinorine and porphyra-334 were the more resistant to all treatments, mycosporine-glycine (MYGL) was the least resistant to oxidation and heat, whereas palythene and M-370 were the least resistant to light. MYGL and M-311 were similarly resistant to photodegradation and oxidation in the dark and low temperature, but M-311 was more resistant to oxidation under light or heat. The ratio M-370/M-365 changed from 29:1 to 6:1 ratio after 240 h of exposure to fluorescent light, indicating that M-365 could represent the M-370 cis-isomer. The role of MAAs as antioxidants and/or osmolytes was evaluated by studying effects of abrupt salinity reduction. Both increases or decreases in concentrations were observed and were dependent on the MAA initial concentration and its chemical structure. The relative increase in MAAs with a known antioxidant capacity (MYGL, palythene) followed an exponential decay trend related to initial concentration. The relative decrease in highly polar MAAs (shinorine, porphyra-334, M-332) with a suspected osmolyte role followed a rise to a maximum with the increase in initial concentration. Whether or not MAAs play a significant role in osmoregulation, their loss can occur upon hypoosmotic shock.
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Affiliation(s)
- Paulo Vale
- Departamento do Mar e Recursos Marinhos, Instituto Português do Mar e da Atmosfera, I.P. (IPMA), Lisbon, Portugal
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33
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Abstract
The present review discusses the isolation, structure determination, synthesis, biosynthesis and biological activities of secondary metabolites bearing a guanidine group.
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Affiliation(s)
| | - Stelamar Romminger
- Instituto de Química de São Carlos
- Universidade de São Paulo
- São Carlos
- Brazil
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34
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Kimura K, Okuda S, Nakayama K, Shikata T, Takahashi F, Yamaguchi H, Skamoto S, Yamaguchi M, Tomaru Y. RNA Sequencing Revealed Numerous Polyketide Synthase Genes in the Harmful Dinoflagellate Karenia mikimotoi. PLoS One 2015; 10:e0142731. [PMID: 26561394 PMCID: PMC4641656 DOI: 10.1371/journal.pone.0142731] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2015] [Accepted: 10/26/2015] [Indexed: 12/03/2022] Open
Abstract
The dinoflagellate Karenia mikimotoi forms blooms in the coastal waters of temperate regions and occasionally causes massive fish and invertebrate mortality. This study aimed to elucidate the toxic effect of K. mikimotoi on marine organisms by using the genomics approach; RNA-sequence libraries were constructed, and data were analyzed to identify toxin-related genes. Next-generation sequencing produced 153,406 transcript contigs from the axenic culture of K. mikimotoi. BLASTX analysis against all assembled contigs revealed that 208 contigs were polyketide synthase (PKS) sequences. Thus, K. mikimotoi was thought to have several genes encoding PKS metabolites and to likely produce toxin-like polyketide molecules. Of all the sequences, approximately 30 encoded eight PKS genes, which were remarkably similar to those of Karenia brevis. Our phylogenetic analyses showed that these genes belonged to a new group of PKS type-I genes. Phylogenetic and active domain analyses showed that the amino acid sequence of four among eight Karenia PKS genes was not similar to any of the reported PKS genes. These PKS genes might possibly be associated with the synthesis of polyketide toxins produced by Karenia species. Further, a homology search revealed 10 contigs that were similar to a toxin gene responsible for the synthesis of saxitoxin (sxtA) in the toxic dinoflagellate Alexandrium fundyense. These contigs encoded A1-A3 domains of sxtA genes. Thus, this study identified some transcripts in K. mikimotoi that might be associated with several putative toxin-related genes. The findings of this study might help understand the mechanism of toxicity of K. mikimotoi and other dinoflagellates.
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Affiliation(s)
- Kei Kimura
- National Research Institute of Fisheries and Environment of Inland Sea, Fisheries Research Agency, 2-17-5 Maruishi, Hatsukaichi, Hiroshima, Japan
- Research Fellow of the Japan Society for the Promotion of Science, Kojimachi Business Center Building, 5-3-1 Kojimachi, Chiyoda-ku, Tokyo, Japan
| | - Shujiro Okuda
- Niigata University Graduate School of Medical and Dental Sciences, 1–757 Asahimachi-dori, Chuo-ku, Niigata, Japan
| | - Kei Nakayama
- Center for Marine Environmental Studies (CMES), Ehime University, 2–5 Bunkyo-cho, Matsuyama, Ehime, Japan
| | - Tomoyuki Shikata
- National Research Institute of Fisheries and Environment of Inland Sea, Fisheries Research Agency, 2-17-5 Maruishi, Hatsukaichi, Hiroshima, Japan
| | - Fumio Takahashi
- Department of Biotechnology, College of Life Sciences, Rhitsumeikan University, 1-1-1 Noji-higashi, Kusatsu, Shiga, Japan
| | - Haruo Yamaguchi
- Laboratory of Aquatic Environmental Science, Faculty of Agriculture, Kochi University, 200, Monobe, Nankoku, Kochi, Japan
| | - Setsuko Skamoto
- National Research Institute of Fisheries and Environment of Inland Sea, Fisheries Research Agency, 2-17-5 Maruishi, Hatsukaichi, Hiroshima, Japan
| | - Mineo Yamaguchi
- National Research Institute of Fisheries and Environment of Inland Sea, Fisheries Research Agency, 2-17-5 Maruishi, Hatsukaichi, Hiroshima, Japan
| | - Yuji Tomaru
- National Research Institute of Fisheries and Environment of Inland Sea, Fisheries Research Agency, 2-17-5 Maruishi, Hatsukaichi, Hiroshima, Japan
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Wang DZ, Zhang SF, Zhang Y, Lin L. Paralytic shellfish toxin biosynthesis in cyanobacteria and dinoflagellates: A molecular overview. J Proteomics 2015; 135:132-140. [PMID: 26316331 DOI: 10.1016/j.jprot.2015.08.008] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Revised: 07/28/2015] [Accepted: 08/14/2015] [Indexed: 12/22/2022]
Abstract
UNLABELLED Paralytic shellfish toxins (PSTs) are a group of water soluble neurotoxic alkaloids produced by two different kingdoms of life, prokaryotic cyanobacteria and eukaryotic dinoflagellates. Owing to the wide distribution of these organisms, these toxic secondary metabolites account for paralytic shellfish poisonings around the world. On the other hand, their specific binding to voltage-gated sodium channels makes these toxins potentially useful in pharmacological and toxicological applications. Much effort has been devoted to the biosynthetic mechanism of PSTs, and gene clusters encoding 26 proteins involved in PST biosynthesis have been unveiled in several cyanobacterial species. Functional analysis of toxin genes indicates that PST biosynthesis in cyanobacteria is a complex process including biosynthesis, regulation, modification and export. However, less is known about the toxin biosynthesis in dinoflagellates owing to our poor understanding of the massive genome and unique chromosomal characteristics [1]. So far, few genes involved in PST biosynthesis have been identified from dinoflagellates. Moreover, the proteins involved in PST production are far from being totally explored. Thus, the origin and evolution of PST biosynthesis in these two kingdoms are still controversial. In this review, we summarize the recent progress on the characterization of genes and proteins involved in PST biosynthesis in cyanobacteria and dinoflagellates, and discuss the standing evolutionary hypotheses concerning the origin of toxin biosynthesis as well as future perspectives in PST biosynthesis. SCIENTIFIC QUESTION Paralytic shellfish toxins (PSTs) are a group of potent neurotoxins which specifically block voltage-gated sodium channels in excitable cells and result in paralytic shellfish poisonings (PSPs) around the world. Two different kingdoms of life, cyanobacteria and dinoflagellates are able to produce PSTs. However, in contrast with cyanobacteria, our understanding of PST biosynthesis in dinoflagellates is extremely limited owing to their unique features. The origin and evolution of PST biosynthesis in these two kingdoms are still controversial. TECHNICAL SIGNIFICANCE High-throughput omics technologies, such as genomics, transcriptomics and proteomics provide powerful tools for the study of PST biosynthesis in cyanobacteria and dinoflagellates, and have shown their powerful potential with regard to revealing genes and proteins involved in PST biosynthesis in two kingdoms. SCIENTIFIC SIGNIFICANCE This review summarizes the recent progress in PST biosynthesis in cyanobacteria and dinoflagellates with focusing on the novel insights from omics technologies, and discusses the evolutionary relationship of toxin biosynthesis genes between these two kingdoms.
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Affiliation(s)
- Da-Zhi Wang
- State Key Laboratory of Marine Environmental Science/College of the Environment and Ecology, Xiamen University, Xiamen 361005, China.
| | - Shu-Fei Zhang
- State Key Laboratory of Marine Environmental Science/College of the Environment and Ecology, Xiamen University, Xiamen 361005, China
| | - Yong Zhang
- State Key Laboratory of Marine Environmental Science/College of the Environment and Ecology, Xiamen University, Xiamen 361005, China
| | - Lin Lin
- State Key Laboratory of Marine Environmental Science/College of the Environment and Ecology, Xiamen University, Xiamen 361005, China
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Vale P. Effects of Light and Salinity Stresses in Production of Mycosporine-Like Amino Acids byGymnodinium catenatum(Dinophyceae). Photochem Photobiol 2015; 91:1112-22. [DOI: 10.1111/php.12488] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Accepted: 06/23/2015] [Indexed: 11/29/2022]
Affiliation(s)
- Paulo Vale
- Departamento do Mar e Recursos Marinhos; Instituto Português do Mar e da Atmosfera; I.P. (IPMA); Lisbon Portugal
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37
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Tsuchiya S, Cho Y, Konoki K, Nagasawa K, Oshima Y, Yotsu-Yamashita M. Synthesis of a Tricyclic Bisguanidine Compound Structurally Related to Saxitoxin and its Identification in Paralytic Shellfish Toxin-Producing Microorganisms. Chemistry 2015; 21:7835-40. [DOI: 10.1002/chem.201500064] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Indexed: 02/05/2023]
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Zhang X, Tian X, Ma L, Feng B, Liu Q, Yuan L, Fan C, Huang H, Huang H, Yang Q. Biodiversity of the Symbiotic Bacteria Associated with Toxic Marine Dinoflagellate Alexandrium tamarense. ACTA ACUST UNITED AC 2015. [DOI: 10.4236/jbm.2015.36004] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Zhang Y, Zhang SF, Lin L, Wang DZ. Comparative transcriptome analysis of a toxin-producing dinoflagellate Alexandrium catenella and its non-toxic mutant. Mar Drugs 2014; 12:5698-718. [PMID: 25421324 PMCID: PMC4245552 DOI: 10.3390/md12115698] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Revised: 10/11/2014] [Accepted: 10/29/2014] [Indexed: 01/11/2023] Open
Abstract
The dinoflagellates and cyanobacteria are two major kingdoms of life producing paralytic shellfish toxins (PSTs), a large group of neurotoxic alkaloids causing paralytic shellfish poisonings around the world. In contrast to the well elucidated PST biosynthetic genes in cyanobacteria, little is known about the dinoflagellates. This study compared transcriptome profiles of a toxin-producing dinoflagellate, Alexandrium catenella (ACHK-T), and its non-toxic mutant form (ACHK-NT) using RNA-seq. All clean reads were assembled de novo into a total of 113,674 unigenes, and 66,812 unigenes were annotated in the known databases. Out of them, 35 genes were found to express differentially between the two strains. The up-regulated genes in ACHK-NT were involved in photosynthesis, carbon fixation and amino acid metabolism processes, indicating that more carbon and energy were utilized for cell growth. Among the down-regulated genes, expression of a unigene assigned to the long isoform of sxtA, the initiator of toxin biosynthesis in cyanobacteria, was significantly depressed, suggesting that this long transcript of sxtA might be directly involved in toxin biosynthesis and its depression resulted in the loss of the ability to synthesize PSTs in ACHK-NT. In addition, 101 putative homologs of 12 cyanobacterial sxt genes were identified, and the sxtO and sxtZ genes were identified in dinoflagellates for the first time. The findings of this study should shed light on the biosynthesis of PSTs in the dinoflagellates.
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Affiliation(s)
- Yong Zhang
- State Key Laboratory of Marine Environmental Science, College of the Environment and Ecology, Xiamen University, Xiamen 361102, China.
| | - Shu-Fei Zhang
- State Key Laboratory of Marine Environmental Science, College of the Environment and Ecology, Xiamen University, Xiamen 361102, China.
| | - Lin Lin
- State Key Laboratory of Marine Environmental Science, College of the Environment and Ecology, Xiamen University, Xiamen 361102, China.
| | - Da-Zhi Wang
- State Key Laboratory of Marine Environmental Science, College of the Environment and Ecology, Xiamen University, Xiamen 361102, China.
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Wiese M, Murray SA, Alvin A, Neilan BA. Gene expression and molecular evolution of sxtA4 in a saxitoxin producing dinoflagellate Alexandrium catenella. Toxicon 2014; 92:102-12. [PMID: 25301480 DOI: 10.1016/j.toxicon.2014.09.015] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Accepted: 09/25/2014] [Indexed: 10/24/2022]
Abstract
Dinoflagellates of the genus Alexandrium produce the neurotoxin saxitoxin (STX), responsible for paralytic shellfish poisoning (PSP) and accumulates in marine invertebrates. The recent identification of STX biosynthesis genes allowed us to investigate the expression of sxtA4 at different growth stages in Alexandrium catenella Group IV. We found no significant differences in expression of sxtA4, despite significant differences in STX levels at different growth stages (P < 0.023). Three reference genes were tested for normalisation: actin, cytochrome b (cob), and the large subunit ribosomal RNA (LSU rDNA). cob was most stably expressed but the combination of two reference genes, actin and cob, resulted in the best stability factor. Most genomic sequences of sxtA4 from A. catenella were in a clade that included sequences from Alexandrium fundyense Group I, however, one paralogue was not related to the others, suggesting recombination or lateral transfer. A comparison of the sxtA4 cDNA sequences with genomic DNA sequences indicated the possibility of transcript editing and the preferential transcription of certain genomic DNA loci. The results show that, in dinoflagellates, post-transcriptional mechanisms play a major role in the regulation of saxitoxin biosynthesis.
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Affiliation(s)
- Maria Wiese
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia; Sydney Institute of Marine Science, Chowder Bay Rd, Mosman, NSW 2088, Australia.
| | - Shauna A Murray
- Sydney Institute of Marine Science, Chowder Bay Rd, Mosman, NSW 2088, Australia; Plant Functional Biology and Climate Change Cluster, University of Technology, Sydney, NSW 2007, Australia
| | - Alfonsus Alvin
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Brett A Neilan
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia; Sydney Institute of Marine Science, Chowder Bay Rd, Mosman, NSW 2088, Australia.
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Zepeda RJ, Candiracci M, Lobos N, Lux S, Miranda HF. Chronic toxicity study of neosaxitoxin in rats. Mar Drugs 2014; 12:5055-71. [PMID: 25257789 DOI: 10.3390/md12095055] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2014] [Revised: 06/06/2014] [Accepted: 07/07/2014] [Indexed: 01/31/2023] Open
Abstract
Neosaxitoxin (NeoSTX) is a specific reversible blocker of voltage gated sodium channels on excitable cells. In the last decade, it has been tested in a number of interesting clinical trials, however there is still little information available on mammalian toxicity. Rats were treated for 12 weeks with doses of 1, 3 or 6 μg/kg of subcutaneous NeoSTX. At weeks 12 and 17, animals were sacrificed and blood samples collected for hematological and biochemical analysis. Organs were harvested for weight determination and histopathological assessments. The lowest acute toxicity via the intraperitoneal (ip) route was (30.35 μg/kg) and there was no significant difference between intramuscular and subcutaneous routes (11.4 and 12.41 μg/kg). The NeoSTX adiministration did not produce lethality at week 12 and after five weeks of suspension. NeoSTX 6 μg/kg ip produced reductions (p < 0.05) in body weight and food intake, and increased blood level of total and direct bilirubin, GGT and SGOT at week 12; all of these were reversed in the recovery period. NeoSTX 1 and 3 μg/kg ip did not show significant changes with the control group. Histopathological presentations were normal in all groups. This study revealed that NeoSTX is safe in vivo, giving a reliable security margin for its use like a local anesthetic.
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Abstract
The paralytic shellfish toxin (PST)-producing dinoflagellate Gymnodinium catenatum grows in association with a complex marine bacterial community that is both essential for growth and can alter culture growth dynamics. Using a bacterial community replacement approach, we examined the intracellular PST content, production rate, and profile of G. catenatum cultures grown with bacterial communities of differing complexity and composition. Clonal offspring were established from surface-sterilized resting cysts (produced by sexual crosses of strain GCDE06 and strain GCLV01) and grown with: 1) complex bacterial communities derived from each of the two parent cultures; 2) simplified bacterial communities composed of the G. catenatum-associated bacteria Marinobacter sp. strain DG879 or Alcanivorax sp. strain DG881; 3) a complex bacterial community associated with an untreated, unsterilized sexual cross of the parents. Toxin content (STX-equivalent per cell) of clonal offspring (134–197 fmol STX cell−1) was similar to the parent cultures (169–206 fmol STX cell−1), however cultures grown with single bacterial types contained less toxin (134–146 fmol STX cell−1) than offspring or parent cultures grown with more complex mixed bacterial communities (152–176 fmol STX cell−1). Specific toxin production rate (fmol STX day−1) was strongly correlated with culture growth rate. Net toxin production rate (fmol STX cell−1 day−1) did not differ among treatments, however, mean net toxin production rate of offspring was 8-fold lower than the parent cultures, suggesting that completion of the sexual lifecycle in laboratory cultures leads to reduced toxin production. The PST profiles of offspring cultures were most similar to parent GCDE06 with the exception of cultures grown with Marinobacter sp. DG879 which produced higher proportions of dcGTX2+3 and GC1+2, and lower proportions of C1+2 and C3+4. Our data demonstrate that the bacterial community can alter intracellular STX production of dinoflagellates. In G. catenatum the mechanism appears likely to be due to bacterial effects on dinoflagellate physiology rather than bacterial biotransformation of PST toxins.
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Affiliation(s)
- Maria E. Albinsson
- National Centre for Marine Conservation and Resource Sustainability, Australian Maritime College, University of Tasmania, Launceston, Tasmania, Australia
- Commonwealth Scientific and Industrial Research Organisation, Marine and Atmospheric Research, Hobart, Tasmania, Australia
- * E-mail:
| | - Andrew P. Negri
- Australian Institute of Marine Science, Townsville, Queensland, Australia
| | - Susan I. Blackburn
- Commonwealth Scientific and Industrial Research Organisation, Marine and Atmospheric Research, Hobart, Tasmania, Australia
| | - Christopher J. S. Bolch
- National Centre for Marine Conservation and Resource Sustainability, Australian Maritime College, University of Tasmania, Launceston, Tasmania, Australia
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Wiese M, Murray SA, Alvin A, Neilan BA. WITHDRAWN: Gene expression and molecular evolution of sxtA4 in a saxitoxin producing dinoflagellate Alexandrium catenella. Toxicon 2014:S0041-0101(14)00193-7. [PMID: 25080311 DOI: 10.1016/j.toxicon.2014.07.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Revised: 07/08/2014] [Accepted: 07/15/2014] [Indexed: 10/25/2022]
Abstract
This article has been withdrawn at the request of the authors and editor. The Publisher apologizes for any inconvenience this may cause. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.
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Affiliation(s)
- Maria Wiese
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia; Sydney Institute of Marine Science, Chowder Bay Rd, Mosman, NSW 2088, Australia
| | - Shauna A Murray
- Sydney Institute of Marine Science, Chowder Bay Rd, Mosman, NSW 2088, Australia; Plant Functional Biology and Climate Change Cluster, University of Technology, Sydney, NSW 2007, Australia
| | - Alfonsus Alvin
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia; Sydney Institute of Marine Science, Chowder Bay Rd, Mosman, NSW 2088, Australia
| | - Brett A Neilan
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia; Sydney Institute of Marine Science, Chowder Bay Rd, Mosman, NSW 2088, Australia
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Tsuchiya S, Cho Y, Konoki K, Nagasawa K, Oshima Y, Yotsu-Yamashita M. Synthesis and identification of proposed biosynthetic intermediates of saxitoxin in the cyanobacterium Anabaena circinalis (TA04) and the dinoflagellate Alexandrium tamarense (Axat-2). Org Biomol Chem 2014; 12:3016-20. [DOI: 10.1039/c4ob00071d] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We synthesized the genetically predicted biosynthetic intermediates of saxitoxin (STX) (1),2,6and7, and identified2and6in microorganisms.
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Affiliation(s)
- Shigeki Tsuchiya
- Graduate School of Agricultural Science
- Tohoku University
- Sendai 981-8555, Japan
| | - Yuko Cho
- Graduate School of Agricultural Science
- Tohoku University
- Sendai 981-8555, Japan
| | - Keiichi Konoki
- Graduate School of Agricultural Science
- Tohoku University
- Sendai 981-8555, Japan
| | - Kazuo Nagasawa
- Faculty of Technology
- Tokyo University of Agriculture and Technology
- 2-24-16 Naka-cho
- Tokyo 184-8588, Japan
| | - Yasukatsu Oshima
- Graduate School of Life Sciences
- Tohoku University 1-1 Katahira
- Sendai 980-8577, Japan
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