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Klemm K, Cembella A, Clarke D, Cusack C, Arneborg L, Karlson B, Liu Y, Naustvoll L, Siano R, Gran-Stadniczeñko S, John U. Apparent biogeographical trends in Alexandrium blooms for northern Europe: identifying links to climate change and effective adaptive actions. HARMFUL ALGAE 2022; 119:102335. [PMID: 36344194 DOI: 10.1016/j.hal.2022.102335] [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: 12/31/2021] [Revised: 09/15/2022] [Accepted: 10/15/2022] [Indexed: 06/16/2023]
Abstract
The marine dinoflagellate Alexandrium Halim represents perhaps the most significant and intensively studied genus with respect to species diversity, life history strategies, toxigenicity, biogeographical distribution, and global magnitude and consequences harmful algal blooms (HABs). The socioeconomic impacts, environmental and human health risks, and mitigation strategies for toxigenic Alexandrium blooms have also been explored in recent years. Human adaptive actions based on future scenarios of bloom dynamics and shifts in biogeographical distribution under climate-change parameters remain under development and not yet implemented on a regional scale. In the CoCliME (Co-development of climate services for adaptation to changing marine ecosystems) project these issues were addressed with respect to past, current and anticipated future status of key HAB genera and expected benefits of enhanced monitoring. Data on the distribution and frequency of Alexandrium blooms related to paralytic shellfish toxin (PST) events from key CoCliME Case Study areas, comprising the North Sea and adjacent Kattegat-Skagerrak, Norwegian Sea, and Baltic Sea, and eastern North Atlantic marginal seas, were evaluated in a contemporary and historical context over the past several decades. The first evidence of possible biogeographical expansion of Alexandrium taxa into eastern Arctic gateways was provided from DNA barcoding signatures. Various key climate change indicators, such as salinity, temperature, and water-column stratification, relevant to Alexandrium bloom initiation and development were identified. The possible influence of changing variables on bloom dynamics, magnitude, frequency and spatial and temporal distribution were interpreted in the context of regional ocean climate models. These climate change impact indicators may play key roles in selecting for the occurrence and diversity of Alexandrium species within the broader microeukaryote communities. For example, shifts to higher temperature and lower salinity regimes predicted for the southern North Sea indicate the potential for increased Alexandrium blooms, currently absent from this area. Ecological and socioeconomic impacts of Alexandrium blooms and effects on fisheries and aquaculture resources and coastal ecosystem function are evaluated, and, where feasible, effective adaptation strategies are proposed herein as emerging climate services.
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Affiliation(s)
- Kerstin Klemm
- Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, Bremerhaven 27570, Germany; Helmholtz Institute for Functional Marine Biodiversity at the University of Oldenburg (HIFMB), Ammerländer Heerstraße 231, Oldenburg 26129, Germany
| | - Allan Cembella
- Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, Bremerhaven 27570, Germany
| | - Dave Clarke
- Marine Institute, Rinville, Oranmore, Co. Galway, Ireland
| | | | - Lars Arneborg
- Swedish Meteorological and Hydrological Institute, Research and development, oceanography, Sven Källfelts gata 15, Västra Frölunda, SE-426 71, Sweden
| | - Bengt Karlson
- Swedish Meteorological and Hydrological Institute, Research and development, oceanography, Sven Källfelts gata 15, Västra Frölunda, SE-426 71, Sweden
| | - Ye Liu
- Swedish Meteorological and Hydrological Institute, Research and development, oceanography, Sven Källfelts gata 15, Västra Frölunda, SE-426 71, Sweden
| | - Lars Naustvoll
- Institute of Marine Research, PO Box 1870 Nordnes, Bergen NO-5817, Norway
| | | | - Sandra Gran-Stadniczeñko
- Section for Aquatic Biology and Toxicology, Department of Biosciences, University of Oslo, P.O. Box 1066, Blindern, Oslo 0316, Norway
| | - Uwe John
- Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, Bremerhaven 27570, Germany; Helmholtz Institute for Functional Marine Biodiversity at the University of Oldenburg (HIFMB), Ammerländer Heerstraße 231, Oldenburg 26129, Germany.
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Thi Nhu Bui Q, Kim H, Wang H, Ki JS. Unveiling the genomic structures and evolutionary events of the saxitoxin biosynthetic gene sxtA in the marine toxic dinoflagellate Alexandrium. Mol Phylogenet Evol 2022; 168:107417. [PMID: 35031458 DOI: 10.1016/j.ympev.2022.107417] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 11/24/2021] [Accepted: 12/27/2021] [Indexed: 12/30/2022]
Abstract
Marine dinoflagellates Alexandriumare known to produce saxitoxin (STX) and cause paralytic shellfish poisoning (PSP) which can result in mortality in human. SxtA is considered a core gene for the biosynthesis of STX. However, its gene coding structure and evolutionary history have yet to be fully elucidated. Here, we determined the full-length sequences of sxtA cDNA and genomic coding regions from two toxic dinoflagellates, Alexandrium catenella (LIMS-PS-2645 and LIMS-PS-2647) andA. pacificum (LMBE-C4), characterised their domain structures, and resolved evolutionary events. The sxtA gene was encoded on the genome without introns, and was identical in length (4002 bp) between two A. catenella strains, but their sequences differed from A. pacificum (5031 bp). SxtA consists of four domains, sxtA1, sxtA2, sxtA3, and sxtA4; however, A. pacificum has an extra domain TauD near sxtA1. Each domain had >64.4% GC content, with the highest being 71.6% in sxtA3. Molecular divergence was found to be significantly higher in sxtA4 than in the other domains. Phylogenetic trees of sxtA and separate domains showed that bacteria diverged earliest, followed by non-toxic, toxic cyanobacteria, toxic dinoflagellates. While sxtA domains in Alexandrium were similar to the PKS-like structure with the conserved sxtA1, sxtA2, and sxtA3. PKS_KS may be replaced by sxtA4 in toxic Alexandrium. These suggest that sxtA in Alexandrium may have evolved by acquiring specific domains, whose modification and complexity markedly affect toxin biosynthesis.
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Affiliation(s)
- Quynh Thi Nhu Bui
- Department of Biotechnology, Sangmyung University, Seoul 03016, South Korea
| | - Hansol Kim
- Department of Biotechnology, Sangmyung University, Seoul 03016, South Korea
| | - Hui Wang
- Department of Biotechnology, Sangmyung University, Seoul 03016, South Korea; Hunan Province Key Laboratory of Typical Environmental Pollution and Health Hazards, School of Public Health, University of South China, Hengyang 421001, China
| | - Jang-Seu Ki
- Department of Biotechnology, Sangmyung University, Seoul 03016, South Korea.
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Branco S, Oliveira MMM, Salgueiro F, Vilar MCP, Azevedo SMFO, Menezes M. Morphology and molecular phylogeny of a new PST-producing dinoflagellate species: Alexandrium fragae sp. nov. (Gonyaulacales, dinophyceae). HARMFUL ALGAE 2020; 95:101793. [PMID: 32439062 DOI: 10.1016/j.hal.2020.101793] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 02/27/2020] [Accepted: 03/01/2020] [Indexed: 06/11/2023]
Abstract
The genus Alexandrium comprises some of the most potentially toxic marine algae. A new toxic species of Alexandrium, A. fragae sp. nov., was found in Guanabara Bay, Rio de Janeiro, southern Brazil. The new species produces GTX2&3 and STX. The cell morphology of A. fragae resembles A. minutum in many characters, including the small size; the rounded-elliptical shape; and the shapes of the apical pore complex (APC), first apical plate (1'), sixth precingular plate (6″), and anterior and posterior sulcal plates (s.a. and s.p.). The main diagnostic characters of A. fragae are the ornamentation pattern, smooth epitheca and reticulated hypotheca, all of which were present in both natural populations and cultures. Phylogenies inferred from the ITS, LSU, and SSU rDNA of A. fragae showed that A. fragae clustered in a well-supported clade, distinct from other Alexandrium species. Morphology and molecular analyses based on ITS and LSU rDNA indicated that A. fragae strains and Alexandrium sp. from Japan (D163C5, D164C6) are a single species. Our findings suggest that the Alexandrium morphotype with a smooth epitheca and reticulated hypotheca, previously identified as A. minutum in different geographic regions, may corresponds to A. fragae.
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Affiliation(s)
- Suema Branco
- Laboratório de Ficologia, Departamento de Botânica, Museu Nacional / Universidade Federal do Rio de Janeiro, Quinta da Boa Vista, s/no, São Cristóvão, 20940-040 Rio de Janeiro, Brazil.
| | - Mair M M Oliveira
- Laboratório de Biomineralização, Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Cidade Universitária, 21941-590 Rio de Janeiro, Brazil
| | - Fabiano Salgueiro
- Laboratório de Biodiversidade e Evolução Molecular, Universidade Federal do Estado do Rio de Janeiro, Av. Pasteur 458, sala 512, Urca, 22290-240 Rio de Janeiro, Brazil
| | - Mauro C P Vilar
- Laboratório de Ecofisiologia e Toxicologia de Cianobactérias, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, 21949-902 Rio de Janeiro, Brazil
| | - Sandra M F O Azevedo
- Laboratório de Ecofisiologia e Toxicologia de Cianobactérias, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, 21949-902 Rio de Janeiro, Brazil
| | - Mariângela Menezes
- Laboratório de Ficologia, Departamento de Botânica, Museu Nacional / Universidade Federal do Rio de Janeiro, Quinta da Boa Vista, s/no, São Cristóvão, 20940-040 Rio de Janeiro, Brazil
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Murray SA, Ruvindy R, Kohli GS, Anderson DM, Brosnahan ML. Evaluation of sxtA and rDNA qPCR assays through monitoring of an inshore bloom of Alexandrium catenella Group 1. Sci Rep 2019; 9:14532. [PMID: 31601884 PMCID: PMC6787220 DOI: 10.1038/s41598-019-51074-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2019] [Accepted: 09/24/2019] [Indexed: 12/16/2022] Open
Abstract
Alexandrium catenella (formerly A. tamarense Group 1, or A. fundyense) is the leading cause of Paralytic Shellfish Poisoning in North and South America, Europe, Africa, Australia and Asia. The quantification of A.catenella via sxtA, a gene involved in Paralytic Shellfish Toxin synthesis, may be a promising approach, but has not been evaluated in situ on blooms of A. catenella, in which cell abundances may vary from not detectable to in the order of 106 cells L-1. In this study, we compared sxtA assay performance to a qPCR assay targeted to a species-specific region of ribosomal DNA (rDNA) and an established fluorescent in situ hybridization (FISH) microscopy method. Passing-Bablok regression analyses revealed the sxtA assay to overestimate abundances when <5 cell equivalents A. catenella DNA were analysed, but otherwise was closer to microscopy estimates than the rDNA assay, which overestimated abundance across the full range of concentrations analysed, indicative of a copy number difference between the bloom population and a culture used for assay calibration a priori. In contrast, the sxtA assay performed more consistently, indicating less copy number variation. The sxtA assay was generally reliable, fast and effective in quantifying A. catenella and was predictive of PST contamination of shellfish.
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Affiliation(s)
- Shauna A Murray
- Climate Change Cluster, University of Technology Sydney, Ultimo, NSW, 2007, Australia.
| | - Rendy Ruvindy
- Climate Change Cluster, University of Technology Sydney, Ultimo, NSW, 2007, Australia
| | - Gurjeet S Kohli
- Climate Change Cluster, University of Technology Sydney, Ultimo, NSW, 2007, Australia
- Ramaciotti Centre for Gene Function Analysis, University of New South Wales, Sydney, NSW, 2052, Australia
| | - Donald M Anderson
- Woods Hole Oceanographic Institution, MS # 32, 266 Woods Hole Road, Woods Hole, Massachusetts, 02543, United States
| | - Michael L Brosnahan
- Woods Hole Oceanographic Institution, MS # 32, 266 Woods Hole Road, Woods Hole, Massachusetts, 02543, United States
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Ruvindy R, Bolch CJ, MacKenzie L, Smith KF, Murray SA. qPCR Assays for the Detection and Quantification of Multiple Paralytic Shellfish Toxin-Producing Species of Alexandrium. Front Microbiol 2018; 9:3153. [PMID: 30619217 PMCID: PMC6305576 DOI: 10.3389/fmicb.2018.03153] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Accepted: 12/05/2018] [Indexed: 11/30/2022] Open
Abstract
Paralytic shellfish toxin producing dinoflagellates have negatively impacted the shellfish aquaculture industry worldwide, including in Australia and New Zealand. Morphologically identical cryptic species of dinoflagellates that may differ in toxicity, in particular, species of the former Alexandrium tamarense species complex, co-occur in Australia, as they do in multiple regions in Asia and Europe. To understand the dynamics and the ecological drivers of the growth of each species in the field, accurate quantification at the species level is crucial. We have developed the first quantitative polymerase chain reaction (qPCR) primers for A. australiense, and new primers targeting A. ostenfeldii, A. catenella, and A. pacificum. We showed that our new primers for A. pacificum are more specific than previously published primer pairs. These assays can be used to quantify planktonic cells and cysts in the water column and in sediment samples with limits of detection of 2 cells/L for the A. catenella and A. australiense assays, 2 cells/L and 1 cyst/mg sediment for the A. pacificum assay, and 1 cells/L for the A. ostenfeldii assay, and efficiencies of >90%. We utilized these assays to discriminate and quantify co-occurring A. catenella, A. pacificum, and A. australiense in samples from the east coast of Tasmania, Australia.
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Affiliation(s)
- Rendy Ruvindy
- Climate Change Cluster, University of Technology Sydney, Sydney, NSW, Australia
| | - Christopher J. Bolch
- Institute for Marine and Antarctic Studies, University of Tasmania, Launceston, TAS, Australia
| | | | | | - Shauna A. Murray
- Climate Change Cluster, University of Technology Sydney, Sydney, NSW, Australia
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Lewis AM, Coates LN, Turner AD, Percy L, Lewis J. A review of the global distribution of Alexandrium minutum (Dinophyceae) and comments on ecology and associated paralytic shellfish toxin profiles, with a focus on Northern Europe. JOURNAL OF PHYCOLOGY 2018; 54:581-598. [PMID: 30047623 DOI: 10.1111/jpy.12768] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Accepted: 06/21/2018] [Indexed: 06/08/2023]
Abstract
Alexandrium minutum is a globally distributed harmful algal bloom species with many strains that are known to produce paralytic shellfish toxins (PSTs) and consequently represent a concern to human and ecosystem health. This review highlights that A. minutum typically occurs in sheltered locations, with cell growth occurring during periods of stable water conditions. Sediment characteristics are important in the persistence of this species within a location, with fine sediments providing cyst deposits for ongoing inoculation to the water column. Toxic strains of A. minutum do not produce a consistent toxin profile, different populations produce a range of PSTs in differing quantities. Novel cluster analysis of published A. minutum toxin profiles indicates five PST profile clusters globally. Some clusters are grouped geographically (Northern Europe) while others are widely spread. Isolates from Taiwan have a range of toxin profile clusters and this area appears to have the most diverse set of PST producing A. minutum populations. These toxin profiles indicate that within the United Kingdom there are two populations of A. minutum grouping with strains from Northern France and Southern Ireland. There is a degree of interconnectivity in this region due to oceanic circulation and a high level of shipping and recreational boating. Further research into the interrelationships between the A. minutum populations in this global region would be of value.
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Affiliation(s)
- Adam Michael Lewis
- Cefas, The Nothe, Barrack Road, Weymouth, Dorset, DT48UB, UK
- Faculty of Science and Technology, The University of Westminster, 115 New Cavendish Street, London, W1W6UW, UK
| | | | - Andrew D Turner
- Cefas, The Nothe, Barrack Road, Weymouth, Dorset, DT48UB, UK
| | - Linda Percy
- Faculty of Science and Technology, The University of Westminster, 115 New Cavendish Street, London, W1W6UW, UK
| | - Jane Lewis
- Faculty of Science and Technology, The University of Westminster, 115 New Cavendish Street, London, W1W6UW, UK
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Kang HC, Jin Jeong H, So Jin K, You JH, Hee Ok J. Differential feeding by common heterotrophic protists on 12 different Alexandrium species. HARMFUL ALGAE 2018; 78:106-117. [PMID: 30196918 DOI: 10.1016/j.hal.2018.08.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 08/15/2018] [Accepted: 08/15/2018] [Indexed: 06/08/2023]
Abstract
The genus Alexandrium often forms harmful algal blooms causing human illness and large-scale mortality of fish and shellfish. Thus, Alexandrium bloom dynamics are primary concerns for scientists, government officials, aquaculture farmers, and the public. To understand bloom dynamics, mortality due to predation needs to be assessed; however, interactions between many Alexandrium species and their potential predators have not previously been reported. Thus, feeding by five common heterotrophic dinoflagellates (Oxyrrhis marina, Gyrodinium dominans, Polykrikos kofoidii, Pfiesteria piscicida, and Oblea rotunda) and a naked ciliate (Strombidinopsis sp.) on 12 Alexandrium species was examined. Furthermore, the growth and ingestion rates of P. kofoidii on A. minutum CCMP 1888 (previously A. lusitanicum), A. minutum CCMP 113, and A. tamarense were measured as a function of prey concentration. The growth rates of P. kofoidii on the other Alexandrium species at single high prey concentrations were measured, at which the growth rates on A. minutum CCMP 1888 and A. tamarense were saturated. Feeding occurrence by these predators on 12 Alexandrium species could be categorized into 6 different prey groups. Each Alexandrium species was consumed by at least one predator; however, there was no Alexandrium species that was eaten by all six predators. Cells of A. minutum CCMP 1888, A. minutum CCMP 113, and A. tamarense were fed upon by four predators, but A. affine and A. pacificum by only one predator species, P. kofoidii or Strombidinopsis sp. Furthermore, A. minutum CCMP 1888 and A. tamarense supported high growth rates of P. kofoidii, but the other Alexandrium species did not support, but rather inhibited P. kofoidii growth. With increasing prey concentrations, the growth and ingestion rates of P. kofoidii on A. minutum CCMP 1888 and A. tamarense increased and became saturated, whereas those on A. minutum CCMP 113 continuously decreased. The maximum growth rates of P. kofoidii on A. tamarense and A. minutum CCMP 1888 were 1.010 and 0.765 d-1, respectively, and P. kofoidii maximum ingestion rates were 26.2 and 11.1 ng C predator-1d-1, respectively. In contrast, the growth rates of P. kofoidii on the other Alexandrium species at single high prey concentrations were almost zero (A. pacificum) or negative. Based on the feeding occurrence and growth and ingestion rates of predators on 12 Alexandrium species, it is suggested that common heterotrophic protistan predators respond differently to different Alexandrium species, and thus ecological niches of the Alexandrium species may be different from each other. These results may provide an insight into the roles of protistan predators in bloom dynamics of Alexandrium species.
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Affiliation(s)
- Hee Chang Kang
- School of Earth and Environmental Sciences, College of Natural Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Hae Jin Jeong
- School of Earth and Environmental Sciences, College of Natural Sciences, Seoul National University, Seoul 08826, Republic of Korea; Advanced Institutes of Convergence Technology, Suwon, Gyeonggi-do, 16229, Republic of Korea.
| | - Kim So Jin
- School of Earth and Environmental Sciences, College of Natural Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Ji Hyun You
- School of Earth and Environmental Sciences, College of Natural Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Jin Hee Ok
- School of Earth and Environmental Sciences, College of Natural Sciences, Seoul National University, Seoul 08826, Republic of Korea
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Lim AS, Jeong HJ, Ok JH, Kim SJ. Feeding by the harmful phototrophic dinoflagellate Takayama tasmanica (Family Kareniaceae). HARMFUL ALGAE 2018; 74:19-29. [PMID: 29724340 DOI: 10.1016/j.hal.2018.03.009] [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: 01/05/2018] [Revised: 03/25/2018] [Accepted: 03/25/2018] [Indexed: 06/08/2023]
Abstract
The trophic mode of a phototrophic dinoflagellate is a critical factor in the dynamics of its harmful algal bloom. Recent discoveries of the mixotrophic capabilities of phototrophic dinoflagellates have changed the traditional view of bloom dynamics and prediction models. Here, mixotrophy in the harmful phototrophic dinoflagellate Takayama tasmanica was examined. Moreover, growth and ingestion rates of T. tasmanica on each of Alexandrium minutum CCMP1888 and Alexandrium tamarense CCMP1493, suitable prey, were determined as a function of prey concentration. This study reported for the first time that T. tasmanica is a mixotrophic species. Among the phytoplankton species offered as prey, T. tasmanica fed on all prey species whose equivalent spherical diameter (ESD) was greater than 30 μm, but also A. minutum whose ESD was 19 μm. In contrast, T. tasmanica did not feed on the phototrophic dinoflagellates Heterocapsa triquetra, Gymnodinium aureolum, Scrippsiella acuminata (previously S. trochoidea), Cochlodinium polykrikoides, Alexandrium affine, Alexandrium insuetum, and Alexandrium pacificum that its sister species Takayama helix is able to feed on. With increasing mean prey concentration, ingestion rates of T. tasmanica on A. minutum increased, but became saturated at the prey concentrations of >2130 cells mL-1 (1070 ng C mL-1). The maximum ingestion rate (MIR) of T. tasmanica on A. minutum was 0.5 ng C predator-1 d-1 (1.0 cells predator-1 d-1) which is only 64% of the body carbon of a T. tasmanica cell. Growth rates of T. tasmanica on A. minutum were not affected by prey concentrations. Thus, the low maximum ingestion rate is likely to be responsible for the small increases of its growth rate through mixotrophy. In addition, neither growth nor ingestion rates of T. tasmanica feeding on Alexandrium tamarense were affected by prey concentrations. The maximum ingestion rate of T. tasmanica on A. minutum was considerably lower than that of T. helix on the same prey species. Therefore, the mixotrophic ability of T. tasmanica is weaker than that of T. helix, and also T. tasmanica may have an ecological niche different from that of T. helix in marine ecosystems.
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Affiliation(s)
- An Suk Lim
- School of Earth and Environmental Sciences, College of Natural Sciences, Seoul National University, Seoul 08826, Republic of Korea; Brain Korea 21 Plus Program, School of Earth and Environmental Sciences, College of Natural Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Hae Jin Jeong
- School of Earth and Environmental Sciences, College of Natural Sciences, Seoul National University, Seoul 08826, Republic of Korea; Advanced Institutes of Convergence Technology, Suwon, Gyeonggi-do, 16229, Republic of Korea.
| | - Jin Hee Ok
- School of Earth and Environmental Sciences, College of Natural Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - So Jin Kim
- School of Earth and Environmental Sciences, College of Natural Sciences, Seoul National University, Seoul 08826, Republic of Korea
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Mello RV, Meccheri FS, Bagatini IL, Rodrigues-Filho E, Vieira AA. MALDI-TOF MS based discrimination of coccoid green microalgae (Selenastraceae, Chlorophyta). ALGAL RES 2017. [DOI: 10.1016/j.algal.2017.10.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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10
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Klouch KZ, Schmidt S, Andrieux-Loyer F, Le Gac M, Hervio-Heath D, Qui-Minet ZN, Quéré J, Bigeard E, Guillou L, Siano R. Historical records from dated sediment cores reveal the multidecadal dynamic of the toxic dinoflagellateAlexandrium minutumin the Bay of Brest (France). FEMS Microbiol Ecol 2016; 92:fiw101. [DOI: 10.1093/femsec/fiw101] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/04/2016] [Indexed: 01/01/2023] Open
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Vanormelingen P, Evans KM, Mann DG, Lance S, Debeer AE, D'Hondt S, Verstraete T, De Meester L, Vyverman W. Genotypic diversity and differentiation among populations of two benthic freshwater diatoms as revealed by microsatellites. Mol Ecol 2015; 24:4433-48. [DOI: 10.1111/mec.13336] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Revised: 07/21/2015] [Accepted: 07/22/2015] [Indexed: 12/30/2022]
Affiliation(s)
- Pieter Vanormelingen
- Laboratory of Protistology and Aquatic Ecology; Ghent University; Krijgslaan 281 - S8 Gent 9000 Belgium
| | - Katharine M. Evans
- School of Geosciences; University of Edinburgh; Edinburgh EH9 3JW UK
- Royal Botanic Garden; Edinburgh EH3 5LR UK
| | - David G. Mann
- Royal Botanic Garden; Edinburgh EH3 5LR UK
- Aquatic Ecosystems; Institute for Food and Agricultural Research and Technology (IRTA); Crta de Poble Nou Km 5.5 E-43540 Sant Carles de la Ràpita Catalunya Spain
| | - Stacey Lance
- Savannah River Ecology Laboratory; University of Georgia; Aiken SC USA
| | - Ann-Eline Debeer
- Laboratory of Protistology and Aquatic Ecology; Ghent University; Krijgslaan 281 - S8 Gent 9000 Belgium
| | - Sofie D'Hondt
- Laboratory of Protistology and Aquatic Ecology; Ghent University; Krijgslaan 281 - S8 Gent 9000 Belgium
| | - Tine Verstraete
- Laboratory of Protistology and Aquatic Ecology; Ghent University; Krijgslaan 281 - S8 Gent 9000 Belgium
| | - Luc De Meester
- Laboratory of Aquatic Ecology, Evolution and Conservation; Katholieke Universiteit Leuven; Ch. De Bériotstraat 32 Leuven 3000 Belgium
| | - Wim Vyverman
- Laboratory of Protistology and Aquatic Ecology; Ghent University; Krijgslaan 281 - S8 Gent 9000 Belgium
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Stüken A, Riobó P, Franco J, Jakobsen KS, Guillou L, Figueroa RI. Paralytic shellfish toxin content is related to genomic sxtA4 copy number in Alexandrium minutum strains. Front Microbiol 2015; 6:404. [PMID: 25983733 PMCID: PMC4416454 DOI: 10.3389/fmicb.2015.00404] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Accepted: 04/17/2015] [Indexed: 11/27/2022] Open
Abstract
Dinoflagellates are microscopic aquatic eukaryotes with huge genomes and an unusual cell regulation. For example, most genes are present in numerous copies and all copies seem to be obligatorily transcribed. The consequence of the gene copy number (CPN) for final protein synthesis is, however, not clear. One such gene is sxtA, the starting gene of paralytic shellfish toxin (PST) synthesis. PSTs are small neurotoxic compounds that can accumulate in the food chain and cause serious poisoning incidences when ingested. They are produced by dinoflagellates of the genera Alexandrium, Gymnodium, and Pyrodinium. Here we investigated if the genomic CPN of sxtA4 is related to PST content in Alexandrium minutum cells. SxtA4 is the 4th domain of the sxtA gene and its presence is essential for PST synthesis in dinoflagellates. We used PST and genome size measurements as well as quantitative PCR to analyze sxtA4 CPN and toxin content in 15 A. minutum strains. Our results show a strong positive correlation between the sxtA4 CPN and the total amount of PST produced in actively growing A. minutum cells. This correlation was independent of the toxin profile produced, as long as the strain contained the genomic domains sxtA1 and sxtA4.
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Affiliation(s)
- Anke Stüken
- Department of Biosciences, University of Oslo Oslo, Norway
| | - Pilar Riobó
- U.A. Microalgas Nocivas (Consejo Superior de Investigaciones Científicas - Instituto Español de Oceanografía), Instituto de Investigaciones Marinas Vigo, Spain
| | - José Franco
- U.A. Microalgas Nocivas (Consejo Superior de Investigaciones Científicas - Instituto Español de Oceanografía), Instituto de Investigaciones Marinas Vigo, Spain
| | - Kjetill S Jakobsen
- Centre for Ecological and Evolutionary Synthesis, Department of Biosciences, University of Oslo Oslo, Norway
| | - Laure Guillou
- Laboratoire Adaptation et Diversité en Milieu Marin, CNRS, UMR 7144 Roscoff, France ; Sorbonne Universités - Université Pierre et Marie Curie, UMR 7144 Roscoff, France
| | - Rosa I Figueroa
- Aquatic Ecology, Lund University Lund, Sweden ; U.A. Microalgas Nocivas (Consejo Superior de Investigaciones Científicas - Instituto Español de Oceanografía), Instituto Español de Oceanografía Vigo, Spain
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Zou C, Ye RM, Zheng JW, Luo ZH, Gu HF, Yang WD, Li HY, Liu JS. Molecular phylogeny and PSP toxin profile of the Alexandrium tamarense species complex along the coast of China. MARINE POLLUTION BULLETIN 2014; 89:209-219. [PMID: 25444620 DOI: 10.1016/j.marpolbul.2014.09.056] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2014] [Revised: 09/26/2014] [Accepted: 09/29/2014] [Indexed: 06/04/2023]
Abstract
To explore the genetic diversity and paralytic shellfish poisoning (PSP) toxin profile of the Alexandrium tamarense species complex along the coast of China, 67 strains of A. tamarense from the China Sea were collected and genetic diversity were analyzed based on the rDNA sequences. In addition, PSP toxin compositions and contents were detected by HPLC. According to the 5.8S rDNA and ITS, and LSU rDNA D1-D2 sequence, A. tamarense in the China Sea comprises at least Group IV and Group I ribotypes. In these Chinese strains, the toxins with the highest concentration in the profile were C1/2, gonyautoxins 1/4 (GTX1/4) and neosaxitoxin (NEO). However, the toxin profiles were atypical and C1/2 toxins were not detected in some strains. No strict correlation was observed between the PSP toxins profile and the geographical distribution.
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Affiliation(s)
- Cheng Zou
- College of Life Science and Technology, Jinan University, Guangzhou 510632, China; Key Laboratory of Aquatic Eutrophication and Control of Harmful Algal Blooms of Guangdong Higher Education Institute, Guangzhou 510632, China
| | - Rui-Min Ye
- College of Life Science and Technology, Jinan University, Guangzhou 510632, China; Key Laboratory of Aquatic Eutrophication and Control of Harmful Algal Blooms of Guangdong Higher Education Institute, Guangzhou 510632, China
| | - Jian-Wei Zheng
- College of Life Science and Technology, Jinan University, Guangzhou 510632, China; Key Laboratory of Aquatic Eutrophication and Control of Harmful Algal Blooms of Guangdong Higher Education Institute, Guangzhou 510632, China
| | - Zhao-He Luo
- College of Life Science and Technology, Jinan University, Guangzhou 510632, China; The Third Institute of Oceanography, State Oceanic Administration, Xiamen 361005, China
| | - Hai-Feng Gu
- The Third Institute of Oceanography, State Oceanic Administration, Xiamen 361005, China
| | - Wei-Dong Yang
- College of Life Science and Technology, Jinan University, Guangzhou 510632, China; Key Laboratory of Aquatic Eutrophication and Control of Harmful Algal Blooms of Guangdong Higher Education Institute, Guangzhou 510632, China.
| | - Hong-Ye Li
- College of Life Science and Technology, Jinan University, Guangzhou 510632, China; Key Laboratory of Aquatic Eutrophication and Control of Harmful Algal Blooms of Guangdong Higher Education Institute, Guangzhou 510632, China
| | - Jie-Sheng Liu
- College of Life Science and Technology, Jinan University, Guangzhou 510632, China; Key Laboratory of Aquatic Eutrophication and Control of Harmful Algal Blooms of Guangdong Higher Education Institute, Guangzhou 510632, China
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Santos M, Costa PR, Porteiro FM, Moita MT. First report of a massive bloom of Alexandrium minutum (Dinophyceae) in middle North Atlantic: A coastal lagoon in S. Jorge Island, Azores. Toxicon 2014; 90:265-8. [DOI: 10.1016/j.toxicon.2014.08.065] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Revised: 08/14/2014] [Accepted: 08/18/2014] [Indexed: 10/24/2022]
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15
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Kremp A, Tahvanainen P, Litaker W, Krock B, Suikkanen S, Leaw CP, Tomas C. Phylogenetic relationships, morphological variation, and toxin patterns in the Alexandrium ostenfeldii (Dinophyceae) complex: implications for species boundaries and identities. JOURNAL OF PHYCOLOGY 2014; 50:81-100. [PMID: 26988010 DOI: 10.1111/jpy.12134] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2013] [Accepted: 09/03/2013] [Indexed: 05/16/2023]
Abstract
Alexandrium ostenfeldii (Paulsen) Balech and Tangen and A. peruvianum (Balech and B.R. Mendiola) Balech and Tangen are morphologically closely related dinoflagellates known to produce potent neurotoxins. Together with Gonyaulax dimorpha Biecheler, they constitute the A. ostenfeldii species complex. Due to the subtle differences in the morphological characters used to differentiate these species, unambiguous species identification has proven problematic. To better understand the species boundaries within the A. ostenfeldii complex we compared rDNA data, morphometric characters and toxin profiles of multiple cultured isolates from different geographic regions. Phylogenetic analysis of rDNA sequences from cultures characterized as A. ostenfeldii or A. peruvianum formed a monophyletic clade consisting of six distinct groups. Each group examined contained strains morphologically identified as either A. ostenfeldii or A. peruvianum. Though key morphological characters were generally found to be highly variable and not consistently distributed, selected plate features and toxin profiles differed significantly among phylogenetic clusters. Additional sequence analyses revealed a lack of compensatory base changes in ITS2 rRNA structure, low to intermediate ITS/5.8S uncorrected genetic distances, and evidence of reticulation. Together these data (criteria currently used for species delineation in dinoflagellates) imply that the A. ostenfeldii complex should be regarded a single genetically structured species until more material and alternative criteria for species delimitation are available. Consequently, we propose that A. peruvianum is a heterotypic synonym of A. ostenfeldii and this taxon name should be discontinued.
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Affiliation(s)
- Anke Kremp
- Finnish Environment Institute, Marine Research Centre, Erik Palménin aukio 1, Helsinki, 00560, Finland
| | - Pia Tahvanainen
- Finnish Environment Institute, Marine Research Centre, Erik Palménin aukio 1, Helsinki, 00560, Finland
- University of Helsinki, Tvärminne Zoological Station, J.A. Palménin tie 260, Hanko, 10900, Finland
| | - Wayne Litaker
- National Oceanic and Atmospheric Administration, National Ocean Service, Center for Coastal Fisheries and Habitat Research, 101 Pivers Island Rd., Beaufort, North Carolina
| | - Bernd Krock
- Alfred Wegener Institute for Polar and Marine Research, Division of Biosciences, Am Handelshafen 12, Bremerhaven, 27570, Germany
| | - Sanna Suikkanen
- Finnish Environment Institute, Marine Research Centre, Erik Palménin aukio 1, Helsinki, 00560, Finland
| | - Chui Pin Leaw
- Institute of Biodiversity and Environmental Conservation, University Malaysia Sarawak, Kota Samarahan, Sarawak, 94300, Malaysia
| | - Carmelo Tomas
- University of North Carolina at Wilmington, Center for Marine Science, Myrtle Grove 2336, Wilmington, North Carolina
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Dia A, Guillou L, Mauger S, Bigeard E, Marie D, Valero M, Destombe C. Spatiotemporal changes in the genetic diversity of harmful algal blooms caused by the toxic dinoflagellateAlexandrium minutum. Mol Ecol 2014; 23:549-60. [DOI: 10.1111/mec.12617] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2013] [Revised: 11/08/2013] [Accepted: 11/19/2013] [Indexed: 11/28/2022]
Affiliation(s)
- A. Dia
- Sorbonne Universités; UPMC Univ Paris 06; UMR 7144; Adaptation et diversité en milieu marin; Station Biologique de Roscoff; Place Georges Teissier CS 90074 29688 Roscoff France
- CNRS; UMR 7144; Adaptation et diversité en milieu marin; Station Biologique de Roscoff; Place Georges Teissier CS 90074 29688 Roscoff France
| | - L. Guillou
- Sorbonne Universités; UPMC Univ Paris 06; UMR 7144; Adaptation et diversité en milieu marin; Station Biologique de Roscoff; Place Georges Teissier CS 90074 29688 Roscoff France
- CNRS; UMR 7144; Adaptation et diversité en milieu marin; Station Biologique de Roscoff; Place Georges Teissier CS 90074 29688 Roscoff France
| | - S. Mauger
- Sorbonne Universités; UPMC Univ Paris 06; UMR 7144; Adaptation et diversité en milieu marin; Station Biologique de Roscoff; Place Georges Teissier CS 90074 29688 Roscoff France
- CNRS; UMR 7144; Adaptation et diversité en milieu marin; Station Biologique de Roscoff; Place Georges Teissier CS 90074 29688 Roscoff France
| | - E. Bigeard
- Sorbonne Universités; UPMC Univ Paris 06; UMR 7144; Adaptation et diversité en milieu marin; Station Biologique de Roscoff; Place Georges Teissier CS 90074 29688 Roscoff France
- CNRS; UMR 7144; Adaptation et diversité en milieu marin; Station Biologique de Roscoff; Place Georges Teissier CS 90074 29688 Roscoff France
| | - D. Marie
- Sorbonne Universités; UPMC Univ Paris 06; UMR 7144; Adaptation et diversité en milieu marin; Station Biologique de Roscoff; Place Georges Teissier CS 90074 29688 Roscoff France
- CNRS; UMR 7144; Adaptation et diversité en milieu marin; Station Biologique de Roscoff; Place Georges Teissier CS 90074 29688 Roscoff France
| | - M. Valero
- Sorbonne Universités; UPMC Univ Paris 06; UMR 7144; Adaptation et diversité en milieu marin; Station Biologique de Roscoff; Place Georges Teissier CS 90074 29688 Roscoff France
- CNRS; UMR 7144; Adaptation et diversité en milieu marin; Station Biologique de Roscoff; Place Georges Teissier CS 90074 29688 Roscoff France
| | - C. Destombe
- Sorbonne Universités; UPMC Univ Paris 06; UMR 7144; Adaptation et diversité en milieu marin; Station Biologique de Roscoff; Place Georges Teissier CS 90074 29688 Roscoff France
- CNRS; UMR 7144; Adaptation et diversité en milieu marin; Station Biologique de Roscoff; Place Georges Teissier CS 90074 29688 Roscoff France
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Collins S, Rost B, Rynearson TA. Evolutionary potential of marine phytoplankton under ocean acidification. Evol Appl 2013; 7:140-55. [PMID: 24454553 PMCID: PMC3894903 DOI: 10.1111/eva.12120] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2013] [Accepted: 09/12/2013] [Indexed: 01/22/2023] Open
Abstract
Marine phytoplankton have many obvious characters, such as rapid cell division rates and large population sizes, that give them the capacity to evolve in response to global change on timescales of weeks, months or decades. However, few studies directly investigate if this adaptive potential is likely to be realized. Because of this, evidence of to whether and how marine phytoplankton may evolve in response to global change is sparse. Here, we review studies that help predict evolutionary responses to global change in marine phytoplankton. We find limited support from experimental evolution that some taxa of marine phytoplankton may adapt to ocean acidification, and strong indications from studies of variation and structure in natural populations that selection on standing genetic variation is likely. Furthermore, we highlight the large body of literature on plastic responses to ocean acidification available, and evolutionary theory that may be used to link plastic and evolutionary responses. Because of the taxonomic breadth spanned by marine phytoplankton, and the diversity of roles they fill in ocean ecosystems and biogeochemical cycles, we stress the necessity of treating taxa or functional groups individually.
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Affiliation(s)
- Sinéad Collins
- Ashworth Laboratories, Institute of Evolutionary Biology, School of Biological Sciences, University of Edinburgh Edinburgh, UK
| | - Björn Rost
- Alfred Wegener Institute for Polar and Marine Research Bremerhaven, Germany
| | - Tatiana A Rynearson
- Graduate School of Oceanography, University of Rhode Island Narragansett, RI, USA
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18
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Peijnenburg KTCA, Goetze E. High evolutionary potential of marine zooplankton. Ecol Evol 2013; 3:2765-81. [PMID: 24567838 PMCID: PMC3930040 DOI: 10.1002/ece3.644] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2013] [Revised: 04/30/2013] [Accepted: 05/06/2013] [Indexed: 11/17/2022] Open
Abstract
Open ocean zooplankton often have been viewed as slowly evolving species that have limited capacity to respond adaptively to changing ocean conditions. Hence, attention has focused on the ecological responses of zooplankton to current global change, including range shifts and changing phenology. Here, we argue that zooplankton also are well poised for evolutionary responses to global change. We present theoretical arguments that suggest plankton species may respond rapidly to selection on mildly beneficial mutations due to exceptionally large population size, and consider the circumstantial evidence that supports our inference that selection may be particularly important for these species. We also review all primary population genetic studies of open ocean zooplankton and show that genetic isolation can be achieved at the scale of gyre systems in open ocean habitats (100s to 1000s of km). Furthermore, population genetic structure often varies across planktonic taxa, and appears to be linked to the particular ecological requirements of the organism. In combination, these characteristics should facilitate adaptive evolution to distinct oceanographic habitats in the plankton. We conclude that marine zooplankton may be capable of rapid evolutionary as well as ecological responses to changing ocean conditions, and discuss the implications of this view. We further suggest two priority areas for future research to test our hypothesis of high evolutionary potential in open ocean zooplankton, which will require (1) assessing how pervasive selection is in driving population divergence and (2) rigorously quantifying the spatial and temporal scales of population differentiation in the open ocean. Recent attention has focused on the ecological responses of open ocean zooplankton to current global change, including range shifts and changing phenology. Here, we argue that marine zooplankton also are well poised for evolutionary responses to global change.
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Affiliation(s)
- Katja T C A Peijnenburg
- Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam P.O. Box 94248, 1090 GE, Amsterdam, The Netherlands ; Department Marine Zoology, Naturalis Biodiversity Center P.O. Box 9517, 2300 RA, Leiden, The Netherlands
| | - Erica Goetze
- Department of Oceanography School of Ocean and Earth Science and Technology, University of Hawaii at Manoa Honolulu, Hawaii, 96822
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Richlen ML, Erdner DL, McCauley LAR, Libera K, Anderson DM. Extensive genetic diversity and rapid population differentiation during blooms of Alexandrium fundyense (Dinophyceae) in an isolated salt pond on Cape Cod, MA, USA. Ecol Evol 2012; 2:2588-99. [PMID: 23145343 PMCID: PMC3492784 DOI: 10.1002/ece3.373] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2012] [Revised: 07/22/2012] [Accepted: 07/26/2012] [Indexed: 11/24/2022] Open
Abstract
In Massachusetts, paralytic shellfish poisoning (PSP) is annually recurrent along the coastline, including within several small embayments on Cape Cod. One such system, the Nauset Marsh System (NMS), supports extensive marshes and a thriving shellfishing industry. Over the last decade, PSP in the NMS has grown significantly worse; however, the origins and dynamics of the toxic Alexandrium fundyense (Balech) populations that bloom within the NMS are not well known. This study examined a collection of 412 strains isolated from the NMS and the Gulf of Maine (GOM) in 2006-2007 to investigate the genetic characteristics of localized blooms and assess connectivity with coastal populations. Comparisons of genetic differentiation showed that A. fundyense blooms in the NMS exhibited extensive clonal diversity and were genetically distinct from populations in the GOM. In both project years, genetic differentiation was observed among temporal samples collected from the NMS, sometimes occurring on the order of approximately 7 days. The underlying reasons for temporal differentiation are unknown, but may be due, in part, to life-cycle characteristics unique to the populations in shallow embayments, or possibly driven by selection from parasitism and zooplankton grazing; these results highlight the need to investigate the role of selective forces in the genetic dynamics of bloom populations. The small geographic scale and limited connectivity of NMS salt ponds provide a novel system for investigating regulators of blooms, as well as the influence of selective forces on population structure, all of which are otherwise difficult or impossible to study in the adjacent open-coastal waters or within larger estuaries.
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Affiliation(s)
- Mindy L Richlen
- Woods Hole Oceanographic Institution Woods Hole, Massachusetts, 02543
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20
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Detection and quantification of cultured marine Alexandrium species by real-time PCR. World J Microbiol Biotechnol 2012; 28:3255-60. [PMID: 22864601 DOI: 10.1007/s11274-012-1136-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2012] [Accepted: 07/14/2012] [Indexed: 10/28/2022]
Abstract
The occurrence of harmful algal blooms (HABs) throughout the world has increased and poses a large threat to human health, fishery resources and tourism industries. The genus Alexandrium includes a number of toxic species associated with HABs. Therefore, it is very important to rapidly detect and monitor the harmful algae, such as Alexandrium genus. In this study, a standard curve of plasmid containing 18S rDNA-28S rDNA region from Alexandrium catenella was constructed and 5.8S rDNA sequence served as the primer of the real-time PCR. Cultured A. catenella, Alexandrium affine, Alexandrium lusitanicum and Alexandrium minutum samples were analyzed by real-time PCR using the same set of primers simultaneously. Using microscopy cells counts, 5.8S rDNA copies per cell and total DNA per cell were estimated. This assay method is promising for rapid detection of large number of Alexandrium samples.
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21
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Anderson DM, Alpermann TJ, Cembella AD, Collos Y, Masseret E, Montresor M. The globally distributed genus Alexandrium: multifaceted roles in marine ecosystems and impacts on human health. HARMFUL ALGAE 2012; 14:10-35. [PMID: 22308102 PMCID: PMC3269821 DOI: 10.1016/j.hal.2011.10.012] [Citation(s) in RCA: 369] [Impact Index Per Article: 30.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
The dinoflagellate genus Alexandrium is one of the major harmful algal bloom (HAB) genera with respect to the diversity, magnitude and consequences of blooms. The ability of Alexandrium to colonize multiple habitats and to persist over large regions through time is testimony to the adaptability and resilience of this group of species. Three different families of toxins, as well as an as yet incompletely characterized suite of allelochemicals are produced among Alexandrium species. Nutritional strategies are equally diverse, including the ability to utilize a range of inorganic and organic nutrient sources, and feeding by ingestion of other organisms. Many Alexandrium species have complex life histories that include sexuality and often, but not always, cyst formation, which is characteristic of a meroplanktonic life strategy and offers considerable ecological advantages. Due to the public health and ecosystem impacts of Alexandrium blooms, the genus has been extensively studied, and there exists a broad knowledge base that ranges from taxonomy and phylogeny through genomics and toxin biosynthesis to bloom dynamics and modeling. Here we present a review of the genus Alexandrium, focusing on the major toxic and otherwise harmful species.
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Affiliation(s)
- Donald M Anderson
- Woods Hole Oceanographic Institution, MS # 32, 266 Woods Hole Road, Woods Hole MA 02543; 508 289 2351
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Casabianca S, Penna A, Pecchioli E, Jordi A, Basterretxea G, Vernesi C. Population genetic structure and connectivity of the harmful dinoflagellate Alexandrium minutum in the Mediterranean Sea. Proc Biol Sci 2011; 279:129-38. [PMID: 21593032 DOI: 10.1098/rspb.2011.0708] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The toxin-producing microbial species Alexandrium minutum has a wide distribution in the Mediterranean Sea and causes high biomass blooms with consequences on the environment, human health and coastal-related economic activities. Comprehension of algal genetic differences and associated connectivity is fundamental to understand the geographical scale of adaptation and dispersal pathways of harmful microalgal species. In the present study, we combine A. minutum population genetic analyses based on microsatellites with indirect connectivity (C(i)) estimations derived from a general circulation model of the Mediterranean sea. Our results show that four major clusters of genetically homogeneous groups can be identified, loosely corresponding to four regional seas: Adriatic, Ionian, Tyrrhenian and Catalan. Each of the four clusters included a small fraction of mixed and allochthonous genotypes from other Mediterranean areas, but the assignment to one of the four clusters was sufficiently robust as proved by the high ancestry coefficient values displayed by most of the individuals (>84%). The population structure of A. minutum on this scale can be explained by microalgal dispersion following the main regional circulation patterns over successive generations. We hypothesize that limited connectivity among the A. minutum populations results in low gene flow but not in the erosion of variability within the population, as indicated by the high gene diversity values. This study represents a first and new integrated approach, combining both genetic and numerical methods, to characterize and interpret the population structure of a toxic microalgal species. This approach of characterizing genetic population structure and connectivity at a regional scale holds promise for the control and management of the harmful algal bloom events in the Mediterranean Sea.
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Affiliation(s)
- Silvia Casabianca
- Department of Biomolecular Sciences, University of Urbino, Pesaro 61121, Italy
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23
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Lowe CD, Montagnes DJS, Martin LE, Watts PC. High genetic diversity and fine-scale spatial structure in the marine flagellate Oxyrrhis marina (Dinophyceae) uncovered by microsatellite loci. PLoS One 2010; 5:e15557. [PMID: 21203414 PMCID: PMC3009739 DOI: 10.1371/journal.pone.0015557] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2010] [Accepted: 11/12/2010] [Indexed: 11/18/2022] Open
Abstract
Free-living marine protists are often assumed to be broadly distributed and genetically homogeneous on large spatial scales. However, an increasing application of highly polymorphic genetic markers (e.g., microsatellites) has provided evidence for high genetic diversity and population structuring on small spatial scales in many free-living protists. Here we characterise a panel of new microsatellite markers for the common marine flagellate Oxyrrhis marina. Nine microsatellite loci were used to assess genotypic diversity at two spatial scales by genotyping 200 isolates of O. marina from 6 broad geographic regions around Great Britain and Ireland; in one region, a single 2 km shore line was sampled intensively to assess fine-scale genetic diversity. Microsatellite loci resolved between 1-6 and 7-23 distinct alleles per region in the least and most variable loci respectively, with corresponding variation in expected heterozygosities (H(e)) of 0.00-0.30 and 0.81-0.93. Across the dataset, genotypic diversity was high with 183 genotypes detected from 200 isolates. Bayesian analysis of population structure supported two model populations. One population was distributed across all sampled regions; the other was confined to the intensively sampled shore, and thus two distinct populations co-occurred at this site. Whilst model-based analysis inferred a single UK-wide population, pairwise regional F(ST) values indicated weak to moderate population sub-division (0.01-0.12), but no clear correlation between spatial and genetic distance was evident. Data presented in this study highlight extensive genetic diversity for O. marina; however, it remains a substantial challenge to uncover the mechanisms that drive genetic diversity in free-living microorganisms.
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Affiliation(s)
- Chris D Lowe
- School of Biological Sciences, University of Liverpool, Liverpool, United Kingdom.
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Abstract
The role of geographic isolation in marine microbial speciation is hotly debated because of the high dispersal potential and large population sizes of planktonic microorganisms and the apparent lack of strong dispersal barriers in the open sea. Here, we show that gene flow between distant populations of the globally distributed, bloom-forming diatom species Pseudo-nitzschia pungens (clade I) is limited and follows a strong isolation by distance pattern. Furthermore, phylogenetic analysis implies that under appropriate geographic and environmental circumstances, like the pronounced climatic changes in the Pleistocene, population structuring may lead to speciation and hence may play an important role in diversification of marine planktonic microorganisms. A better understanding of the factors that control population structuring is thus essential to reveal the role of allopatric speciation in marine microorganisms.
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