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Wang H, Wu P, Xiong L, Kim HS, Kim JH, Ki JS. Nuclear genome of dinoflagellates: Size variation and insights into evolutionary mechanisms. Eur J Protistol 2024; 93:126061. [PMID: 38394997 DOI: 10.1016/j.ejop.2024.126061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Revised: 01/29/2024] [Accepted: 01/30/2024] [Indexed: 02/25/2024]
Abstract
Recent progress in high-throughput sequencing technologies has dramatically increased availability of genome data for prokaryotes and eukaryotes. Dinoflagellates have distinct chromosomes and a huge genome size, which make their genomic analysis complicated. Here, we reviewed the nuclear genomes of core dinoflagellates, focusing on the genome and cell size. Till now, the genome sizes of several dinoflagellates (more than 25) have been measured by certain methods (e.g., flow cytometry), showing a range of 3-250 pg of genomic DNA per cell. In contrast to their relatively small cell size, their genomes are huge (about 1-80 times the human haploid genome). In the present study, we collected the genome and cell size data of dinoflagellates and compared their relationships. We found that dinoflagellate genome size exhibits a positive correlation with cell size. On the other hand, we recognized that the genome size is not correlated with phylogenetic relatedness. These may be caused by genome duplication, increased gene copy number, repetitive non-coding DNA, transposon expansion, horizontal gene transfer, organelle-to-nucleus gene transfer, and/or mRNA reintegration into the genome. Ultimate verification of these factors as potential causative mechanisms would require sequencing of more dinoflagellate genomes in the future.
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Affiliation(s)
- Hui Wang
- Hunan Province Key Laboratory of Typical Environmental Pollution and Health Hazards, School of Public Health, Hengyang Medical School, University of South China, Hengyang 421001, China; Department of Life Science, Sangmyung University, Seoul 03016, Republic of Korea
| | - Peiling Wu
- Hunan Province Key Laboratory of Typical Environmental Pollution and Health Hazards, School of Public Health, Hengyang Medical School, University of South China, Hengyang 421001, China
| | - Lu Xiong
- Hunan Province Key Laboratory of Typical Environmental Pollution and Health Hazards, School of Public Health, Hengyang Medical School, University of South China, Hengyang 421001, China
| | - Han-Sol Kim
- Department of Life Science, Sangmyung University, Seoul 03016, Republic of Korea
| | - Jin Ho Kim
- Department of Earth and Marine Science, College of Ocean Sciences, Jeju National University, Jeju 63243, Republic of Korea
| | - Jang-Seu Ki
- Department of Life Science, Sangmyung University, Seoul 03016, Republic of Korea; Department of Biotechnology, Sangmyung University, Seoul 03016, Republic of Korea.
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2
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Dawydiak W, Gobler CJ. Transcription of biochemical defenses by the harmful brown tide pelagophyte, Aureococcus anophagefferens, in response to the protozoan grazer, Oxyrrhis marina. Front Microbiol 2023; 14:1295160. [PMID: 38163083 PMCID: PMC10756674 DOI: 10.3389/fmicb.2023.1295160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Accepted: 11/06/2023] [Indexed: 01/03/2024] Open
Abstract
Aureococcus anophagefferens is a small marine pelagophyte that forms recurrent harmful brown tides blooms with adverse ecological and economic impacts. During blooms, A. anophagefferens experiences lower zooplankton grazing mortality than other phytoplankton potentially due to the synthesis of anti-predator compounds including extracellular polysaccharides. This study characterized the transcriptomic response of A. anophagefferens when exposed to the protozooplankton, Oxyrrhis marina, and assessed whether this response involved chemical cues. Transcriptomes were generated from A. anophagefferens populations grown at high (1×106 cells mL-1) and low (5×105 cells mL-1) cell densities incubated directly with O. marina or receiving only filtrate from co-cultures of A. anophagefferens and O. marina to evaluate the role of chemical cues. There were a greater number of genes differentially expressed in response to grazing in the lower concentration of A. anophagefferens compared to the high concentration treatment and in response to direct grazing compared to filtrate. KEGG pathway analysis revealed that direct grazer exposure led to a significant increase in transcripts of genes encoding secondary metabolite production (p < 0.001). There was broad transcriptional evidence indicating the induction of biosynthetic pathways for polyketides and sterols in response to zooplankton grazers, compounds associated with damage to marine organisms. In addition, exposure to O. marina elicited changes in the abundance of transcripts associated with carbohydrate metabolism that could support the formation of an extracellular polysaccharide matrix including genes related to glycoprotein synthesis and carbohydrate transport. Collectively, these findings support the hypothesis that A. anophagefferens can induce biochemical pathways that reduce grazing mortality and support blooms.
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Affiliation(s)
| | - Christopher J. Gobler
- School of Marine and Atmospheric Sciences, Stony Brook University, Southampton, NY, United States
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3
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Tang J, Li W, Chiu TY, Martínez-Peña F, Luo Z, Chong CT, Wei Q, Gazaniga N, West TJ, See YY, Lairson LL, Parker CG, Baran PS. Synthesis of portimines reveals the basis of their anti-cancer activity. Nature 2023; 622:507-513. [PMID: 37730997 PMCID: PMC10699793 DOI: 10.1038/s41586-023-06535-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Accepted: 08/11/2023] [Indexed: 09/22/2023]
Abstract
Marine-derived cyclic imine toxins, portimine A and portimine B, have attracted attention because of their chemical structure and notable anti-cancer therapeutic potential1-4. However, access to large quantities of these toxins is currently not feasible, and the molecular mechanism underlying their potent activity remains unknown until now. To address this, a scalable and concise synthesis of portimines is presented, which benefits from the logic used in the two-phase terpenoid synthesis5,6 along with other tactics such as exploiting ring-chain tautomerization and skeletal reorganization to minimize protecting group chemistry through self-protection. Notably, this total synthesis enabled a structural reassignment of portimine B and an in-depth functional evaluation of portimine A, revealing that it induces apoptosis selectively in human cancer cell lines with high potency and is efficacious in vivo in tumour-clearance models. Finally, practical access to the portimines and their analogues simplified the development of photoaffinity analogues, which were used in chemical proteomic experiments to identify a primary target of portimine A as the 60S ribosomal export protein NMD3.
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Affiliation(s)
- Junchen Tang
- Department of Chemistry, Scripps Research, La Jolla, CA, USA
| | - Weichao Li
- Department of Chemistry, Scripps Research, La Jolla, CA, USA
| | - Tzu-Yuan Chiu
- Department of Chemistry, Scripps Research, La Jolla, CA, USA
| | | | - Zengwei Luo
- Department of Chemistry, Scripps Research, La Jolla, CA, USA
| | | | - Qijia Wei
- Department of Chemistry, Scripps Research, La Jolla, CA, USA
| | | | - Thomas J West
- Department of Chemistry, Scripps Research, La Jolla, CA, USA
| | - Yi Yang See
- Department of Chemistry, Scripps Research, La Jolla, CA, USA
| | - Luke L Lairson
- Department of Chemistry, Scripps Research, La Jolla, CA, USA.
| | | | - Phil S Baran
- Department of Chemistry, Scripps Research, La Jolla, CA, USA.
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4
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Bashir F, Bashir A, Bouaïcha N, Chen L, Codd GA, Neilan B, Xu WL, Ziko L, Rajput VD, Minkina T, Arruda RS, Ganai BA. Cyanotoxins, biosynthetic gene clusters, and factors modulating cyanotoxin biosynthesis. World J Microbiol Biotechnol 2023; 39:241. [PMID: 37394567 DOI: 10.1007/s11274-023-03652-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Accepted: 05/17/2023] [Indexed: 07/04/2023]
Abstract
Cyanobacterial harmful algal blooms (CHABs) are a global environmental concern that encompasses public health issues, water availability, and water quality owing to the production of various secondary metabolites (SMs), including cyanotoxins in freshwater, brackish water, and marine ecosystems. The frequency, extent, magnitude, and duration of CHABs are increasing globally. Cyanobacterial species traits and changing environmental conditions, including anthropogenic pressure, eutrophication, and global climate change, together allow cyanobacteria to thrive. The cyanotoxins include a diverse range of low molecular weight compounds with varying biochemical properties and modes of action. With the application of modern molecular biology techniques, many important aspects of cyanobacteria are being elucidated, including aspects of their diversity, gene-environment interactions, and genes that express cyanotoxins. The toxicological, environmental, and economic impacts of CHABs strongly advocate the need for continuing, extensive efforts to monitor cyanobacterial growth and to understand the mechanisms regulating species composition and cyanotoxin biosynthesis. In this review, we critically examined the genomic organization of some cyanobacterial species that lead to the production of cyanotoxins and their characteristic properties discovered to date.
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Affiliation(s)
- Fahim Bashir
- Department of Environmental Science, University of Kashmir, Srinagar, Jammu and Kashmir, 190006, India
| | - Arif Bashir
- Department of Clinical Biochemistry and Biotechnology, Government College for Women, Nawa-Kadal, Srinagar, Jammu & Kashmir, India
| | - Noureddine Bouaïcha
- Laboratory Ecology, Systematic, and Evolution, UMR 8079 Univ. Paris-Sud, CNRS, AgroParisTech, University Paris-Saclay, 91190, Gif-sur-Yvette, France.
| | - Liang Chen
- Institute for Ecological Research and Pollution Control of Plateau Lakes, School of Ecology and Environmental Science (SEES), Yunnan University (YNU), 650500, Kunming, China.
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology (IHB), Chinese Academy of Sciences (CAS), Wuhan, 430072, China.
- State Key Laboratory of Eco-Hydraulics in Northwest Arid Region, Faculty of Water Resources and Hydroelectric Engineering, Xi'an University of Technology, Xi'an, 710048, China.
| | - Geoffrey A Codd
- Biological and Environmental Sciences, University of Stirling, Stirling, FK9 4LA, Scotland, UK
- School of Life Sciences, University of Dundee, Dundee, DD1 5EH, Scotland, UK
| | - Brett Neilan
- School of Environmental and Life Sciences, University of Newcastle, Callaghan, NSW, Australia
| | - Wen-Li Xu
- Donghu Experimental Station of Lake Ecosystems, State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology (IHB), Chinese Academy of Sciences (CAS), Wuhan, 430072, China
| | - Laila Ziko
- School of Life and Medical Sciences, University of Hertfordshire Hosted By Global Academic Foundation, Cairo, Egypt
- Biology Department, School of Sciences and Engineering, The American University in Cairo, New Cairo, 11835, Egypt
| | - Vishnu D Rajput
- Academy of Biology and Biotechnology, Southern Federal University, Rostov-On-Don, Russia
| | - Tatiana Minkina
- Academy of Biology and Biotechnology, Southern Federal University, Rostov-On-Don, Russia
| | - Renan Silva Arruda
- Laboratory of Ecology and Physiology of Phytoplankton, Department of Plant Biology, University of Rio de Janeiro State, Rio de Janeiro, Brazil
| | - Bashir Ahmad Ganai
- Center of Research for Development (CORD), University of Kashmir, Srinagar, Jammu and Kashmir, 190006, India.
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5
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Durán-Riveroll LM, Weber J, Krock B. First Identification of Amphidinols from Mexican Strains and New Analogs. Toxins (Basel) 2023; 15:163. [PMID: 36828476 PMCID: PMC9961859 DOI: 10.3390/toxins15020163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2022] [Revised: 01/25/2023] [Accepted: 02/10/2023] [Indexed: 02/18/2023] Open
Abstract
The genus Amphidinium has been the subject of recent attention due to the production of polyketide metabolites. Some of these compounds have shown significant bioactivities and could be related to species interactions in the natural benthic microenvironment. Among these compounds, amphidinols (AMs) are suspected to be related to fish kills and probably implicated in ciguatera symptoms associated with the occurrence of benthic harmful algal blooms (bHABs). Here, we present the first report of a variety of AMs produced by cultured strains from several species from the Mexican Pacific, the Gulf of California, and the Gulf of Mexico. Through ultra-high performance liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS), ten previously known AMs (AM02, -04, -05, -06, -07, -09, -11, -14, -15, and -17), four recently reported AMs (N7, N8/N9, N12, and N13), and three new variants (U1, U2, and U3) were identified. Of the twelve analyzed Amphidinium cultures, five were not AM producers, and the cell quotas of the remaining seven strains ranged from close to nondetectable to a maximum of 1694 fg cell-1, with many intermediate levels in between. The cultures from the Mexican North Pacific coast produced AMs in a higher quantity and variety than those from worldwide locations. This is the first study of AMs from Mexican Amphidinium strains, and our results confirm the relevance of continuing the investigation of the genus bioactive metabolites.
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Affiliation(s)
- Lorena M. Durán-Riveroll
- CONACyT-Departamento de Biotecnología Marina, Centro de Investigación Científica y de Educación Superior de Ensenada, Ensenada 22860, Baja California, Mexico
- Alfred Wegener Institut-Helmholtz Zentrum für Polar und Meeresforschung, 27570 Bremerhaven, Germany
| | - Jannik Weber
- Alfred Wegener Institut-Helmholtz Zentrum für Polar und Meeresforschung, 27570 Bremerhaven, Germany
- Hochschule RheinMain, 65428 Rüsselsheim, Germany
| | - Bernd Krock
- Alfred Wegener Institut-Helmholtz Zentrum für Polar und Meeresforschung, 27570 Bremerhaven, Germany
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6
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Lin S, Hu Z, Song X, Gobler CJ, Tang YZ. Vitamin B 12-auxotrophy in dinoflagellates caused by incomplete or absent cobalamin-independent methionine synthase genes ( metE). FUNDAMENTAL RESEARCH 2022; 2:727-737. [PMID: 38933134 PMCID: PMC11197592 DOI: 10.1016/j.fmre.2021.12.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Revised: 12/17/2021] [Accepted: 12/28/2021] [Indexed: 10/19/2022] Open
Abstract
Dinoflagellates are responsible for most marine harmful algal blooms (HABs) and play vital roles in many ocean processes. More than 90% of dinoflagellates are vitamin B12 auxotrophs and that B12 availability can control dinoflagellate HABs, yet the genetic basis of B12 auxotrophy in dinoflagellates in the framework of the ecology of dinoflagellates and particularly HABs, which was the objective of this work. Here, we investigated the presence, phylogeny, and transcription of two methionine synthase genes (B12-dependent metH and B12-independent metE) via searching and assembling transcripts and genes from transcriptomic and genomic databases, cloning 38 cDNA isoforms of the two genes from 14 strains of dinoflagellates, measuring the expression at different scenarios of B12, and comprehensive phylogenetic analyses of more than 100 organisms. We found that 1) metH was present in all 58 dinoflagellates accessible and metE was present in 40 of 58 species, 2) all metE genes lacked N-terminal domains, 3) metE of dinoflagellates were phylogenetically distinct from other known metE genes, and 4) expression of metH in dinoflagellates was responsive to exogenous B12 levels while expression of metE was not responding as that of genuine metE genes. We conclude that most, hypothetically all, dinoflagellates have either non-functional metE genes lacking N-terminal domain for most species, or do not possess metE for other species, which provides the genetic basis for the widespread nature of B12 auxotrophy in dinoflagellates. The work elucidated a fundamental aspect of the nutritional ecology of dinoflagellates.
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Affiliation(s)
- Siheng Lin
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
- Current address: Department of Biological Sciences and Biotechnology, Minnan Normal University, Zhangzhou 363000, China
| | - Zhangxi Hu
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
- Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China
- Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China
| | - Xiaoying Song
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | | | - Ying Zhong Tang
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
- Laboratory for Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China
- Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China
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7
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Dembitsky VM. Natural Polyether Ionophores and Their Pharmacological Profile. Mar Drugs 2022; 20:292. [PMID: 35621943 PMCID: PMC9144361 DOI: 10.3390/md20050292] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 04/18/2022] [Accepted: 04/20/2022] [Indexed: 02/04/2023] Open
Abstract
This review is devoted to the study of the biological activity of polyether ionophores produced by bacteria, unicellular marine algae, red seaweeds, marine sponges, and coelenterates. Biological activities have been studied experimentally in various laboratories, as well as data obtained using QSAR (Quantitative Structure-Activity Relationships) algorithms. According to the data obtained, it was shown that polyether toxins exhibit strong antibacterial, antimicrobial, antifungal, antitumor, and other activities. Along with this, it was found that natural polyether ionophores exhibit such properties as antiparasitic, antiprotozoal, cytostatic, anti-mycoplasmal, and antieczema activities. In addition, polyethers have been found to be potential regulators of lipid metabolism or inhibitors of DNA synthesis. Further study of the mechanisms of action and the search for new polyether ionophores and their derivatives may provide more effective therapeutic natural polyether ionophores for the treatment of cancer and other diseases. For some polyether ionophores, 3D graphs are presented, which demonstrate the predicted and calculated activities. The data presented in this review will be of interest to pharmacologists, chemists, practical medicine, and the pharmaceutical industry.
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Affiliation(s)
- Valery M Dembitsky
- Centre for Applied Research, Innovation and Entrepreneurship, Lethbridge College, 3000 College Drive South, Lethbridge, AB T1K 1L6, Canada
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Alzheimer’s Disease and Toxins Produced by Marine Dinoflagellates: An Issue to Explore. Mar Drugs 2022; 20:md20040253. [PMID: 35447926 PMCID: PMC9029327 DOI: 10.3390/md20040253] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 03/21/2022] [Accepted: 03/30/2022] [Indexed: 12/10/2022] Open
Abstract
This paper examined the toxins naturally produced by marine dinoflagellates and their effects on increases in β-amyloid plaques along with tau protein hyperphosphorylation, both major drivers of Alzheimer’s disease (AD). This approach is in line with the demand for certain natural compounds, namely those produced by marine invertebrates that have the potential to be used in the treatment of AD. Current advances in AD treatment are discussed as well as the main factors that potentially affect the puzzling global AD pattern. This study focused on yessotoxins (YTXs), gymnodimine (GYM), spirolides (SPXs), and gambierol, all toxins that have been shown to reduce β-amyloid plaques and tau hyperphosphorylation, thus preventing the neuronal or synaptic dysfunction that ultimately causes the cell death associated with AD (or other neurodegenerative diseases). Another group of toxins described, okadaic acid (OA) and its derivatives, inhibit protein phosphatase activity, which facilitates the presence of phosphorylated tau proteins. A few studies have used OA to trigger AD in zebrafish, providing an opportunity to test in vivo the effectiveness of new drugs in treating or attenuating AD. Constraints on the production of marine toxins for use in these tests have been considered. Different lines of research are anticipated regarding the action of the two groups of toxins.
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Wang H, Kim H, Park H, Ki JS. Temperature influences the content and biosynthesis gene expression of saxitoxins (STXs) in the toxigenic dinoflagellate Alexandrium pacificum. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 802:149801. [PMID: 34454155 DOI: 10.1016/j.scitotenv.2021.149801] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 08/16/2021] [Accepted: 08/17/2021] [Indexed: 06/13/2023]
Abstract
Temperature may affect the production of saxitoxin (STX) and its derivatives (STXs); however, this is still controversial. Further, STX-biosynthesis gene regulation and the relation of its toxicity with temperature are not clearly understood. In the present study, we evaluated the effects of different temperatures (12 °C, 16 °C, and 20 °C) on the growth, toxin profiles, and expression of two core STX-biosynthesis genes, sxtA and sxtG, in the toxic dinoflagellate Alexandrium pacificum Alex05, isolated from Korean coasts. We found that temperature significantly affected cell growth, with maximum growth recorded at 16 °C, followed by 20 °C and 12 °C. HPLC analysis revealed mostly 12 of STXs from the tested cultures. Interestingly, the contents of STXs increased in the cells cultured at 16 °C and exposed to cold stress, compared to the 20 °C culture and heat stress; however, toxin components were much more diverse under heat stress. These toxin profiles generally matched with the sxtA and sxtG expression levels. Incubation at lower temperatures (12 °C and 16 °C) and exposure to cold stress increased sxtA and sxtG expressions in the cells, whereas heat stress showed little change or downregulated the transcription of both genes. Principal component analysis (PCA) showed low correlation between STXs eq and expressional levels of sxtA and sxtG in heat-stressed cells. These results suggest that temperature might be a crucial factor affecting the level and biosynthesis of STXs in marine toxic dinoflagellates.
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Affiliation(s)
- Hui Wang
- Department of Biotechnology, Sangmyung University, Seoul 03016, South Korea; Hunan Key Laboratory of Typical Environmental Pollution and Health Hazards, School of Public Health, Hengyang Medical School, University of South China, Hengyang 421001, China
| | - Hansol Kim
- Department of Biotechnology, Sangmyung University, Seoul 03016, South Korea
| | - Hyunjun Park
- Department of Biotechnology, Sangmyung University, Seoul 03016, South Korea
| | - Jang-Seu Ki
- Department of Biotechnology, Sangmyung University, Seoul 03016, South Korea.
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Long M, Krock B, Castrec J, Tillmann U. Unknown Extracellular and Bioactive Metabolites of the Genus Alexandrium: A Review of Overlooked Toxins. Toxins (Basel) 2021; 13:905. [PMID: 34941742 PMCID: PMC8703713 DOI: 10.3390/toxins13120905] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 12/08/2021] [Accepted: 12/14/2021] [Indexed: 12/04/2022] Open
Abstract
Various species of Alexandrium can produce a number of bioactive compounds, e.g., paralytic shellfish toxins (PSTs), spirolides, gymnodimines, goniodomins, and also uncharacterised bioactive extracellular compounds (BECs). The latter metabolites are released into the environment and affect a large range of organisms (from protists to fishes and mammalian cell lines). These compounds mediate allelochemical interactions, have anti-grazing and anti-parasitic activities, and have a potentially strong structuring role for the dynamic of Alexandrium blooms. In many studies evaluating the effects of Alexandrium on marine organisms, only the classical toxins were reported and the involvement of BECs was not considered. A lack of information on the presence/absence of BECs in experimental strains is likely the cause of contrasting results in the literature that render impossible a distinction between PSTs and BECs effects. We review the knowledge on Alexandrium BEC, (i.e., producing species, target cells, physiological effects, detection methods and molecular candidates). Overall, we highlight the need to identify the nature of Alexandrium BECs and urge further research on the chemical interactions according to their ecological importance in the planktonic chemical warfare and due to their potential collateral damage to a wide range of organisms.
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Affiliation(s)
- Marc Long
- IFREMER, Centre de Brest, DYNECO Pelagos, 29280 Plouzané, France;
| | - Bernd Krock
- Alfred Wegener Institute for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany;
| | - Justine Castrec
- University Brest, CNRS, IRD, Ifremer, LEMAR, 29280 Plouzané, France;
- Station de Recherches Sous-Marines et Océanographiques (STARESO), Punta Revellata, BP33, 20260 Calvi, France
| | - Urban Tillmann
- Alfred Wegener Institute for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany;
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11
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Sprecher BN, Zhang H, Park G, Lin S. Isolation from a fish kill and transcriptomic characterization of Gyrodinium jinhaense off Long Island Sound. HARMFUL ALGAE 2021; 110:102136. [PMID: 34887013 DOI: 10.1016/j.hal.2021.102136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Revised: 11/01/2021] [Accepted: 11/08/2021] [Indexed: 06/13/2023]
Abstract
First found in Korean coastal water, the dinoflagellate Gyrodinium jinhaense is a recently established species with unclear global distribution and unexplored genomic characteristics. From a laboratory fish mortality event off Long Island Sound, USA, we isolated a dinoflagellate, and by microscopic and molecular (18S rRNA gene; >99% identical) analyses found that it resembles G. jinhaense, hence named G. jinhaense strain AP17. Towards developing a genetic database for this dinoflagellate, a transcriptome of this species was sequenced using RNA-seq, producing 6 Gbp of data that was assembled into over 70,000 unigenes. The assembled transcriptome GC content was approximately 56% and the total Benchmarking Universal Single-Copy Orthologs for Eukaryota and Alveolata databases were approximately 50% and 57%, respectfully. Genes involved in grazing, energy generation, genome architecture, and protein synthesis, processing, and degradation were highly represented in the transcriptome. Moreover, fragments of polyketide synthase and saxitoxin genes were found but saxitoxins were not detected in high performance liquid chromatography measurements. With the first reported transcriptome for the Gyrodinium genus, this study will serve as a baseline for future Gyrodinium genomics and toxicological studies.
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Affiliation(s)
- Brittany N Sprecher
- University of Connecticut Avery Point, 1084 Shennecossett Rd, Groton, CT 06340, United States; Current Address - University of Konstanz, Universitätsstraße 10, 78462 Konstanz, Germany.
| | - Huan Zhang
- University of Connecticut Avery Point, 1084 Shennecossett Rd, Groton, CT 06340, United States
| | - Gihong Park
- University of Connecticut Avery Point, 1084 Shennecossett Rd, Groton, CT 06340, United States
| | - Senjie Lin
- University of Connecticut Avery Point, 1084 Shennecossett Rd, Groton, CT 06340, United States.
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12
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Barone ME, Murphy E, Parkes R, Fleming GTA, Campanile F, Thomas OP, Touzet N. Antibacterial Activity and Amphidinol Profiling of the Marine Dinoflagellate Amphidinium carterae (Subclade III). Int J Mol Sci 2021; 22:ijms222212196. [PMID: 34830076 PMCID: PMC8618426 DOI: 10.3390/ijms222212196] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 11/01/2021] [Accepted: 11/05/2021] [Indexed: 12/24/2022] Open
Abstract
Microalgae have received growing interest for their capacity to produce bioactive metabolites. This study aimed at characterising the antimicrobial potential of the marine dinoflagellate Amphidinium carterae strain LACW11, isolated from the west of Ireland. Amphidinolides have been identified as cytotoxic polyoxygenated polyketides produced by several Amphidinium species. Phylogenetic inference assigned our strain to Amphidinium carterae subclade III, along with isolates interspersed in different geographic regions. A two-stage extraction and fractionation process of the biomass was carried out. Extracts obtained after stage-1 were tested for bioactivity against bacterial ATCC strains of Staphylococcus aureus, Enterococcus faecalis, Escherichia coli and Pseudomonas aeruginosa. The stage-2 solid phase extraction provided 16 fractions, which were tested against S. aureus and E. faecalis. Fractions I, J and K yielded minimum inhibitory concentrations between 16 μg/mL and 256 μg/mL for both Gram-positive. A targeted metabolomic approach using UHPLC-HRMS/MS analysis applied on fractions G to J evidenced the presence of amphidinol type compounds AM-A, AM-B, AM-22 and a new derivative dehydroAM-A, with characteristic masses of m/z 1361, 1463, 1667 and 1343, respectively. Combining the results of the biological assays with the targeted metabolomic approach, we could conclude that AM-A and the new derivative dehydroAM-A are responsible for the detected antimicrobial bioactivity.
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Affiliation(s)
- Maria Elena Barone
- Centre for Environmental Research, Sustainability and Innovation, Department of Environmental Science, School of Science, Institute of Technology Sligo, Ash Ln, Ballytivnan, F91 YW50 Sligo, Ireland; (M.E.B.); (R.P.)
| | - Elliot Murphy
- Marine Biodiversity, School of Chemistry, Ryan Institute, National University of Ireland Galway (NUI Galway), University Road, H91 TK33 Galway, Ireland;
| | - Rachel Parkes
- Centre for Environmental Research, Sustainability and Innovation, Department of Environmental Science, School of Science, Institute of Technology Sligo, Ash Ln, Ballytivnan, F91 YW50 Sligo, Ireland; (M.E.B.); (R.P.)
| | - Gerard T. A. Fleming
- Discipline of Microbiology, School of Natural Science, National University of Ireland Galway (NUI Galway), University Road, H91 TK33 Galway, Ireland;
| | - Floriana Campanile
- Medical Molecular Microbiology and Antibiotic Resistance Laboratory (MMARLab), Department of Biomedical and Biotechnological Sciences, University of Catania, Via Santa Sofia n. 97, 95123 Catania, Italy;
| | - Olivier P. Thomas
- Marine Biodiversity, School of Chemistry, Ryan Institute, National University of Ireland Galway (NUI Galway), University Road, H91 TK33 Galway, Ireland;
- Correspondence: (O.P.T.); (N.T.)
| | - Nicolas Touzet
- Centre for Environmental Research, Sustainability and Innovation, Department of Environmental Science, School of Science, Institute of Technology Sligo, Ash Ln, Ballytivnan, F91 YW50 Sligo, Ireland; (M.E.B.); (R.P.)
- Correspondence: (O.P.T.); (N.T.)
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13
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Unlocking the Health Potential of Microalgae as Sustainable Sources of Bioactive Compounds. Int J Mol Sci 2021; 22:ijms22094383. [PMID: 33922258 PMCID: PMC8122763 DOI: 10.3390/ijms22094383] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 04/14/2021] [Accepted: 04/18/2021] [Indexed: 12/15/2022] Open
Abstract
Microalgae are known to produce a plethora of compounds derived from the primary and secondary metabolism. Different studies have shown that these compounds may have allelopathic, antimicrobial, and antipredator activities. In addition, in vitro and in vivo screenings have shown that several compounds have interesting bioactivities (such as antioxidant, anti-inflammatory, anticancer, and antimicrobial) for the possible prevention and treatment of human pathologies. Additionally, the enzymatic pathways responsible for the synthesis of these compounds, and the targets and mechanisms of their action have also been investigated for a few species. However, further research is necessary for their full exploitation and possible pharmaceutical and other industrial applications. Here, we review the current knowledge on the chemical characteristics, biological activities, mechanism of action, and the enzymes involved in the synthesis of microalgal metabolites with potential benefits for human health.
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14
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Durán-Vinet B, Araya-Castro K, Chao TC, Wood SA, Gallardo V, Godoy K, Abanto M. Potential applications of CRISPR/Cas for next-generation biomonitoring of harmful algae blooms: A review. HARMFUL ALGAE 2021; 103:102027. [PMID: 33980455 DOI: 10.1016/j.hal.2021.102027] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 03/01/2021] [Accepted: 03/21/2021] [Indexed: 06/12/2023]
Abstract
Research on harmful algal and cyanobacterial blooms (HABs and CHABs) has risen dramatically due to their increasing global distribution, frequency, and intensity. These blooms jeopardize public health, ecosystem function, sustainability and can have negative economic impacts. Numerous monitoring programs have been established using light microscopy, liquid chromatography coupled to mass spectrometry (LC-MS), ELISA, and spectrophotometry to monitor HABs/CHABs outbreaks. Recently, DNA/RNA-based molecular methods have been integrated into these programs to replace or complement traditional methods through analyzing environmental DNA and RNA (eDNA/eRNA) with techniques such as quantitative polymerase chain reaction (qPCR), fluorescent in situ hybridization (FISH), sandwich hybridization assay (SHA), isothermal amplification methods, and microarrays. These have enabled the detection of rare or cryptic species, enhanced sample throughput, and reduced costs and the need for visual taxonomic expertise. However, these methods have limitations, such as the need for high capital investment in equipment or detection uncertainties, including determining whether organisms are viable. In this review, we discuss the potential of newly developed molecular diagnosis technology based on Clustered Regularly Interspaced Short Palindromic Repeats/Cas proteins (CRISPR/Cas), which utilizes the prokaryotic adaptative immune systems of bacteria and archaea. Cas12 and Cas13-based platforms can detect both DNA and RNA with attomolar sensitivity within an hour. CRISPR/Cas diagnostic is a rapid, inexpensive, specific, and ultrasensitive technology that, with some further development, will provide many new platforms that can be used for HABs/CHABs biomonitoring and research.
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Affiliation(s)
- B Durán-Vinet
- Scientific and Technological Bioresource Nucleus (BIOREN-UFRO), Genomics and Bioinformatics Unit, Universidad de La Frontera, Av. Francisco Salazar, 1145 Temuco, Chile; Bachelor of Biotechnology (Honours) Program, Faculty of Agricultural and Forestry Sciences, Universidad de La Frontera, Av. Francisco Salazar, 1145 Temuco, Chile.
| | - K Araya-Castro
- Doctoral Program in Science of Natural Resources, Universidad de La Frontera, Av. Francisco Salazar, 1145 Temuco, Chile
| | - T C Chao
- Institute of Environmental Change & Society, Department of Biology, University of Regina, Wascana Parkway, 3737 Regina, Canada
| | - S A Wood
- Coastal and Freshwater Group, Cawthron Institute, 98 Halifax Street East, Nelson 7010, New Zealand
| | - V Gallardo
- Scientific and Technological Bioresource Nucleus (BIOREN-UFRO), Genomics and Bioinformatics Unit, Universidad de La Frontera, Av. Francisco Salazar, 1145 Temuco, Chile; Bachelor of Biotechnology (Honours) Program, Faculty of Agricultural and Forestry Sciences, Universidad de La Frontera, Av. Francisco Salazar, 1145 Temuco, Chile
| | - K Godoy
- Scientific and Technological Bioresource Nucleus (BIOREN-UFRO), Microscopy and Flow Cytometry Unit, Universidad de La Frontera, Av. Francisco Salazar, 1145 Temuco, Chile
| | - M Abanto
- Scientific and Technological Bioresource Nucleus (BIOREN-UFRO), Genomics and Bioinformatics Unit, Universidad de La Frontera, Av. Francisco Salazar, 1145 Temuco, Chile
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15
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Geffroy S, Lechat MM, Le Gac M, Rovillon GA, Marie D, Bigeard E, Malo F, Amzil Z, Guillou L, Caruana AMN. From the sxtA4 Gene to Saxitoxin Production: What Controls the Variability Among Alexandrium minutum and Alexandrium pacificum Strains? Front Microbiol 2021; 12:613199. [PMID: 33717003 PMCID: PMC7944994 DOI: 10.3389/fmicb.2021.613199] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Accepted: 02/03/2021] [Indexed: 12/22/2022] Open
Abstract
Paralytic shellfish poisoning (PSP) is a human foodborne syndrome caused by the consumption of shellfish that accumulate paralytic shellfish toxins (PSTs, saxitoxin group). In PST-producing dinoflagellates such as Alexandrium spp., toxin synthesis is encoded in the nuclear genome via a gene cluster (sxt). Toxin production is supposedly associated with the presence of a 4th domain in the sxtA gene (sxtA4), one of the core genes of the PST gene cluster. It is postulated that gene expression in dinoflagellates is partially constitutive, with both transcriptional and post-transcriptional processes potentially co-occurring. Therefore, gene structure and expression mode are two important features to explore in order to fully understand toxin production processes in dinoflagellates. In this study, we determined the intracellular toxin contents of twenty European Alexandrium minutum and Alexandrium pacificum strains that we compared with their genome size and sxtA4 gene copy numbers. We observed a significant correlation between the sxtA4 gene copy number and toxin content, as well as a moderate positive correlation between the sxtA4 gene copy number and genome size. The 18 toxic strains had several sxtA4 gene copies (9-187), whereas only one copy was found in the two observed non-toxin producing strains. Exploration of allelic frequencies and expression of sxtA4 mRNA in 11 A. minutum strains showed both a differential expression and specific allelic forms in the non-toxic strains compared with the toxic ones. Also, the toxic strains exhibited a polymorphic sxtA4 mRNA sequence between strains and between gene copies within strains. Finally, our study supported the hypothesis of a genetic determinism of toxin synthesis (i.e., the existence of several genetic isoforms of the sxtA4 gene and their copy numbers), and was also consistent with the hypothesis that constitutive gene expression and moderation by transcriptional and post-transcriptional regulation mechanisms are the cause of the observed variability in the production of toxins by A. minutum.
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Affiliation(s)
| | | | | | | | - Dominique Marie
- Sorbonne Université, CNRS, UMR 7144 Adaptation et Diversité en Milieu Marin, Station Biologique de Roscoff, Roscoff, France
| | - Estelle Bigeard
- Sorbonne Université, CNRS, UMR 7144 Adaptation et Diversité en Milieu Marin, Station Biologique de Roscoff, Roscoff, France
| | | | | | - Laure Guillou
- Sorbonne Université, CNRS, UMR 7144 Adaptation et Diversité en Milieu Marin, Station Biologique de Roscoff, Roscoff, France
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16
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A Polyol-Polyol Super-Carbon-Chain Compound Containing Thirty-Six Carbon Stereocenters from the Dinoflagellate Amphidinium gibbosum: Absolute Configuration and Multi-Segment Modification. Mar Drugs 2020; 18:md18120590. [PMID: 33255887 PMCID: PMC7759953 DOI: 10.3390/md18120590] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 11/21/2020] [Accepted: 11/22/2020] [Indexed: 12/24/2022] Open
Abstract
A super-carbon-chain compound, named gibbosol C, featuring a polyoxygenated C70-linear-carbon-chain backbone encompassing two acyclic polyol chains, was obtained from the South China Sea dinoflagellate Amphidinium gibbosum. Its planar structure was elucidated by extensive NMR investigations, whereas its absolute configurations, featuring the presence of 36 carbon stereocenters and 30 hydroxy groups, were successfully established by comparison of NMR data of the ozonolyzed products with those of gibbosol A, combined with J-based configuration analysis, Kishi’s universal NMR database, and the modified Mosher’s MTPA ester method. Multi-segment modification was revealed as the smart biosynthetic strategy for the dinoflagellate to create remarkable super-carbon-chain compounds with structural diversity.
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17
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Beedessee G, Kubota T, Arimoto A, Nishitsuji K, Waller RF, Hisata K, Yamasaki S, Satoh N, Kobayashi J, Shoguchi E. Integrated omics unveil the secondary metabolic landscape of a basal dinoflagellate. BMC Biol 2020; 18:139. [PMID: 33050904 PMCID: PMC7557087 DOI: 10.1186/s12915-020-00873-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 09/18/2020] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND Some dinoflagellates cause harmful algal blooms, releasing toxic secondary metabolites, to the detriment of marine ecosystems and human health. Our understanding of dinoflagellate toxin biosynthesis has been hampered by their unusually large genomes. To overcome this challenge, for the first time, we sequenced the genome, microRNAs, and mRNA isoforms of a basal dinoflagellate, Amphidinium gibbosum, and employed an integrated omics approach to understand its secondary metabolite biosynthesis. RESULTS We assembled the ~ 6.4-Gb A. gibbosum genome, and by probing decoded dinoflagellate genomes and transcriptomes, we identified the non-ribosomal peptide synthetase adenylation domain as essential for generation of specialized metabolites. Upon starving the cells of phosphate and nitrogen, we observed pronounced shifts in metabolite biosynthesis, suggestive of post-transcriptional regulation by microRNAs. Using Iso-Seq and RNA-seq data, we found that alternative splicing and polycistronic expression generate different transcripts for secondary metabolism. CONCLUSIONS Our genomic findings suggest intricate integration of various metabolic enzymes that function iteratively to synthesize metabolites, providing mechanistic insights into how dinoflagellates synthesize secondary metabolites, depending upon nutrient availability. This study provides insights into toxin production associated with dinoflagellate blooms. The genome of this basal dinoflagellate provides important clues about dinoflagellate evolution and overcomes the large genome size, which has been a challenge previously.
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Affiliation(s)
- Girish Beedessee
- Marine Genomics Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa, 904-0495, Japan.
- Present address: Department of Biochemistry, University of Cambridge, Cambridge, CB2 1QW, UK.
| | - Takaaki Kubota
- Showa Pharmaceutical University, 3-3165 Higashi-Tamagawagakuen, Machida, Tokyo, 194-8543, Japan
| | - Asuka Arimoto
- Marine Genomics Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa, 904-0495, Japan
- Marine Biological Laboratory, Graduate School of Integrated Sciences for Life, Hiroshima University, Onomichi, Hiroshima, 722-0073, Japan
| | - Koki Nishitsuji
- Marine Genomics Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa, 904-0495, Japan
| | - Ross F Waller
- Department of Biochemistry, University of Cambridge, Cambridge, CB2 1QW, UK
| | - Kanako Hisata
- Marine Genomics Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa, 904-0495, Japan
| | - Shinichi Yamasaki
- DNA Sequencing Section, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa, 904-0495, Japan
| | - Noriyuki Satoh
- Marine Genomics Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa, 904-0495, Japan
| | - Jun'ichi Kobayashi
- Graduate School of Pharmaceutical Sciences, Hokkaido University, Sapporo, 060-0812, Japan
| | - Eiichi Shoguchi
- Marine Genomics Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa, 904-0495, Japan
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18
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Identification of Polyunsaturated Fatty Acids Synthesis Pathways in the Toxic Dinophyte Alexandrium minutum Using 13C-Labelling. Biomolecules 2020; 10:biom10101428. [PMID: 33050104 PMCID: PMC7600785 DOI: 10.3390/biom10101428] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 09/26/2020] [Accepted: 10/07/2020] [Indexed: 11/16/2022] Open
Abstract
The synthetic pathways responsible for the production of the polyunsaturated fatty acids 22:6n-3 and 20:5n-3 were studied in the Dinophyte Alexandrium minutum. The purpose of this work was to follow the progressive incorporation of an isotopic label (13CO2) into 11 fatty acids to better understand the fatty acid synthesis pathways in A. minutum. The Dinophyte growth was monitored for 54 h using high-frequency sampling. A. minutum presented a growth in two phases. A lag phase was observed during the first 30 h of development and had been associated with the probable temporary encystment of Dinophyte cells. An exponential growth phase was then observed after t30. A. minutum rapidly incorporated 13C into 22:6n-3, which ended up being the most 13C-enriched polyunsaturated fatty acid (PUFA) in this experiment, with a higher 13C atomic enrichment than 18:4n-3, 18:5n-3, 20:5n-3, and 22:5n-3. Overall, the 13C atomic enrichment (AE) was inversely proportional to number of carbons in n-3 PUFA. C18 PUFAs, 18:4n-3, and 18:5n-3, were indeed among the least 13C-enriched FAs during this experiment. They were assumed to be produced by the n-3 PUFA pathway. However, they could not be further elongated or desaturated to produce n-3 C20-C22 PUFA, because the AEs of the n-3 C18 PUFAs were lower than those of the n-3 C20-C22 PUFAs. Thus, the especially high atomic enrichment of 22:6n-3 (55.8% and 54.9% in neutral lipids (NLs) and polar lipids (PLs), respectively) led us to hypothesize that this major PUFA was synthesized by an O2-independent Polyketide Synthase (PKS) pathway. Another parallel PKS, independent of the one leading to 22:6n-3, was also supposed to produce 20:5n-3. The inverse order of the 13C atomic enrichment for n-3 PUFAs was also suspected to be related to the possible β-oxidation of long-chain n-3 PUFAs occurring during A. minutum encystment.
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19
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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] [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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20
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De novo Transcriptome of the Non-saxitoxin Producing Alexandrium tamutum Reveals New Insights on Harmful Dinoflagellates. Mar Drugs 2020; 18:md18080386. [PMID: 32722301 PMCID: PMC7460133 DOI: 10.3390/md18080386] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 07/17/2020] [Accepted: 07/20/2020] [Indexed: 12/17/2022] Open
Abstract
Many dinoflagellates species, especially of the Alexandrium genus, produce a series of toxins with tremendous impacts on human and environmental health, and tourism economies. Alexandrium tamutum was discovered for the first time in the Gulf of Naples, and it is not known to produce saxitoxins. However, a clone of A. tamutum from the same Gulf showed copepod reproduction impairment and antiproliferative activity. In this study, the full transcriptome of the dinoflagellate A. tamutum is presented in both control and phosphate starvation conditions. RNA-seq approach was used for in silico identification of transcripts that can be involved in the synthesis of toxic compounds. Phosphate starvation was selected because it is known to induce toxin production for other Alexandrium spp. Results showed the presence of three transcripts related to saxitoxin synthesis (sxtA, sxtG and sxtU), and others potentially related to the synthesis of additional toxic compounds (e.g., 44 transcripts annotated as "polyketide synthase"). These data suggest that even if this A. tamutum clone does not produce saxitoxins, it has the potential to produce toxic metabolites, in line with the previously observed activity. These data give new insights into toxic microalgae, toxin production and their potential applications for the treatment of human pathologies.
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21
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Wang H, Kim H, Ki JS. Transcriptome survey and toxin measurements reveal evolutionary modification and loss of saxitoxin biosynthesis genes in the dinoflagellates Amphidinium carterae and Prorocentrum micans. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2020; 195:110474. [PMID: 32200147 DOI: 10.1016/j.ecoenv.2020.110474] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 03/09/2020] [Accepted: 03/11/2020] [Indexed: 06/10/2023]
Abstract
In the present study, we characterized the potential toxin genes for polyketide synthase (PKS) and saxitoxin (STX) biosynthesis using the transcriptomes of two non-STX producing dinoflagellates Amphidinium carterae and Prorocentrum micans. RNA sequencing revealed 94 and 166 PKS contigs in A. carterae and P. micans, respectively. We first detected type III PKS, which was closely related to bacteria. In addition, dozens of homologs of 20 STX biosynthesis genes were identified. Interestingly, the core STX-synthesizing genes sxtA and sxtB were only found in P. micans, whereas sxtD was detected in A. carterae alone. Bioinformatic analysis showed that the first two core genes (sxtA and sxtG) had a low sequence similarity (37.0-67.6%) and different domain organization compared to those of other toxigenic dinoflagellates, such as Alexandrium pacificum. These might result in the breakdown of the initial reactions in STX production and ultimately the loss of the ability to synthesize the toxins in both dinoflagellates. Our findings suggest that toxin-related PKS and sxt genes are commonly found in non-STX producing dinoflagellates. In addition to their involvement in the synthesis of toxins, our result indicates that genes may also have other molecular metabolic functions.
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Affiliation(s)
- Hui Wang
- Department of Biotechnology, Sangmyung University, Seoul, 03016, South Korea
| | - Hansol Kim
- Department of Biotechnology, Sangmyung University, Seoul, 03016, South Korea
| | - Jang-Seu Ki
- Department of Biotechnology, Sangmyung University, Seoul, 03016, South Korea.
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22
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Wu Z, Luo H, Yu L, Lee WH, Li L, Mak YL, Lin S, Lam PKS. Characterizing ciguatoxin (CTX)- and Non-CTX-producing strains of Gambierdiscus balechii using comparative transcriptomics. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 717:137184. [PMID: 32084685 DOI: 10.1016/j.scitotenv.2020.137184] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 01/28/2020] [Accepted: 02/06/2020] [Indexed: 06/10/2023]
Abstract
Gambierdiscus spp. can produce the polyketide compound, ciguatoxin (CTX), and are hence responsible for ciguatera fish poisoning (CFP). Studying the molecular mechanism that regulates CTX production is crucial for understanding the environmental trigger of CTX as well as for better informing fishery management. Commonly, polyketide synthases are important for polyketide synthesis; however, no gene has been confirmatively assigned to CTX production. Here, suppression subtractive hybridization (SSH) and transcriptome sequencing (RNA-Seq) were used to compare a CTX-producing strain with a non-CTX-producing strain. Using both methods, a total of 52 polyketide synthase (PKS) genes were identified to be up-regulated in the CTX-producing G. balechii, including transcripts encoding single-domain PKSs as well as transcripts encoding multi-domain PKSs. Using reverse transcription quantitative PCR, the expression of these genes in the CTX-producing strain and in nitrogen-limited cultures of the strain was further documented. These data suggest that PKSs are likely involved in polyketide synthesis and potentially in CTX synthesis in this dinoflagellate species. Our study provides the candidate biomarkers for the detection of CTXs or CFP in waters or any other organisms as well as a valuable genomic resource for the research on Gambierdiscus and other dinoflagellates.
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Affiliation(s)
- Zhen Wu
- State Key Laboratory of Marine Pollution, City University of Hong Kong, Hong Kong, China; Department of Chemistry, City University of Hong Kong, Hong Kong, China
| | - Hao Luo
- State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, China
| | - Liying Yu
- State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, China
| | - Wai Hin Lee
- State Key Laboratory of Marine Pollution, City University of Hong Kong, Hong Kong, China; Department of Biomedical Sciences, City University of Hong Kong, Hong Kong, China
| | - Ling Li
- State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, China
| | - Yim Ling Mak
- State Key Laboratory of Marine Pollution, City University of Hong Kong, Hong Kong, China; Shenzhen Key Laboratory for the Sustainable Use of Marine Biodiversity, Research Centre for the Oceans and Human Health, City University of Hong Kong Shenzhen Research Institute, Shenzhen, China
| | - Senjie Lin
- State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen, China; Department of Marine Sciences, University of Connecticut, Groton, CT, USA.
| | - Paul K S Lam
- State Key Laboratory of Marine Pollution, City University of Hong Kong, Hong Kong, China; Department of Chemistry, City University of Hong Kong, Hong Kong, China; Shenzhen Key Laboratory for the Sustainable Use of Marine Biodiversity, Research Centre for the Oceans and Human Health, City University of Hong Kong Shenzhen Research Institute, Shenzhen, China
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23
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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] [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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Mining Natural Product Biosynthesis in Eukaryotic Algae. Mar Drugs 2020; 18:md18020090. [PMID: 32019095 PMCID: PMC7073580 DOI: 10.3390/md18020090] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 01/24/2020] [Accepted: 01/28/2020] [Indexed: 11/17/2022] Open
Abstract
Eukaryotic algae are an extremely diverse category of photosynthetic organisms and some species produce highly potent bioactive compounds poisonous to humans or other animals, most notably observed during harmful algal blooms. These natural products include some of the most poisonous small molecules known and unique cyclic polyethers. However, the diversity and complexity of algal genomes means that sequencing-based research has lagged behind research into more readily sequenced microbes, such as bacteria and fungi. Applying informatics techniques to the algal genomes that are now available reveals new natural product biosynthetic pathways, with different groups of algae containing different types of pathways. There is some evidence for gene clusters and the biosynthetic logic of polyketides enables some prediction of these final products. For other pathways, it is much more challenging to predict the products and there may be many gene clusters that are not identified with the automated tools. These results suggest that there is a great diversity of biosynthetic capacity for natural products encoded in the genomes of algae and suggest areas for future research focus.
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25
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Guillen PO, Jaramillo KB, Genta-Jouve G, Thomas OP. Marine natural products from zoantharians: bioactivity, biosynthesis, systematics, and ecological roles. Nat Prod Rep 2020; 37:515-540. [DOI: 10.1039/c9np00043g] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The dazzling marine zoantharians represent a reservoir of chemical diversity that remains to be unveiled. These fragile animals have so far been found to harbour the highly bioactive palytoxins or zoanthamines but also the harmless ecdysteroids or zoanthozanthins.
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Affiliation(s)
- Paul O. Guillen
- Marine Biodiscovery
- School of Chemistry and Ryan Institute
- National University of Ireland Galway (NUI Galway)
- H91 TK33 Galway
- Ireland
| | - Karla B. Jaramillo
- ESPOL Escuela Superior Politécnica del Litoral, ESPOL
- Centro Nacional de Acuacultura e Investigaciones Marinas
- Guayaquil
- Ecuador
- Zoology
| | - Grégory Genta-Jouve
- Muséum National d'Histoire Naturelle
- Unité Molécules de Communication et Adaptation des Micro-organismes (UMR 7245)
- Sorbonne Universités
- CNRS
- Paris
| | - Olivier P. Thomas
- Marine Biodiscovery
- School of Chemistry and Ryan Institute
- National University of Ireland Galway (NUI Galway)
- H91 TK33 Galway
- Ireland
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26
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Niu Z, Xu W, Na J, Lv Z, Zhang Y. How long-term exposure of environmentally relevant antibiotics may stimulate the growth of Prorocentrum lima: A probable positive factor for red tides. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 255:113149. [PMID: 31522007 DOI: 10.1016/j.envpol.2019.113149] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Revised: 07/29/2019] [Accepted: 08/30/2019] [Indexed: 06/10/2023]
Abstract
Antibiotics have been widely detected in the ocean and have various impacts on the environment, while knowledge of their chronic influence on phytoplankton, especially red tide algae, is still limited. Dinoflagellates and green algae are common phytoplankton in marine ecosystems. The former is the main red tide algae, and the latter is an important primary producer. We investigated the long-term responses of two representative algae, Prorocentrum lima and Chlorella sp., to two common antibiotics (sulfamethoxazole (SMX) and norfloxacin (NFX)) at environmentally relevant levels (10 and 100 ng/L) during simulated natural conditions. The cell density and activities of three antioxidant enzymes (superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD)) were analyzed. The results showed that the influence of each antibiotic on Chlorella sp. was not significant (p > 0.05) during the first 10 days, but the influence of the antibiotics later began to show significant inhibition (p < 0.05) compared with the control group, especially during mixed exposure. P. lima was not inhibited, but its cell density increased. SMX had a superior stimulation effect on P. lima. The three enzymes activities of P. lima increased, and the antioxidant mechanism was not seriously impacted. However, for Chlorella sp., the activity of SOD increased while the activities of CAT and POD decreased, suggesting that this algae's antioxidant system was unbalanced due to oxidative stress. Based on our results, the growth of P. lima was different from green algae Chlorella sp. as well as other inhibited marine algae (such as diatom, golden algae) studied in previous studies. Therefore, as a typical pollutant in the ocean, antibiotics may play a positive role in the bloom of dinoflagellate red tides.
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Affiliation(s)
- Zhiguang Niu
- School of Marine Science and Technology, Tianjin University, Tianjin 300072, China
| | - Wei'an Xu
- School of Marine Science and Technology, Tianjin University, Tianjin 300072, China
| | - Jing Na
- School of Marine Science and Technology, Tianjin University, Tianjin 300072, China
| | - Zhiwei Lv
- School of Marine Science and Technology, Tianjin University, Tianjin 300072, China
| | - Ying Zhang
- MOE Key Laboratory of Pollution Processes and Environmental Criteria/Tianjin Key Laboratory of Environmental Technology for Complex Trans-Media Pollution, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China.
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Meng FQ, Song JT, Zhou J, Cai ZH. Transcriptomic Profile and Sexual Reproduction-Relevant Genes of Alexandrium minutum in Response to Nutritional Deficiency. Front Microbiol 2019; 10:2629. [PMID: 31803162 PMCID: PMC6877688 DOI: 10.3389/fmicb.2019.02629] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 10/29/2019] [Indexed: 11/26/2022] Open
Abstract
Alexandrium minutum is a typical marine toxic dinoflagellate responsible for producing paralytic shellfish poisoning (PSP) toxins. Until now, we know little about the genomic information of A. minutum, so a transcriptome study was conducted to clarify the physiological adaptations related to nutritional deficiency. Here, we performed RNA-Seq analysis to assess the gene expression patterns of A. minutum under N and P deficient conditions for 0 (control), 6, and 72 h. Main differences between the control and experimental groups were observed in hydrolase activity and fatty acid, lipid, protein, and P metabolism. Activities of photosystem I (PSI) and PSII were significantly down-regulated, and the endocytosis pathway (clathrin-dependent endocytosis) was significantly enriched under N and P stress compared with the control, indicating that A. minutum shifts its trophy pattern under N and P stress. We also identified several unigenes related to the process of sexual reproduction, including sex determination, sperm-egg recognition, sex differentiation, mating, and fertilization. Approximately 50% of the successfully annotated unigenes were differentially expressed between the short-term stimulated sample (6 h) and control (R). However, the expression level of most unigenes returned to normal levels after 72 h, indicating that N and P stress plays a limited role in the induction of sexual reproduction. Furthermore, the quantitative real-time PCR (qRT-PCR) results of the five representative sex-related unigenes were consistent with sequencing data, which confirmed the authenticity of transcriptomic analysis. Also, qRT-PCR analysis showed that the long and short form transcripts of the saxitoxin biosynthesis gene (sxtA) were down-regulated under the nutrient deficient condition compared with the control, indicating that N and P stress regulates sxtA expression. Overall, transcriptome analysis of A. minutum revealed that N and P deficiency induced responses associated with stress response, photosynthetic efficiency, toxin biosynthesis, and sexual reproduction. Our data indicate that algae change their trophic modes (to facultative mixotrophy) and related physiological reactions under stress conditions; this possibly represents an ecological adaption strategy in the algal life cycle.
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Affiliation(s)
- Fan-Qiang Meng
- School of Life Sciences, Tsinghua University, Beijing, China.,Shenzhen Public Platform of Screening and Application of Marine Microbial Resources, The Shenzhen International Graduate School, Tsinghua University, Shenzhen, China
| | - Jun-Ting Song
- School of Life Sciences, Tsinghua University, Beijing, China.,Shenzhen Public Platform of Screening and Application of Marine Microbial Resources, The Shenzhen International Graduate School, Tsinghua University, Shenzhen, China
| | - Jin Zhou
- Shenzhen Public Platform of Screening and Application of Marine Microbial Resources, The Shenzhen International Graduate School, Tsinghua University, Shenzhen, China
| | - Zhong-Hua Cai
- Shenzhen Public Platform of Screening and Application of Marine Microbial Resources, The Shenzhen International Graduate School, Tsinghua University, Shenzhen, China
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28
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Verma A, Kohli GS, Harwood DT, Ralph PJ, Murray SA. Transcriptomic investigation into polyketide toxin synthesis in Ostreopsis (Dinophyceae) species. Environ Microbiol 2019; 21:4196-4211. [PMID: 31415128 DOI: 10.1111/1462-2920.14780] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Revised: 08/12/2019] [Accepted: 08/12/2019] [Indexed: 12/01/2022]
Abstract
In marine ecosystems, dinoflagellates can become highly abundant and even dominant at times, despite their comparatively slow growth. Their ecological success may be related to their production of complex toxic polyketide compounds. Ostreopsis species produce potent palytoxin-like compounds (PLTX), which are associated with human skin and eye irritations, and illnesses through the consumption of contaminated seafood. To investigate the genetic basis of PLTX-like compounds, we sequenced and annotated transcriptomes from two PLTX-producing Ostreopsis species; O. cf. ovata, O. cf. siamensis, one non-PLTX producing species, O. rhodesae and compared them to a close phylogenetic relative and non-PLTX producer, Coolia malayensis. We found no clear differences in the presence or diversity of ketosynthase and ketoreductase transcripts between PLTX producing and non-producing Ostreopsis and Coolia species, as both groups contained >90 and > 10 phylogenetically diverse ketosynthase and ketoreductase transcripts, respectively. We report for the first-time type I single-, multi-domain polyketide synthases (PKSs) and hybrid non-ribosomal peptide synthase/PKS transcripts from all species. The long multi-modular PKSs were insufficient by themselves to synthesize the large complex polyether backbone of PLTX-like compounds. This implies that numerous PKS domains, including both single and multi-, work together on the biosynthesis of PLTX-like and other related polyketide compounds.
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Affiliation(s)
- Arjun Verma
- Climate Change Cluster, University of Technology Sydney, Ultimo, New South Wales, 2007, Australia
| | - Gurjeet S Kohli
- Climate Change Cluster, University of Technology Sydney, Ultimo, New South Wales, 2007, Australia.,Alfred-Wegener-Institute Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, 27515, Germany
| | - D Tim Harwood
- Cawthron Institute, 98, Halifax Street East, Nelson, 7010, New Zealand
| | - Peter J Ralph
- Climate Change Cluster, University of Technology Sydney, Ultimo, New South Wales, 2007, Australia
| | - Shauna A Murray
- Climate Change Cluster, University of Technology Sydney, Ultimo, New South Wales, 2007, Australia
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29
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Vingiani GM, De Luca P, Ianora A, Dobson ADW, Lauritano C. Microalgal Enzymes with Biotechnological Applications. Mar Drugs 2019; 17:md17080459. [PMID: 31387272 PMCID: PMC6723882 DOI: 10.3390/md17080459] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 07/31/2019] [Accepted: 08/01/2019] [Indexed: 12/26/2022] Open
Abstract
Enzymes are essential components of biological reactions and play important roles in the scaling and optimization of many industrial processes. Due to the growing commercial demand for new and more efficient enzymes to help further optimize these processes, many studies are now focusing their attention on more renewable and environmentally sustainable sources for the production of these enzymes. Microalgae are very promising from this perspective since they can be cultivated in photobioreactors, allowing the production of high biomass levels in a cost-efficient manner. This is reflected in the increased number of publications in this area, especially in the use of microalgae as a source of novel enzymes. In particular, various microalgal enzymes with different industrial applications (e.g., lipids and biofuel production, healthcare, and bioremediation) have been studied to date, and the modification of enzymatic sequences involved in lipid and carotenoid production has resulted in promising results. However, the entire biosynthetic pathways/systems leading to synthesis of potentially important bioactive compounds have in many cases yet to be fully characterized (e.g., for the synthesis of polyketides). Nonetheless, with recent advances in microalgal genomics and transcriptomic approaches, it is becoming easier to identify sequences encoding targeted enzymes, increasing the likelihood of the identification, heterologous expression, and characterization of these enzymes of interest. This review provides an overview of the state of the art in marine and freshwater microalgal enzymes with potential biotechnological applications and provides future perspectives for this field.
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Affiliation(s)
- Giorgio Maria Vingiani
- Marine Biotechnology Department, Stazione Zoologica Anton Dohrn, CAP80121 (NA) Villa Comunale, Italy
| | - Pasquale De Luca
- Research Infrastructure for Marine Biological Resources Department, Stazione Zoologica Anton Dohrn, CAP80121 (NA) Villa Comunale, Italy
| | - Adrianna Ianora
- Marine Biotechnology Department, Stazione Zoologica Anton Dohrn, CAP80121 (NA) Villa Comunale, Italy
| | - Alan D W Dobson
- School of Microbiology, University College Cork, College Road, T12 YN60 Cork, Ireland
- Environmental Research Institute, University College Cork, Lee Road, T23XE10 Cork, Ireland
| | - Chiara Lauritano
- Marine Biotechnology Department, Stazione Zoologica Anton Dohrn, CAP80121 (NA) Villa Comunale, Italy.
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30
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Verma A, Barua A, Ruvindy R, Savela H, Ajani PA, Murray SA. The Genetic Basis of Toxin Biosynthesis in Dinoflagellates. Microorganisms 2019; 7:E222. [PMID: 31362398 PMCID: PMC6722697 DOI: 10.3390/microorganisms7080222] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2019] [Revised: 07/23/2019] [Accepted: 07/27/2019] [Indexed: 02/07/2023] Open
Abstract
In marine ecosystems, dinoflagellates can become highly abundant and even dominant at times, despite their comparatively slow growth rates. One factor that may play a role in their ecological success is the production of complex secondary metabolite compounds that can have anti-predator, allelopathic, or other toxic effects on marine organisms, and also cause seafood poisoning in humans. Our knowledge about the genes involved in toxin biosynthesis in dinoflagellates is currently limited due to the complex genomic features of these organisms. Most recently, the sequencing of dinoflagellate transcriptomes has provided us with valuable insights into the biosynthesis of polyketide and alkaloid-based toxin molecules in dinoflagellate species. This review synthesizes the recent progress that has been made in understanding the evolution, biosynthetic pathways, and gene regulation in dinoflagellates with the aid of transcriptomic and other molecular genetic tools, and provides a pathway for future studies of dinoflagellates in this exciting omics era.
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Affiliation(s)
- Arjun Verma
- Climate Change Cluster, University of Technology Sydney, Sydney 2007, Australia.
| | - Abanti Barua
- Climate Change Cluster, University of Technology Sydney, Sydney 2007, Australia
- Department of Microbiology, Noakhali Science and Technology University, Chittagong 3814, Bangladesh
| | - Rendy Ruvindy
- Climate Change Cluster, University of Technology Sydney, Sydney 2007, Australia
| | - Henna Savela
- Finnish Environment Institute, Marine Research Centre, 00790 Helsinki, Finland
| | - Penelope A Ajani
- Climate Change Cluster, University of Technology Sydney, Sydney 2007, Australia
| | - Shauna A Murray
- Climate Change Cluster, University of Technology Sydney, Sydney 2007, Australia
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31
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Martínez KA, Lauritano C, Druka D, Romano G, Grohmann T, Jaspars M, Martín J, Díaz C, Cautain B, de la Cruz M, Ianora A, Reyes F. Amphidinol 22, a New Cytotoxic and Antifungal Amphidinol from the Dinoflagellate Amphidinium carterae. Mar Drugs 2019; 17:md17070385. [PMID: 31252576 PMCID: PMC6669446 DOI: 10.3390/md17070385] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 06/20/2019] [Accepted: 06/24/2019] [Indexed: 12/27/2022] Open
Abstract
Due to the unique biodiversity and the physical-chemical properties of their environment, marine microorganisms have evolved defense and signaling compounds that often have no equivalent in terrestrial habitats. The aim of this study was to screen extracts of the dinoflagellate Amphidinium carterae for possible bioactivities (i.e., anticancer, anti-inflammatory, anti-diabetes, antibacterial and antifungal properties) and identify bioactive compounds. Anticancer activity was evaluated on human lung adenocarcinoma (A549), human skin melanoma (A2058), human hepatocellular carcinoma (HepG2), human breast adenocarcinoma (MCF7) and human pancreas carcinoma (MiaPaca-2) cell lines. Antimicrobial activities were evaluated against Gram-positive bacteria (Staphylococcus aureus MRSA and MSSA), Gram-negative bacteria (i.e., Escherichia coli and Klebsiella pneumoniae), Mycobacterium tuberculosis and the fungus Aspergillus fumigatus. The results indicated moderate biological activities against all the cancer cells lines and microorganisms tested. Bioassay-guided fractionation assisted by HRMS analysis allowed the detection of one new and two known amphidinols that are potentially responsible for the antifungal and cytotoxic activities observed. Further isolation, purification and structural elucidation led to a new amphidinol, named amphidinol 22. The planar structure of the new compound was determined by analysis of its HRMS and 1D and 2D NMR spectra. Its biological activity was evaluated, and it displayed both anticancer and antifungal activities.
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Affiliation(s)
- Kevin A Martínez
- Department of Marine Biotechnology, Stazione Zoologica Anton Dohrn, 80121 Naples, Italy
| | - Chiara Lauritano
- Department of Marine Biotechnology, Stazione Zoologica Anton Dohrn, 80121 Naples, Italy.
| | - Dana Druka
- Marine Biodiscovery Centre, Department of Chemistry, University of Aberdeen, Aberdeen AB24 3UE, Scotland, UK
| | - Giovanna Romano
- Department of Marine Biotechnology, Stazione Zoologica Anton Dohrn, 80121 Naples, Italy
| | - Teresa Grohmann
- The Rowett Institute, University of Aberdeen, Aberdeen AB25 2ZD, Scotland, UK
| | - Marcel Jaspars
- Marine Biodiscovery Centre, Department of Chemistry, University of Aberdeen, Aberdeen AB24 3UE, Scotland, UK
| | - Jesús Martín
- Fundación MEDINA, Centro de Excelencia en Investigación de Medicamentos Innovadores en Andalucía, Avda. del Conocimiento 34, 18016 Granada, Spain
| | - Caridad Díaz
- Fundación MEDINA, Centro de Excelencia en Investigación de Medicamentos Innovadores en Andalucía, Avda. del Conocimiento 34, 18016 Granada, Spain
| | - Bastien Cautain
- Fundación MEDINA, Centro de Excelencia en Investigación de Medicamentos Innovadores en Andalucía, Avda. del Conocimiento 34, 18016 Granada, Spain
| | - Mercedes de la Cruz
- Fundación MEDINA, Centro de Excelencia en Investigación de Medicamentos Innovadores en Andalucía, Avda. del Conocimiento 34, 18016 Granada, Spain
| | - Adrianna Ianora
- Department of Marine Biotechnology, Stazione Zoologica Anton Dohrn, 80121 Naples, Italy
| | - Fernando Reyes
- Fundación MEDINA, Centro de Excelencia en Investigación de Medicamentos Innovadores en Andalucía, Avda. del Conocimiento 34, 18016 Granada, Spain
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Abstract
Enzyme-mediated cascade reactions are widespread in biosynthesis. To facilitate comparison with the mechanistic categorizations of cascade reactions by synthetic chemists and delineate the common underlying chemistry, we discuss four types of enzymatic cascade reactions: those involving nucleophilic, electrophilic, pericyclic, and radical reactions. Two subtypes of enzymes that generate radical cascades exist at opposite ends of the oxygen abundance spectrum. Iron-based enzymes use O2 to generate high valent iron-oxo species to homolyze unactivated C-H bonds in substrates to initiate skeletal rearrangements. At anaerobic end, enzymes reversibly cleave S-adenosylmethionine (SAM) to generate the 5'-deoxyadenosyl radical as a powerful oxidant to initiate C-H bond homolysis in bound substrates. The latter enzymes are termed radical SAM enzymes. We categorize the former as "thwarted oxygenases".
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Affiliation(s)
- Christopher T Walsh
- Stanford University Chemistry, Engineering, and Medicine for Human Health (CheM-H), Stanford University, Stanford, CA, 94305, USA
| | - Bradley S Moore
- Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA, 92093, USA
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA, 92093, USA
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Marine Natural Products from Microalgae: An -Omics Overview. Mar Drugs 2019; 17:md17050269. [PMID: 31067655 PMCID: PMC6562964 DOI: 10.3390/md17050269] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 04/30/2019] [Accepted: 05/04/2019] [Indexed: 12/19/2022] Open
Abstract
Over the last decade, genome sequences and other -omics datasets have been produced for a wide range of microalgae, and several others are on the way. Marine microalgae possess distinct and unique metabolic pathways, and can potentially produce specific secondary metabolites with biological activity (e.g., antipredator, allelopathic, antiproliferative, cytotoxic, anticancer, photoprotective, as well as anti-infective and antifouling activities). Because microalgae are very diverse, and adapted to a broad variety of environmental conditions, the chances to find novel and unexplored bioactive metabolites with properties of interest for biotechnological and biomedical applications are high. This review presents a comprehensive overview of the current efforts and of the available solutions to produce, explore and exploit -omics datasets, with the aim of identifying species and strains with the highest potential for the identification of novel marine natural products. In addition, funding efforts for the implementation of marine microalgal -omics resources and future perspectives are presented as well.
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Chikwililwa C, McCarron P, Waniek JJ, Schulz-Bull DE. Phylogenetic analysis and yessotoxin profiles of Gonyaulax spinifera cultures from the Benguela Current upwelling system. HARMFUL ALGAE 2019; 85:101626. [PMID: 31810531 DOI: 10.1016/j.hal.2019.101626] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 05/29/2019] [Accepted: 06/05/2019] [Indexed: 06/10/2023]
Abstract
The Benguela Current in the Atlantic is one of the four major upwelling systems on the Eastern boundary of the world ocean. Thus the coastal regions off Namibia are prone to high primary productivity that can lead to Harmful Algae Blooms as this nutrient rich water reaches the euphotic zone. Yessotoxins (YTXs) produced by G. spinifera were detected in Namibian phytoplankton field samples in 2011. Isolation of G. spinifera cultures from this location in 2012 enabled molecular genetics work and further liquid chromatography-mass spectrometry assessment of toxin profiles. The molecular work grouped the Benguela G. spinifera with other toxic G. spinifera strains originating from Italy and New Zealand. The main YTX analogs present in the Benguela G. spinifera are homo-YTX, YTX and a hydroxylated analogue. This work adds important knowledge on the occurrence of Harmful Algae Blooms in this region and is of relevance for safety.
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Affiliation(s)
- Chibo Chikwililwa
- Ministry of Fisheries and Marine Resources, National Marine Information and Research Centre, Aquaculture Directorate, Strand Street, PO Box 912, Swakopmund, Namibia; Leibniz Institute for Baltic Sea Research Warnemünde (IOW), Seestrasse 15, D-18119 Rostock, Germany; Microalgae and Seaweed Research and Development, Sam Nujoma Campus Henties Bay, University of Namibia, Private Bag 13301, 340 Mandume Ndemufayo Ave, Pionierspark, Windhoek, Namibia
| | - Pearse McCarron
- Biotoxin Metrology, National Research Council Canada, 1411 Oxford Street, Halifax, Nova Scotia, B3H 3Z1, Canada
| | - Joanna J Waniek
- Leibniz Institute for Baltic Sea Research Warnemünde (IOW), Seestrasse 15, D-18119 Rostock, Germany.
| | - Detlef E Schulz-Bull
- Leibniz Institute for Baltic Sea Research Warnemünde (IOW), Seestrasse 15, D-18119 Rostock, Germany
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35
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Affiliation(s)
- Christopher T. Walsh
- Stanford University Chemistry, Engineering, and Medicine for Human Health (CheM-H)Stanford University Stanford CA 94305 USA
| | - Bradley S. Moore
- Center for Marine Biotechnology and BiomedicineScripps Institution of OceanographyUniversity of California, San Diego La Jolla CA 92093 USA
- Skaggs School of Pharmacy and Pharmaceutical SciencesUniversity of California, San Diego La Jolla CA 92093 USA
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36
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Beedessee G, Hisata K, Roy MC, Van Dolah FM, Satoh N, Shoguchi E. Diversified secondary metabolite biosynthesis gene repertoire revealed in symbiotic dinoflagellates. Sci Rep 2019; 9:1204. [PMID: 30718591 PMCID: PMC6361889 DOI: 10.1038/s41598-018-37792-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Accepted: 12/13/2018] [Indexed: 11/09/2022] Open
Abstract
Symbiodiniaceae dinoflagellates possess smaller nuclear genomes than other dinoflagellates and produce structurally specialized, biologically active, secondary metabolites. Till date, little is known about the evolution of secondary metabolism in dinoflagellates as comparative genomic approaches have been hampered by their large genome sizes. Here, we overcome this challenge by combining genomic and metabolomics approaches to investigate how chemical diversity arises in three decoded Symbiodiniaceae genomes (clades A3, B1 and C). Our analyses identify extensive diversification of polyketide synthase and non-ribosomal peptide synthetase genes from two newly decoded genomes of Symbiodinium tridacnidorum (A3) and Cladocopium sp. (C). Phylogenetic analyses indicate that almost all the gene families are derived from lineage-specific gene duplications in all three clades, suggesting divergence for environmental adaptation. Few metabolic pathways are conserved among the three clades and we detect metabolic similarity only in the recently diverged clades, B1 and C. We establish that secondary metabolism protein architecture guides substrate specificity and that gene duplication and domain shuffling have resulted in diversification of secondary metabolism genes.
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Affiliation(s)
- Girish Beedessee
- Marine Genomics Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa, 904-0495, Japan.
| | - Kanako Hisata
- Marine Genomics Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa, 904-0495, Japan
| | - Michael C Roy
- Instrumental Analysis Section, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa, 904-0495, Japan
| | - Frances M Van Dolah
- College of Charleston, School of Sciences and Mathematics, 66 George St., Charleston, South Carolina, 29424, USA
| | - Noriyuki Satoh
- Marine Genomics Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa, 904-0495, Japan
| | - Eiichi Shoguchi
- Marine Genomics Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa, 904-0495, Japan.
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The Marine Dinoflagellate Alexandrium minutum Activates a Mitophagic Pathway in Human Lung Cancer Cells. Mar Drugs 2018; 16:md16120502. [PMID: 30545093 PMCID: PMC6316568 DOI: 10.3390/md16120502] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Revised: 12/07/2018] [Accepted: 12/10/2018] [Indexed: 12/31/2022] Open
Abstract
Marine dinoflagellates are a valuable source of bioactive molecules. Many species produce cytotoxic compounds and some of these compounds have also been investigated for their anticancer potential. Here, we report the first investigation of the toxic dinoflagellate Alexandrium minutum as source of water-soluble compounds with antiproliferative activity against human lung cancer cells. A multi-step enrichment of the phenol–water extract yielded a bioactive fraction with specific antiproliferative effect (IC50 = 0.4 µg·mL−1) against the human lung adenocarcinoma cells (A549 cell line). Preliminary characterization of this material suggested the presence of glycoprotein with molecular weight above 20 kDa. Interestingly, this fraction did not exhibit any cytotoxicity against human normal lung fibroblasts (WI38). Differential gene expression analysis in A549 cancer cells suggested that the active fraction induces specific cell death, triggered by mitochondrial autophagy (mitophagy). In agreement with the cell viability results, gene expression data also showed that no mitophagic event was activated in normal cells WI38.
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38
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Core genes in diverse dinoflagellate lineages include a wealth of conserved dark genes with unknown functions. Sci Rep 2018; 8:17175. [PMID: 30464192 PMCID: PMC6249206 DOI: 10.1038/s41598-018-35620-z] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 11/08/2018] [Indexed: 01/30/2023] Open
Abstract
Dinoflagellates are a diverse group of unicellular primary producers and grazers that exhibit some of the most remarkable features known among eukaryotes. These include gigabase-sized nuclear genomes, permanently condensed chromosomes and highly reduced organelle DNA. However, the genetic inventory that allows dinoflagellates to thrive in diverse ecological niches is poorly characterised. Here we systematically assess the functional capacity of 3,368,684 predicted proteins from 47 transcriptome datasets spanning eight dinoflagellate orders. We find that 1,232,023 proteins do not share significant sequence similarity to known sequences, i.e. are "dark". Of these, we consider 441,006 (13.1% of overall proteins) that are found in multiple taxa, or occur as alternative splice variants, to comprise the high-confidence dark proteins. Even with unknown function, 43.3% of these dark proteins can be annotated with conserved structural features using an exhaustive search against available data, validating their existence and importance. Furthermore, these dark proteins and their putative homologs are largely lineage-specific and recovered in multiple taxa. We also identified conserved functions in all dinoflagellates, and those specific to toxin-producing, symbiotic, and cold-adapted lineages. Our results demonstrate the remarkable divergence of gene functions in dinoflagellates, and provide a platform for investigations into the diversification of these ecologically important organisms.
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39
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Zuo Z, Yang Y, Xu Q, Yang W, Zhao J, Zhou L. Effects of phosphorus sources on volatile organic compound emissions from Microcystis flos-aquae and their toxic effects on Chlamydomonas reinhardtii. ENVIRONMENTAL GEOCHEMISTRY AND HEALTH 2018; 40:1283-1298. [PMID: 29264818 DOI: 10.1007/s10653-017-0055-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Accepted: 12/12/2017] [Indexed: 06/07/2023]
Abstract
There is diverse phosphorus (P) in eutrophicated waters, but it is considered as a crucial nutrient for cyanobacteria growth due to its easy precipitation as insoluble salts. To uncover the effects of complex P nutrients on the emission of volatile organic compounds (VOCs) from cyanobacteria and their toxic effects on other algae, the VOCs from Microcystis flos-aquae supplied with different types and amount of P nutrients were analyzed, and the effects of VOCs and their two main compounds on Chlamydomonas reinhardtii growth were investigated. When M. flos-aquae cells were supplied with K2HPO4, sodium pyrophosphate and sodium hexametaphosphate as the sole P source, 27, 23 and 29 compounds were found, respectively, including furans, sulfocompounds, terpenoids, benzenes, aldehydes, hydrocarbons and esters. With K2HPO4 as the sole P source, the VOC emission increased with reducing P amount, and the maximum emission was found under Non-P condition. In the treatments of M. flos-aquae VOCs under Non-P condition and two main terpenoids (eucalyptol and limonene) in the VOCs, remarkable decreases were found in C. reinhardtii cell growth, photosynthetic pigment content and photosynthetic abilities. Therefore, we deduce that multiple P nutrients in eutrophicated waters induce different VOC emissions from cyanobacteria, and P amount reduction caused by natural precipitation and algal massive growth results in more VOC emissions. These VOCs play toxic roles in cyanobacteria becoming dominant species, and eucalyptol and limonene are two toxic agents.
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Affiliation(s)
- Zhaojiang Zuo
- School of Forestry and Biotechnology, Zhejiang Agriculture and Forestry University, Hangzhou, 311300, China.
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, 48824, USA.
| | - Youyou Yang
- College of Agriculture and Food Science, Zhejiang Agriculture and Forestry University, Hangzhou, 311300, China
| | - Qinghuan Xu
- School of Forestry and Biotechnology, Zhejiang Agriculture and Forestry University, Hangzhou, 311300, China
| | - Wangting Yang
- School of Forestry and Biotechnology, Zhejiang Agriculture and Forestry University, Hangzhou, 311300, China
| | - Jingxian Zhao
- School of Forestry and Biotechnology, Zhejiang Agriculture and Forestry University, Hangzhou, 311300, China
| | - Lv Zhou
- School of Forestry and Biotechnology, Zhejiang Agriculture and Forestry University, Hangzhou, 311300, China
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40
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Musiol-Kroll EM, Wohlleben W. Acyltransferases as Tools for Polyketide Synthase Engineering. Antibiotics (Basel) 2018; 7:antibiotics7030062. [PMID: 30022008 PMCID: PMC6164871 DOI: 10.3390/antibiotics7030062] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2018] [Revised: 07/14/2018] [Accepted: 07/16/2018] [Indexed: 12/16/2022] Open
Abstract
Polyketides belong to the most valuable natural products, including diverse bioactive compounds, such as antibiotics, anticancer drugs, antifungal agents, immunosuppressants and others. Their structures are assembled by polyketide synthases (PKSs). Modular PKSs are composed of modules, which involve sets of domains catalysing the stepwise polyketide biosynthesis. The acyltransferase (AT) domains and their “partners”, the acyl carrier proteins (ACPs), thereby play an essential role. The AT loads the building blocks onto the “substrate acceptor”, the ACP. Thus, the AT dictates which building blocks are incorporated into the polyketide structure. The precursor- and occasionally the ACP-specificity of the ATs differ across the polyketide pathways and therefore, the ATs contribute to the structural diversity within this group of complex natural products. Those features make the AT enzymes one of the most promising tools for manipulation of polyketide assembly lines and generation of new polyketide compounds. However, the AT-based PKS engineering is still not straightforward and thus, rational design of functional PKSs requires detailed understanding of the complex machineries. This review summarizes the attempts of PKS engineering by exploiting the AT attributes for the modification of polyketide structures. The article includes 253 references and covers the most relevant literature published until May 2018.
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Affiliation(s)
- Ewa Maria Musiol-Kroll
- Interfakultäres Institut für Mikrobiologie und Infektionsmedizin, Eberhard Karls Universität Tübingen, Auf der Morgenstelle 28, 72076 Tübingen, Germany.
| | - Wolfgang Wohlleben
- Interfakultäres Institut für Mikrobiologie und Infektionsmedizin, Eberhard Karls Universität Tübingen, Auf der Morgenstelle 28, 72076 Tübingen, Germany.
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41
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Heimerl N, Hommel E, Westermann M, Meichsner D, Lohr M, Hertweck C, Grossman AR, Mittag M, Sasso S. A giant type I polyketide synthase participates in zygospore maturation in Chlamydomonas reinhardtii. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2018; 95:268-281. [PMID: 29729034 DOI: 10.1111/tpj.13948] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Revised: 04/14/2018] [Accepted: 04/23/2018] [Indexed: 06/08/2023]
Abstract
Polyketide synthases (PKSs) occur in many bacteria, fungi and plants. They are highly versatile enzymes involved in the biosynthesis of a large variety of compounds including antimicrobial agents, polymers associated with bacterial cell walls and plant pigments. While harmful algae are known to produce polyketide toxins, sequences of the genomes of non-toxic algae, including those of many green algal species, have surprisingly revealed the presence of genes encoding type I PKSs. The genome of the model alga Chlamydomonas reinhardtii (Chlorophyta) contains a single type I PKS gene, designated PKS1 (Cre10.g449750), which encodes a giant PKS with a predicted mass of 2.3 MDa. Here, we show that PKS1 is induced in 2-day-old zygotes and is required for their development into zygospores, the dormant stage of the zygote. Wild-type zygospores contain knob-like structures (~50 nm diameter) that form at the cell surface and develop a central cell wall layer; both of these structures are absent from homozygous pks1 mutants. Additionally, in contrast to wild-type zygotes, chlorophyll degradation is delayed in homozygous pks1 mutant zygotes, indicating a disruption in zygospore development. In agreement with the role of the PKS in the formation of the highly resistant zygospore wall, mutant zygotes have lost the formidable desiccation tolerance of wild-type zygotes. Together, our results represent functional analyses of a PKS mutant in a photosynthetic eukaryotic microorganism, revealing a central function for polyketides in the sexual cycle and survival under stressful environmental conditions.
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Affiliation(s)
- Natalie Heimerl
- Matthias Schleiden Institute of Genetics, Bioinformatics and Molecular Botany, Friedrich Schiller University, Jena, Germany
| | - Elisabeth Hommel
- Matthias Schleiden Institute of Genetics, Bioinformatics and Molecular Botany, Friedrich Schiller University, Jena, Germany
| | | | - Doreen Meichsner
- Matthias Schleiden Institute of Genetics, Bioinformatics and Molecular Botany, Friedrich Schiller University, Jena, Germany
| | - Martin Lohr
- Institute of Molecular Physiology, Plant Biochemistry, Johannes Gutenberg University, Mainz, Germany
| | - Christian Hertweck
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Jena, Germany
- Friedrich Schiller University, Jena, Germany
| | | | - Maria Mittag
- Matthias Schleiden Institute of Genetics, Bioinformatics and Molecular Botany, Friedrich Schiller University, Jena, Germany
| | - Severin Sasso
- Matthias Schleiden Institute of Genetics, Bioinformatics and Molecular Botany, Friedrich Schiller University, Jena, Germany
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Jena, Germany
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42
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Meng A, Corre E, Probert I, Gutierrez-Rodriguez A, Siano R, Annamale A, Alberti A, Da Silva C, Wincker P, Le Crom S, Not F, Bittner L. Analysis of the genomic basis of functional diversity in dinoflagellates using a transcriptome-based sequence similarity network. Mol Ecol 2018; 27:2365-2380. [PMID: 29624751 DOI: 10.1111/mec.14579] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Revised: 02/23/2018] [Accepted: 03/21/2018] [Indexed: 02/06/2023]
Abstract
Dinoflagellates are one of the most abundant and functionally diverse groups of eukaryotes. Despite an overall scarcity of genomic information for dinoflagellates, constantly emerging high-throughput sequencing resources can be used to characterize and compare these organisms. We assembled de novo and processed 46 dinoflagellate transcriptomes and used a sequence similarity network (SSN) to compare the underlying genomic basis of functional features within the group. This approach constitutes the most comprehensive picture to date of the genomic potential of dinoflagellates. A core-predicted proteome composed of 252 connected components (CCs) of putative conserved protein domains (pCDs) was identified. Of these, 206 were novel and 16 lacked any functional annotation in public databases. Integration of functional information in our network analyses allowed investigation of pCDs specifically associated with functional traits. With respect to toxicity, sequences homologous to those of proteins found in species with toxicity potential (e.g., sxtA4 and sxtG) were not specific to known toxin-producing species. Although not fully specific to symbiosis, the most represented functions associated with proteins involved in the symbiotic trait were related to membrane processes and ion transport. Overall, our SSN approach led to identification of 45,207 and 90,794 specific and constitutive pCDs of, respectively, the toxic and symbiotic species represented in our analyses. Of these, 56% and 57%, respectively (i.e., 25,393 and 52,193 pCDs), completely lacked annotation in public databases. This stresses the extent of our lack of knowledge, while emphasizing the potential of SSNs to identify candidate pCDs for further functional genomic characterization.
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Affiliation(s)
- Arnaud Meng
- Sorbonne Universités, UPMC Univ Paris 06, Univ Antilles Guyane, Univ Nice Sophia Antipolis, CNRS, Evolution Paris Seine - Institut de Biologie Paris Seine (EPS - IBPS), Paris, France
| | - Erwan Corre
- CNRS, UPMC, FR2424, ABiMS, Station Biologique, Roscoff, France
| | - Ian Probert
- UPMC-CNRS, FR2424, Roscoff Culture Collection, Station Biologique de Roscoff, Place Georges Teissier, Roscoff, France
| | | | - Raffaele Siano
- Ifremer - Centre de Brest, DYNECO PELAGOS, Plouzané, France
| | - Anita Annamale
- CEA - Institut de Génomique, GENOSCOPE, Evry, France.,CNRS, UMR8030, Evry, France.,Université d'Evry Val d'Essonne, Evry, France
| | - Adriana Alberti
- CEA - Institut de Génomique, GENOSCOPE, Evry, France.,CNRS, UMR8030, Evry, France.,Université d'Evry Val d'Essonne, Evry, France
| | - Corinne Da Silva
- CEA - Institut de Génomique, GENOSCOPE, Evry, France.,CNRS, UMR8030, Evry, France.,Université d'Evry Val d'Essonne, Evry, France
| | - Patrick Wincker
- CEA - Institut de Génomique, GENOSCOPE, Evry, France.,CNRS, UMR8030, Evry, France.,Université d'Evry Val d'Essonne, Evry, France
| | - Stéphane Le Crom
- Sorbonne Universités, UPMC Univ Paris 06, Univ Antilles Guyane, Univ Nice Sophia Antipolis, CNRS, Evolution Paris Seine - Institut de Biologie Paris Seine (EPS - IBPS), Paris, France
| | - Fabrice Not
- CNRS, UMR 7144, Station Biologique de Roscoff, Place Georges Teissier, Roscoff, France
| | - Lucie Bittner
- Sorbonne Universités, UPMC Univ Paris 06, Univ Antilles Guyane, Univ Nice Sophia Antipolis, CNRS, Evolution Paris Seine - Institut de Biologie Paris Seine (EPS - IBPS), Paris, France
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43
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Sadhukhan S, Baire B. An Unprecedented (Semi)Favorskii Rearrangement. Evidence for the 2-(Acyloxy)cyclopropanones. Org Lett 2018; 20:1748-1751. [DOI: 10.1021/acs.orglett.8b00218] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Santu Sadhukhan
- Department of Chemistry, Indian Institute of Technology Madras, Chennai, Tamilnadu 600036, India
| | - Beeraiah Baire
- Department of Chemistry, Indian Institute of Technology Madras, Chennai, Tamilnadu 600036, India
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44
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Current Knowledge and Recent Advances in Marine Dinoflagellate Transcriptomic Research. JOURNAL OF MARINE SCIENCE AND ENGINEERING 2018. [DOI: 10.3390/jmse6010013] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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45
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Assunção J, Guedes AC, Malcata FX. Biotechnological and Pharmacological Applications of Biotoxins and Other Bioactive Molecules from Dinoflagellates. Mar Drugs 2017; 15:E393. [PMID: 29261163 PMCID: PMC5742853 DOI: 10.3390/md15120393] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Revised: 12/12/2017] [Accepted: 12/15/2017] [Indexed: 12/26/2022] Open
Abstract
The long-lasting interest in bioactive molecules (namely toxins) produced by (microalga) dinoflagellates has risen in recent years. Exhibiting wide diversity and complexity, said compounds are well-recognized for their biological features, with great potential for use as pharmaceutical therapies and biological research probes. Unfortunately, provision of those compounds is still far from sufficient, especially in view of an increasing demand for preclinical testing. Despite the difficulties to establish dinoflagellate cultures and obtain reasonable productivities of such compounds, intensive research has permitted a number of advances in the field. This paper accordingly reviews the characteristics of some of the most important biotoxins (and other bioactive substances) produced by dinoflagellates. It also presents and discusses (to some length) the main advances pertaining to dinoflagellate production, from bench to large scale-with an emphasis on material published since the latest review available on the subject. Such advances encompass improvements in nutrient formulation and light supply as major operational conditions; they have permitted adaptation of classical designs, and aided the development of novel configurations for dinoflagellate growth-even though shearing-related issues remain a major challenge.
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Affiliation(s)
- Joana Assunção
- LEPABE-Laboratory of Process Engineering, Environment, Biotechnology and Energy, Rua Dr. Roberto Frias, s/n, P-4200-465 Porto, Portugal.
| | - A Catarina Guedes
- Interdisciplinary Centre of Marine and Environmental Research (CIIMAR), University of Porto, Terminal de Cruzeiros do Porto de Leixões, Avenida General Norton de Matos, s/n, P-4450-208 Matosinhos, Portugal.
| | - F Xavier Malcata
- LEPABE-Laboratory of Process Engineering, Environment, Biotechnology and Energy, Rua Dr. Roberto Frias, s/n, P-4200-465 Porto, Portugal.
- Department of Chemical Engineering, University of Porto, Rua Dr. Roberto Frias, s/n, P-4200-465 Porto, Portugal.
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46
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Van Dolah FM, Kohli GS, Morey JS, Murray SA. Both modular and single-domain Type I polyketide synthases are expressed in the brevetoxin-producing dinoflagellate, Karenia brevis (Dinophyceae). JOURNAL OF PHYCOLOGY 2017; 53:1325-1339. [PMID: 28949419 PMCID: PMC5725682 DOI: 10.1111/jpy.12586] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 09/14/2017] [Indexed: 05/09/2023]
Abstract
Dinoflagellates are prolific producers of polyketide compounds, many of which are potent toxins with adverse impacts on human and marine animal health. To identify polyketide synthase (PKS) genes in the brevetoxin-producing dinoflagellate, Karenia brevis, we assembled a transcriptome from 595 million Illumina reads, sampled under different growth conditions. The assembly included 125,687 transcripts greater than 300 nt in length, with over half having >100× coverage. We found 121 transcripts encoding Type I ketosynthase (KS) domains, of which 99 encoded single KS domains, while 22 contained multiple KS domains arranged in 1-3 protein modules. Phylogenetic analysis placed all single domain and a majority of multidomain KSs within a monophyletic clade of protist PKSs. In contrast with the highly amplified single-domain KSs, only eight single-domain ketoreductase transcripts were found in the assembly, suggesting that they are more evolutionarily conserved. The multidomain PKSs were dominated by trans-acyltransferase architectures, which were recently shown to be prevalent in other algal protists. Karenia brevis also expressed several hybrid nonribosomal peptide synthetase (NRPS)/PKS sequences, including a burA-like sequence previously reported in a wide variety of dinoflagellates. This contrasts with a similarly deep transcriptome of Gambierdiscus polynesiensis, which lacked NRPS/PKS other than the burA-like transcript, and may reflect the presence of amide-containing polyketides in K. brevis and their absence from G. polynesiensis. In concert with other recent transcriptome analyses, this study provides evidence for both single domain and multidomain PKSs in the synthesis of polyketide compounds in dinoflagellates.
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Affiliation(s)
- Frances M. Van Dolah
- College of CharlestonSchool of Sciences and Mathematics66 George St.CharlestonSouth Carolina29424USA
- Hollings Marine Laboratory331 Fort Johnson Rd.CharlestonSouth Carolina29412USA
| | - Gurjeet S. Kohli
- Climate Change ClusterUniversity of Technology Sydney15 Broadway, UltimoSydneyNew South Wales2007Australia
- Singapore Centre for Environmental Life Sciences EngineeringNanyang Technological UniversitySingapore689528
| | - Jeanine S. Morey
- Hollings Marine Laboratory331 Fort Johnson Rd.CharlestonSouth Carolina29412USA
- JHT Incorporated2710 Discovery Dr.OrlandoFlorida32826USA
| | - Shauna A. Murray
- Climate Change ClusterUniversity of Technology Sydney15 Broadway, UltimoSydneyNew South Wales2007Australia
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47
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Lauritano C, De Luca D, Ferrarini A, Avanzato C, Minio A, Esposito F, Ianora A. De novo transcriptome of the cosmopolitan dinoflagellate Amphidinium carterae to identify enzymes with biotechnological potential. Sci Rep 2017; 7:11701. [PMID: 28916825 PMCID: PMC5601461 DOI: 10.1038/s41598-017-12092-1] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Accepted: 09/04/2017] [Indexed: 01/17/2023] Open
Abstract
Dinoflagellates are phytoplanktonic organisms found in both freshwater and marine habitats. They are often studied because related to harmful algal blooms but they are also known to produce bioactive compounds for the treatment of human pathologies. The aim of this study was to sequence the full transcriptome of the dinoflagellate Amphidinium carterae in both nitrogen-starved and -replete culturing conditions (1) to evaluate the response to nitrogen starvation at the transcriptional level, (2) to look for possible polyketide synthases (PKSs) in the studied clone (genes that may be involved in the synthesis of bioactive compounds), (3) if present, to evaluate if nutrient starvation can influence PKS expression, (4) to look for other possible enzymes of biotechnological interest and (5) to test strain cytotoxicity on human cell lines. Results showed an increase in nitrogen metabolism and stress response in nitrogen-starved cells and confirmed the presence of a type I β-ketosynthase. In addition, L-asparaginase (used for the treatment of Leukemia and for acrylamide reduction in food industries) and cellulase (useful for biofuel production and other industrial applications) have been identified for the first time in this species, giving new insights into possible biotechnological applications of dinoflagellates.
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Affiliation(s)
- Chiara Lauritano
- Integrative Marine Ecology Department, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121, Napoli, Italy.
| | - Daniele De Luca
- Integrative Marine Ecology Department, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121, Napoli, Italy
| | - Alberto Ferrarini
- Università degli Studi di Verona, Ca' Vignal 1, Strada Le Grazie 15, 37134, Verona, Italy
| | - Carla Avanzato
- Università degli Studi di Verona, Ca' Vignal 1, Strada Le Grazie 15, 37134, Verona, Italy
| | - Andrea Minio
- Università degli Studi di Verona, Ca' Vignal 1, Strada Le Grazie 15, 37134, Verona, Italy
| | - Francesco Esposito
- Integrative Marine Ecology Department, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121, Napoli, Italy
| | - Adrianna Ianora
- Integrative Marine Ecology Department, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121, Napoli, Italy
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48
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Romano G, Costantini M, Sansone C, Lauritano C, Ruocco N, Ianora A. Marine microorganisms as a promising and sustainable source of bioactive molecules. MARINE ENVIRONMENTAL RESEARCH 2017; 128:58-69. [PMID: 27160988 DOI: 10.1016/j.marenvres.2016.05.002] [Citation(s) in RCA: 103] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Revised: 04/29/2016] [Accepted: 05/01/2016] [Indexed: 06/05/2023]
Abstract
There is an urgent need to discover new drug entities due to the increased incidence of severe diseases as cancer and neurodegenerative pathologies, and reducing efficacy of existing antibiotics. Recently, there is a renewed interest in exploring the marine habitat for new pharmaceuticals also thanks to the advancement in cultivation technologies and in molecular biology techniques. Microorganisms represent a still poorly explored resource for drug discovery. The possibility of obtaining a continuous source of bioactives from marine microorganisms, more amenable to culturing compared to macro-organisms, may be able to meet the challenging demands of pharmaceutical industries. This would enable a more environmentally-friendly approach to drug discovery and overcome the over-utilization of marine resources and the use of destructive collection practices. The importance of the topic is underlined by the number of EU projects funded aimed at improving the exploitation of marine organisms for drug discovery.
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Affiliation(s)
- G Romano
- Department of Integrative Marine Ecology, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Napoli, Italy.
| | - M Costantini
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Napoli, Italy
| | - C Sansone
- Department of Integrative Marine Ecology, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Napoli, Italy
| | - C Lauritano
- Department of Integrative Marine Ecology, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Napoli, Italy
| | - N Ruocco
- Department of Biology and Evolution of Marine Organisms, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Napoli, Italy; Department of Biology, University of Naples Federico II, Complesso Universitario di Monte Sant'Angelo, Via Cinthia, 80126 Napoli, Italy; Bio-Organic Chemistry Unit, Institute of Biomolecular Chemistry-CNR, Via Campi Flegrei 34, Pozzuoli, Naples 80078, Italy
| | - A Ianora
- Department of Integrative Marine Ecology, Stazione Zoologica Anton Dohrn, Villa Comunale, 80121 Napoli, Italy
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The Missing Piece in Biosynthesis of Amphidinols: First Evidence of Glycolate as a Starter Unit in New Polyketides from Amphidinium carterae. Mar Drugs 2017; 15:md15060157. [PMID: 28561749 PMCID: PMC5484107 DOI: 10.3390/md15060157] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Revised: 05/22/2017] [Accepted: 05/25/2017] [Indexed: 11/23/2022] Open
Abstract
Two new members of the amphidinol family, amphidinol A (1) and its 7-sulfate derivative amphidinol B (2), were isolated from a strain of Amphidinium carterae of Lake Fusaro, near Naples (Italy), and chemically identified by spectroscopic and spectrometric methods. Amphidinol A showed antifungal activity against Candida albicans (MIC = 19 µg/mL). Biosynthetic experiments with stable isotope-labelled acetate allowed defining the elongation process in 1. For the first time the use of glycolate as a starter unit in the polyketide biosynthesis of amphidinol metabolites was unambiguously demonstrated.
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Transcriptome Analysis of Core Dinoflagellates Reveals a Universal Bias towards "GC" Rich Codons. Mar Drugs 2017; 15:md15050125. [PMID: 28448468 PMCID: PMC5450531 DOI: 10.3390/md15050125] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Revised: 04/11/2017] [Accepted: 04/20/2017] [Indexed: 11/24/2022] Open
Abstract
Although dinoflagellates are a potential source of pharmaceuticals and natural products, the mechanisms for regulating and producing these compounds are largely unknown because of extensive post-transcriptional control of gene expression. One well-documented mechanism for controlling gene expression during translation is codon bias, whereby specific codons slow or even terminate protein synthesis. Approximately 10,000 annotatable genes from fifteen “core” dinoflagellate transcriptomes along a range of overall guanine and cytosine (GC) content were used for codonW analysis to determine the relative synonymous codon usage (RSCU) and the GC content at each codon position. GC bias in the analyzed dataset and at the third codon position varied from 51% and 54% to 66% and 88%, respectively. Codons poor in GC were observed to be universally absent, but bias was most pronounced for codons ending in uracil followed by adenine (UA). GC bias at the third codon position was able to explain low abundance codons as well as the low effective number of codons. Thus, we propose that a bias towards codons rich in GC bases is a universal feature of core dinoflagellates, possibly relating to their unique chromosome structure, and not likely a major mechanism for controlling gene expression.
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