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Shang L, Hu Z, Deng Y, Li J, Liu Y, Song X, Zhai X, Zhan Z, Tian W, Xu J, Han Y, Shen H, Ding H, Tang YZ. Transoceanic ships as a source of alien dinoflagellate invasions of inland freshwater ecosystems. HARMFUL ALGAE 2024; 135:102630. [PMID: 38830708 DOI: 10.1016/j.hal.2024.102630] [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: 12/11/2023] [Revised: 04/17/2024] [Accepted: 04/18/2024] [Indexed: 06/05/2024]
Abstract
Ships' ballast water and sediments have long been linked to the global transport and expansion of invasive species and thus have become a hot research topic and administrative challenge in the past decades. The relevant concerns, however, have been mainly about the ocean-to-ocean invasion and sampling practices have been almost exclusively conducted onboard. We examined and compared the dinoflagellate cysts assemblages in 49 sediment samples collected from ballast tanks of international and domestic routes ships, washing basins associated with a ship-repair yard, Jiangyin Port (PS), and the nearby area of Yangtze River (YR) during 2017-2018. A total of 43 dinoflagellates were fully identified to species level by metabarcoding, single-cyst PCR-based sequencing, cyst germination and phylogenetic analyses, including 12 species never reported from waters of China, 14 HABs-causing, 9 toxic, and 10 not strictly marine species. Our metabarcoding and single-cyst sequencing also detected many OTUs and cysts of dinoflagellates that could not be fully identified, indicating ballast tank sediments being a risky repository of currently unrecognizable invasive species. Particularly important, 10 brackish and fresh water species of dinoflagellate cysts (such as Tyrannodinium edax) were detected from the transoceanic ships, indicating these species may function as alien species potentially invading the inland rivers and adjacent lakes if these ships conduct deballast and other practices in fresh waterbodies. Significantly higher numbers of reads and OTUs of dinoflagellates in the ballast tanks and washing basins than that in PS and YR indicate a risk of releasing cysts by ships and the associated ship-repair yards to the surrounding waters. Phylogenetic analyses revealed high intra-species genetic diversity for multiple cyst species from different ballast tanks. Our work provides novel insights into the risk of bio-invasion to fresh waters conveyed in ship's ballast tank sediments and washing basins of shipyards.
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Affiliation(s)
- Lixia Shang
- 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 Marine Science and Technology Center, Qingdao 266237, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, 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 Marine Science and Technology Center, Qingdao 266237, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China
| | - Yunyan Deng
- 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 Marine Science and Technology Center, Qingdao 266237, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China
| | - Jing Li
- State Key Laboratory of Ballast Water Research, Comprehensive Technical Service Center of Jiangyin Customs, Jiangyin 214431, China
| | - Yuyang Liu
- 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 Marine Science and Technology Center, 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
| | - Xinyu Zhai
- 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
| | - Zifeng Zhan
- Laboratory of Marine Organism Taxonomy and Phylogeny, Qingdao Key Laboratory of Marine Biodiversity and Conservation, Shandong Province Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China
| | - Wen Tian
- State Key Laboratory of Ballast Water Research, Comprehensive Technical Service Center of Jiangyin Customs, Jiangyin 214431, China
| | - Jinxiang Xu
- State Key Laboratory of Ballast Water Research, Comprehensive Technical Service Center of Jiangyin Customs, Jiangyin 214431, China
| | - Yangchun Han
- State Key Laboratory of Ballast Water Research, Comprehensive Technical Service Center of Jiangyin Customs, Jiangyin 214431, China
| | - Hao Shen
- State Key Laboratory of Ballast Water Research, Comprehensive Technical Service Center of Jiangyin Customs, Jiangyin 214431, China
| | - Hua Ding
- State Key Laboratory of Ballast Water Research, Comprehensive Technical Service Center of Jiangyin Customs, Jiangyin 214431, 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 Marine Science and Technology Center, Qingdao 266237, China; Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao 266071, China.
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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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Jerney J, Rengefors K, Nagai S, Krock B, Sjöqvist C, Suikkanen S, Kremp A. Seasonal genotype dynamics of a marine dinoflagellate: Pelagic populations are homogeneous and as diverse as benthic seed banks. Mol Ecol 2022; 31:512-528. [PMID: 34716943 PMCID: PMC9298838 DOI: 10.1111/mec.16257] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 10/19/2021] [Accepted: 10/25/2021] [Indexed: 11/27/2022]
Abstract
Genetic diversity is the basis for evolutionary adaptation and selection under changing environmental conditions. Phytoplankton populations are genotypically diverse, can become genetically differentiated within small spatiotemporal scales and many species form resting stages. Resting stage accumulations in sediments (seed banks) are expected to serve as reservoirs for genetic information, but so far their role in maintaining phytoplankton diversity and in evolution has remained unclear. In this study we used the toxic dinoflagellate Alexandrium ostenfeldii (Dinophyceae) as a model organism to investigate if (i) the benthic seed bank is more diverse than the pelagic population and (ii) the pelagic population is seasonally differentiated. Resting stages (benthic) and plankton (pelagic) samples were collected at a coastal bloom site in the Baltic Sea, followed by cell isolation and genotyping using microsatellite markers (MS) and restriction site associated DNA sequencing (RAD). High clonal diversity (98%-100%) combined with intermediate to low gene diversity (0.58-0.03, depending on the marker) was found. Surprisingly, the benthic and pelagic fractions of the population were equally diverse, and the pelagic fraction was temporally homogeneous, despite seasonal fluctuation of environmental selection pressures. The results of this study suggest that continuous benthic-pelagic coupling, combined with frequent sexual reproduction, as indicated by persistent linkage equilibrium, prevent the dominance of single clonal lineages in a dynamic environment. Both processes harmonize the pelagic with the benthic population and thus prevent seasonal population differentiation. At the same time, frequent sexual reproduction and benthic-pelagic coupling maintain high clonal diversity in both habitats.
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Affiliation(s)
- Jacqueline Jerney
- Tvärminne Zoological StationUniversity of HelsinkiHankoFinland
- Marine Research CenterFinnish Environment InstituteHelsinkiFinland
| | | | - Satoshi Nagai
- National Research Institute of Fisheries ScienceYokohamaKanagawaJapan
| | - Bernd Krock
- Alfred‐Wegener‐Institut Helmholtz‐Zentrum für Polar‐ und MeeresforschungBremerhavenGermany
| | - Conny Sjöqvist
- Faculty of Science and Engineering, Environmental and Marine BiologyÅbo Akademi UniversityTurkuFinland
| | - Sanna Suikkanen
- Marine Research CenterFinnish Environment InstituteHelsinkiFinland
| | - Anke Kremp
- Marine Research CenterFinnish Environment InstituteHelsinkiFinland
- Present address:
Leibniz Institut für Ostseeforschung WarnemündeRostockGermany
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Pseudocochlodinium profundisulcus Resting Cysts Detected in the Ballast Tank Sediment of Ships Arriving in the Ports of China and North America and the Implications in the Species' Geographic Distribution and Possible Invasion. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 19:ijerph19010299. [PMID: 35010560 PMCID: PMC8751027 DOI: 10.3390/ijerph19010299] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 12/23/2021] [Accepted: 12/24/2021] [Indexed: 11/17/2022]
Abstract
Over the past several decades, much attention has been focused on the dispersal of aquatic nonindigenous species via ballast tanks of shipping vessels worldwide. The recently reclassified dinoflagellate Pseudocochlodinium profundisulcus (previously identified as Cochlodinium sp., Cochlodinium geminatum, or Polykrikos geminatus) was not reported in China until 2006. However, algal blooming events caused by this organism have been reported almost every year since then in the Pearl River Estuary and its adjacent areas in China. Whether P. profundisulcus is an indigenous or an invasive species has thus become an ecological question of great scientific and practical significance. In this study, we collected the sediments from ballast tanks of ships arriving in the ports of China and North America and characterized dinoflagellate resting cysts via a combined approach. We germinated two dark brownish cysts from the tank of an international ship (Vessel A) arriving at the Jiangyin Port (China) into vegetative cells and identified them as P. profundisulcus by light and scanning electron microscopy and phylogenetic analyses for partial LSU rDNA sequences. We also identified P. profundisulcus cyst from the ballast tank sediment of a ship (Vessel B) arriving in the port of North America via single-cyst PCR and cloning sequencing, which indicated that this species could be transported as resting cyst via ship. Since phylogenetic analyses based on partial LSU rDNA sequences could not differentiate all sequences among our cysts from those deposited in the NCBI database into sub-groups, all populations from China, Australia, Japan, and the original sources from which the cysts in the two vessels arrived in China and North America were carried over appeared to share a very recent common ancestor, and the species may have experienced a worldwide expansion recently. These results indicate that P. profundisulcus cysts may have been extensively transferred to many regions of the world via ships’ ballast tank sediments. While our work provides an exemplary case for both the feasibility and complexity (in tracking the source) of the bio-invasion risk via the transport of live resting cysts by ship’s ballast tanks, it also points out an orientation for future investigation.
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Brown ER, Moore SG, Gaul DA, Kubanek J. Differentiating toxic and nontoxic congeneric harmful algae using the non-polar metabolome. HARMFUL ALGAE 2021; 110:102129. [PMID: 34887009 DOI: 10.1016/j.hal.2021.102129] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 10/22/2021] [Accepted: 11/01/2021] [Indexed: 06/13/2023]
Abstract
Recognition and rejection of chemically defended prey is critical to maximizing fitness for predators. Paralytic shellfish toxins (PSTs) which strongly inhibit voltage-gated sodium channels in diverse animal taxa are produced by several species of the bloom-forming algal genus Alexandrium where they appear to function as chemical defenses against grazing copepods. Despite PSTs being produced and localized within phytoplankton cells, some copepods distinguish toxic from non-toxic prey, selectively ingesting less toxic cells, in ways that suggest cell surface recognition perhaps associated with non-polar metabolites. In this study LC/MS and NMR-based metabolomics revealed that the non-polar metabolomes of two toxic species (Alexandrium catenella and Alexandrium pacificum) vary considerably from their non-toxic congener Alexandrium tamarense despite all three being very closely related. Toxic and non-toxic Alexandrium spp. were distinguished from each other by metabolites belonging to seven lipid classes. Of these, 17 specific metabolites were significantly more abundant in both toxic A. catenella and A. pacificum compared to non-toxic A. tamarense suggesting that just a small portion of the observed metabolic variability is associated with toxicity. Future experiments aimed at deciphering chemoreception mechanisms of copepod perception of Alexandrium toxicity should consider these metabolites, and the broader lipid classes phosphatidylcholines and sterols, as potential candidate cues.
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Affiliation(s)
- Emily R Brown
- School of Biological Sciences, Georgia Institute of Technology, 950 Atlantic Dr, Atlanta, GA 30332, USA
| | - Sam G Moore
- School of Chemistry and Biochemistry, Georgia Institute of Technology, 901 Atlantic Dr, Atlanta, GA 30332, USA
| | - David A Gaul
- School of Chemistry and Biochemistry, Georgia Institute of Technology, 901 Atlantic Dr, Atlanta, GA 30332, USA
| | - Julia Kubanek
- School of Biological Sciences, Georgia Institute of Technology, 950 Atlantic Dr, Atlanta, GA 30332, USA; School of Chemistry and Biochemistry, Georgia Institute of Technology, 901 Atlantic Dr, Atlanta, GA 30332, USA; Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, 315 Ferst Dr, Atlanta, GA 30332, USA; Center for Microbial Dynamics and Infection, Georgia Institute of Technology, Atlanta, GA 30332, USA.
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Unsuspected intraspecific variability in the toxin production, growth and morphology of the dinoflagellate Alexandrium pacificum R.W. Litaker (Group IV) blooming in a South Western Mediterranean marine ecosystem, Annaba Bay (Algeria). Toxicon 2020; 180:79-88. [PMID: 32289356 DOI: 10.1016/j.toxicon.2020.04.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2019] [Revised: 04/04/2020] [Accepted: 04/07/2020] [Indexed: 11/23/2022]
Abstract
Physiological plasticity gives HABs species the ability to respond to variations in the surrounding environment. The aim of this study was to examine morphological and physiological variability in Alexandrium pacificum R.W. Litaker (Group IV) (former Alexandrium catenella) blooming in Annaba bay, Algeria. Monoclonal cultures of up to 30 strains of this neurotoxic dinoflagellate were established by the germination of single resting cysts from the surface sediment of this southern Mediterranean marine ecosystem. Ribotyping confirmed formally for the first time that A. pacificum is developing in Eastern Algerian waters. Toxin analyses of A. pacificum strains revealed substantial intraspecific variability in both the profile and toxin amount. However, the toxin profile of most strains is characterized by the dominance of GTX6 (up to 96 mol %) which is the less toxic paralytic molecule. The toxin concentrations in the isolated strains varied widely between 3.8 and 30.82 fmol cell-1. We observed an important variation in the growth rate of the studied A. pacificum strains with values ranging from 0.05 to 0.33 d-1. The lag time of the studied strains varied widely and ranged from 4 to 20 days. The intraspecific diversity could be a response to the selection pressure which may be exerted by different environmental conditions over time and which can be genetically and in turn physiologically expressed. This study highlights, for the first time, that the sediment of a limited area holds an important diversity of A. pacificum cysts which give when germinate populations with noticeable physiological plasticity. Consequently, this diversified natural populations allow an exceptional adaptation to specific environmental conditions to outcompete local microalgae and to establish HABs which could explain why this dinoflagellate is successful and expanding worldwide.
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Perini F, Bastianini M, Capellacci S, Pugliese L, DiPoi E, Cabrini M, Buratti S, Marini M, Penna A. Molecular methods for cost-efficient monitoring of HAB (harmful algal bloom) dinoflagellate resting cysts. MARINE POLLUTION BULLETIN 2019; 147:209-218. [PMID: 29910142 DOI: 10.1016/j.marpolbul.2018.06.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Revised: 03/13/2018] [Accepted: 06/05/2018] [Indexed: 06/08/2023]
Abstract
Cyst abundance and identity are essential for understanding and predicting blooms, and for assessing the dispersal of toxic target dinoflagellate species by natural or human mediated ways, as with ballast waters. The aim of this study was to apply rapid, specific and sensitive qPCR assays to enumerate toxic dinoflagellate cysts in sediment samples collected from Adriatic harbours. The molecular standard curves of various target species allowed obtaining the rDNA copy number per cyst. The analytical sensitivity for specific standard curves was determined to be 2 or 10 rDNA copies per reaction. The abundance varied in the range of 1-747 dinoflagellate cysts g-1 dry weight. The assays showed greater sensitivity as compared to counts by light microscopy. This qPCR method revealed a powerful tool for the quantification of cysts from toxic dinoflagellate resting stages in sediment samples from Adriatic ports.
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Affiliation(s)
- F Perini
- Department of Biomolecular Sciences, University of Urbino, Pesaro, Italy
| | - M Bastianini
- ISMAR-CNR, Istituto di Scienze Marine, Consiglio Nazionale delle Ricerche, Venezia, Italy
| | - S Capellacci
- Department of Biomolecular Sciences, University of Urbino, Pesaro, Italy
| | - L Pugliese
- Department of Biomolecular Sciences, University of Urbino, Pesaro, Italy
| | - E DiPoi
- OGS, Istituto Nazionale di Oceanografia e di Geofisica Sperimentale, Sgonico, Italy
| | - M Cabrini
- OGS, Istituto Nazionale di Oceanografia e di Geofisica Sperimentale, Sgonico, Italy
| | - S Buratti
- Fondazione Centro Ricerche Marine, Cesenatico, Italy
| | - M Marini
- ISMAR-CNR, Istituto di Scienze Marine, Consiglio Nazionale delle Ricerche, Ancona, Italy
| | - A Penna
- Department of Biomolecular Sciences, University of Urbino, Pesaro, Italy; ISMAR-CNR, Istituto di Scienze Marine, Consiglio Nazionale delle Ricerche, Ancona, Italy.
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Fischer AD, Brosnahan ML, Anderson DM. Quantitative Response of Alexandrium catenella Cyst Dormancy to Cold Exposure. Protist 2018; 169:645-661. [DOI: 10.1016/j.protis.2018.06.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2018] [Revised: 06/05/2018] [Accepted: 06/07/2018] [Indexed: 11/28/2022]
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Brandenburg KM, Wohlrab S, John U, Kremp A, Jerney J, Krock B, Van de Waal DB. Intraspecific trait variation and trade-offs within and across populations of a toxic dinoflagellate. Ecol Lett 2018; 21:1561-1571. [DOI: 10.1111/ele.13138] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 05/01/2018] [Accepted: 07/12/2018] [Indexed: 01/31/2023]
Affiliation(s)
- Karen M. Brandenburg
- Department of Aquatic Ecology; Netherlands Institute of Ecology (NIOO-KNAW); Droevendaalsesteeg 10 6708 PB Wageningen The Netherlands
| | - Sylke Wohlrab
- Department of Ecological Chemistry; Alfred Wegener Institute (AWI); Helmholtz Centre for Polar and Marine Research; Am Handelshafen 12 27570 Bremerhaven Germany
- Helmholtz-Institut für Funktionelle Marine Biodiversität (HIFMB); Ammerländer Heerstraße 231 23129 Oldenburg Germany
| | - Uwe John
- Department of Ecological Chemistry; Alfred Wegener Institute (AWI); Helmholtz Centre for Polar and Marine Research; Am Handelshafen 12 27570 Bremerhaven Germany
- Helmholtz-Institut für Funktionelle Marine Biodiversität (HIFMB); Ammerländer Heerstraße 231 23129 Oldenburg Germany
| | - Anke Kremp
- SYKE Marine Research Laboratory; Agnes Sjöbergin katu 2 FI-00790 Helsinki Finland
| | - Jacqueline Jerney
- SYKE Marine Research Laboratory; Agnes Sjöbergin katu 2 FI-00790 Helsinki Finland
| | - Bernd Krock
- Department of Ecological Chemistry; Alfred Wegener Institute (AWI); Helmholtz Centre for Polar and Marine Research; Am Handelshafen 12 27570 Bremerhaven Germany
| | - Dedmer B. Van de Waal
- Department of Aquatic Ecology; Netherlands Institute of Ecology (NIOO-KNAW); Droevendaalsesteeg 10 6708 PB Wageningen The Netherlands
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Sundqvist L, Godhe A, Jonsson PR, Sefbom J. The anchoring effect-long-term dormancy and genetic population structure. ISME JOURNAL 2018; 12:2929-2941. [PMID: 30068937 DOI: 10.1038/s41396-018-0216-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Revised: 05/18/2018] [Accepted: 06/11/2018] [Indexed: 11/09/2022]
Abstract
Understanding the genetic structure of populations is key to revealing past and present demographic and evolutionary processes in a species. In the past decade high genetic differentiation has been observed in many microbial species challenging the previous view of cosmopolitan distribution. Populations have displayed high genetic differentiation, even at small spatial scales, despite apparent high dispersal. Numerous species of microalgae have a life-history strategy that includes a long-term resting stage, which can accumulate in sediments and serve as refuge during adverse conditions. It is presently unclear how these seed banks affect the genetic structure of populations in aquatic environments. Here we provide a conceptual framework, using a simple model, to show that long-term resting stages have an anchoring effect on populations leading to increased genetic diversity and population differentiation in the presence of gene flow. The outcome that species with resting stages have a higher degree of genetic differentiation compared to species without, is supported by empirical data obtained from a systematic literature review. With this work we propose that seed banks in aquatic microalgae play an important role in the contradicting patterns of gene flow, and ultimately the adaptive potential and population dynamics in species with long-term resting stages.
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Affiliation(s)
- Lisa Sundqvist
- Department of Marine Sciences, University of Gothenburg, Box 461, Göteborg, SE, 40530, Sweden
| | - Anna Godhe
- Department of Marine Sciences, University of Gothenburg, Box 461, Göteborg, SE, 40530, Sweden
| | - Per R Jonsson
- Department of Marine Sciences - Tjärnö, University of Gothenburg, Strömstad, SE, 45296, Sweden
| | - Josefin Sefbom
- Department of Marine Sciences, University of Gothenburg, Box 461, Göteborg, SE, 40530, Sweden. .,Department of Biology, Laboratory of Protistology and Aquatic Ecology, Ghent University, Krijgslaan 281-S8, Gent, B-9000, Belgium.
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Figueroa RI, Estrada M, Garcés E. Life histories of microalgal species causing harmful blooms: Haploids, diploids and the relevance of benthic stages. HARMFUL ALGAE 2018; 73:44-57. [PMID: 29602506 DOI: 10.1016/j.hal.2018.01.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Revised: 01/18/2018] [Accepted: 01/18/2018] [Indexed: 05/25/2023]
Abstract
In coastal and offshore waters, Harmful Algal Blooms (HABs) currently threaten the well-being of coastal countries. These events, which can be localized or involve wide-ranging areas, pose risks to human health, marine ecosystems, and economic resources, such as tourism, fisheries, and aquaculture. Dynamics of HABs vary from one site to another, depending on the hydrographic and ecological conditions. The challenge in investigating HABs is that they are caused by organisms from multiple algal classes, each with its own unique features, including different life histories. The complete algal life cycle has been determined in <1% of the described species, although elucidation of the life cycles of bloom-forming species is essential in developing preventative measures. The knowledge obtained thus far has confirmed the complexity of the algal life cycle, which is composed of discrete life stages whose morphology, ecological niche (plankton/benthos), function, and lifespan vary. The factors that trigger transitions between the different stages in nature are mostly unknown, but it is clear that an understanding of this process provides the key to effectively forecasting bloom recurrence, maintenance, and decline. Planktonic stages constitute an ephemeral phase of the life cycle of most species whereas resistant, benthic stages enable a species to withstand adverse conditions for prolonged periods, thus providing dormant reservoirs for eventual blooms and facilitating organismal dispersal. Here we review current knowledge of the life cycle strategies of major groups of HAB producers in marine and brackish waters. Rather than providing a comprehensive discussion, the objective was to highlight several of the research milestones that have changed our understanding of the plasticity and frequency of the different life cycle stages as well as the transitions between them. We also discuss the relevance of benthic and planktonic forms and their implications for HAB dynamics.
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Affiliation(s)
- Rosa Isabel Figueroa
- Instituto Español de Oceanografía (IEO), C.O. Vigo, 36280 Vigo, Spain; Aquatic Ecology Division, Department of Biology, Lund University, S-22362 Lund, Sweden.
| | - Marta Estrada
- Departament de Biología Marina i Oceanografía, Institut de Ciències del Mar, Consejo Superior de Investigaciones Científicas (CSIC), Pg. Marítim de la Barceloneta 37-49, 08003 Barcelona, Spain
| | - Esther Garcés
- Departament de Biología Marina i Oceanografía, Institut de Ciències del Mar, Consejo Superior de Investigaciones Científicas (CSIC), Pg. Marítim de la Barceloneta 37-49, 08003 Barcelona, Spain
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12
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Litaker RW, Holland WC, Hardison DR, Pisapia F, Hess P, Kibler SR, Tester PA. Ciguatoxicity of Gambierdiscus and Fukuyoa species from the Caribbean and Gulf of Mexico. PLoS One 2017; 12:e0185776. [PMID: 29045489 PMCID: PMC5646788 DOI: 10.1371/journal.pone.0185776] [Citation(s) in RCA: 83] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2017] [Accepted: 09/19/2017] [Indexed: 11/22/2022] Open
Abstract
Dinoflagellate species belonging to the genera Gambierdiscus and Fukuyoa produce ciguatoxins (CTXs), potent neurotoxins that concentrate in fish causing ciguatera fish poisoning (CFP) in humans. While the structures and toxicities of ciguatoxins isolated from fish in the Pacific and Caribbean are known, there are few data on the variation in toxicity between and among species of Gambierdiscus and Fukuyoa. Quantifying the differences in species-specific toxicity is especially important to developing an effective cell-based risk assessment strategy for CFP. This study analyzed the ciguatoxicity of 33 strains representing seven Gambierdiscus and one Fukuyoa species using a cell based Neuro-2a cytotoxicity assay. All strains were isolated from either the Caribbean or Gulf of Mexico. The average toxicity of each species was inversely proportional to growth rate, suggesting an evolutionary trade-off between an investment in growth versus the production of defensive compounds. While there is 2- to 27-fold variation in toxicity within species, there was a 1740-fold difference between the least and most toxic species. Consequently, production of CTX or CTX-like compounds is more dependent on the species present than on the random occurrence of high or low toxicity strains. Seven of the eight species tested (G. belizeanus, G. caribaeus, G. carolinianus, G. carpenteri, Gambierdiscus ribotype 2, G. silvae and F. ruetzleri) exhibited low toxicities, ranging from 0 to 24.5 fg CTX3C equivalents cell-1, relative to G. excentricus, which had a toxicity of 469 fg CTX3C eq. cell-1. Isolates of G. excentricus from other regions have shown similarly high toxicities. If the hypothesis that G. excentricus is the primary source of ciguatoxins in the Atlantic is confirmed, it should be possible to identify areas where CFP risk is greatest by monitoring only G. excentricus abundance using species-specific molecular assays.
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Affiliation(s)
- R. Wayne Litaker
- National Ocean Service, National Centers for Coastal Ocean Science, Center for Coastal Fisheries and Habitat Research, Beaufort, North Carolina, United States of America
- * E-mail:
| | - William C. Holland
- National Ocean Service, National Centers for Coastal Ocean Science, Center for Coastal Fisheries and Habitat Research, Beaufort, North Carolina, United States of America
| | - D. Ransom Hardison
- National Ocean Service, National Centers for Coastal Ocean Science, Center for Coastal Fisheries and Habitat Research, Beaufort, North Carolina, United States of America
| | - Francesco Pisapia
- L'Institut Français de Recherche pour l'Exploitation de la Mer, Laboratoire Phycotoxines, Nantes, France
| | - Philipp Hess
- L'Institut Français de Recherche pour l'Exploitation de la Mer, Laboratoire Phycotoxines, Nantes, France
| | - Steven R. Kibler
- National Ocean Service, National Centers for Coastal Ocean Science, Center for Coastal Fisheries and Habitat Research, Beaufort, North Carolina, United States of America
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13
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Lundholm N, Ribeiro S, Godhe A, Rostgaard Nielsen L, Ellegaard M. Exploring the impact of multidecadal environmental changes on the population genetic structure of a marine primary producer. Ecol Evol 2017; 7:3132-3142. [PMID: 28480012 PMCID: PMC5415532 DOI: 10.1002/ece3.2906] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Revised: 02/13/2017] [Accepted: 02/21/2017] [Indexed: 01/29/2023] Open
Abstract
Many marine protists form resting stages that can remain viable in coastal sediments for several decades. Their long‐term survival offers the possibility to explore the impact of changes in environmental conditions on population dynamics over multidecadal time scales. Resting stages of the phototrophic dinoflagellate Pentapharsodinium dalei were isolated and germinated from five layers in dated sediment cores from Koljö fjord, Sweden, spanning ca. 1910–2006. This fjord has, during the last century, experienced environmental fluctuations linked to hydrographic variability mainly driven by the North Atlantic Oscillation. Population genetic analyses based on six microsatellite markers revealed high genetic diversity and suggested that samples belonged to two clusters of subpopulations that have persisted for nearly a century. We observed subpopulation shifts coinciding with changes in hydrographic conditions. The large degree of genetic diversity and the potential for both fluctuation and recovery over longer time scales documented here, may help to explain the long‐term success of aquatic protists that form resting stages.
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Affiliation(s)
- Nina Lundholm
- The Natural History Museum of Denmark University of Copenhagen Copenhagen K Denmark
| | - Sofia Ribeiro
- Glaciology and Climate Department Geological Survey of Denmark and Greenland (GEUS) Copenhagen K Denmark
| | - Anna Godhe
- Department of Marine Sciences University of Gothenburg Göteborg Sweden
| | - Lene Rostgaard Nielsen
- Deparment of Geosciences and Natural Resource Management University of Copenhagen Frederiksberg Denmark
| | - Marianne Ellegaard
- Department of Plant and Environmental Sciences University of Copenhagen Frederiksberg Denmark
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14
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Mardones JI, Bolch C, Guzmán L, Paredes J, Varela D, Hallegraeff GM. Role of resting cysts in Chilean Alexandrium catenella dinoflagellate blooms revisited. HARMFUL ALGAE 2016; 55:238-249. [PMID: 28073537 DOI: 10.1016/j.hal.2016.03.020] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Revised: 03/29/2016] [Accepted: 03/29/2016] [Indexed: 05/16/2023]
Abstract
The detection of sparse Alexandrium catenella-resting cysts in sediments of southern Chilean fjords has cast doubts on their importance in the recurrence of massive toxic dinoflagellate blooms in the region. The role of resting cysts and the existence of different regional Chilean populations was studied by culturing and genetic approaches to define: (1) cyst production; (2) dormancy period; (3) excystment success; (4) offspring viability and (5) strain mating compatibility. This study newly revealed a short cyst dormancy (minimum 69 days), the role of key abiotic factors (in decreasing order salinity, irradiance, temperature and nutrients) controlling cyst germination (max. 60%) and germling growth rates (up to 0.36-0.52div.day-1). Amplified fragment length polymorphism (AFLP) characterization showed significant differences in genetic distances (GD) among A. catenella populations that were primarily determined by the geographical origin of isolates and most likely driven by oceanographic dispersal barriers. A complex heterothallic mating system pointed to variable reproductive compatibility (RCs) among Chilean strains that was high among northern (Los Lagos/North Aysén) and southern populations (Magallanes), but limited among the genetically differentiated central (South Aysén) populations. Field cyst surveys after a massive 2009 bloom event revealed the existence of exceptional high cyst densities in particular areas of the fjords (max. 14.627cystscm-3), which contrast with low cyst concentrations (<221.3cystscm-3) detected by previous oceanographic campaigns. In conclusion, the present study suggests that A. catenella resting cysts play a more important role in the success of this species in Chilean fjords than previously thought. Results from in vitro experiments suggest that pelagic-benthic processes can maintain year-round low vegetative cell concentrations in the water column, but also can explain the detection of high cysts aggregations after the 2009-bloom event. Regional drivers that lead to massive outbreaks, however, are still unknown but potential scenarios are discussed.
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Affiliation(s)
- Jorge I Mardones
- Institute for Marine and Antarctic Studies (IMAS), University of Tasmania, Private Bag 129, Hobart, Tasmania 7001, Australia.
| | - Chris Bolch
- Institute for Marine and Antarctic Studies (IMAS), University of Tasmania, Private Bag 129, Hobart, Tasmania 7001, Australia
| | - Leonardo Guzmán
- Instituto de Fomento Pesquero, IFOP, Balmaceda 252, Puerto Montt 5480000, Chile
| | - Javier Paredes
- Centro i-mar, Universidad de los Lagos, Casilla 557, Puerto Montt, Chile; Facultad de Ciencias del Mar, Departamento de Biología Marina, Programa de Doctorado en Biología y Ecología Aplicada, Universidad Católica del Norte, Chile
| | - Daniel Varela
- Centro i-mar, Universidad de los Lagos, Casilla 557, Puerto Montt, Chile
| | - Gustaaf M Hallegraeff
- Institute for Marine and Antarctic Studies (IMAS), University of Tasmania, Private Bag 129, Hobart, Tasmania 7001, Australia
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15
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Lu Y, Wohlrab S, Groth M, Glöckner G, Guillou L, John U. Transcriptomic profiling of Alexandrium fundyense
during physical interaction with or exposure to chemical signals from the parasite Amoebophrya. Mol Ecol 2016; 25:1294-307. [DOI: 10.1111/mec.13566] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2015] [Revised: 01/08/2016] [Accepted: 01/26/2016] [Indexed: 01/02/2023]
Affiliation(s)
- Yameng Lu
- Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung; Bremerhaven Germany
| | - Sylke Wohlrab
- Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung; Bremerhaven Germany
| | - Marco Groth
- Leibniz-Institute for Age Research; Fritz Lipmann Institute Jena; Jena Germany
| | - Gernot Glöckner
- Biochemistry I; Medical Faculty; University of Cologne and Institute for Freshwater Ecology and Inland Fisheries (IGB); Berlin Germany
| | - Laure Guillou
- Laboratoire Adaptation et Diversité en Milieu Marin; CNRS; UMR 7144, Place Georges Teissier, CS90074 29688 Roscoff Cedex France
- Université Pierre et Marie Curie-Paris 6; Sorbonne Universités; UMR 7144, Station Biologique de Roscoff, Place Georges Teissier, CS90074 29688 Roscoff Cedex France
| | - Uwe John
- Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung; Bremerhaven Germany
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16
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Sjöqvist C, Godhe A, Jonsson PR, Sundqvist L, Kremp A. Local adaptation and oceanographic connectivity patterns explain genetic differentiation of a marine diatom across the North Sea-Baltic Sea salinity gradient. Mol Ecol 2015; 24:2871-85. [PMID: 25892181 PMCID: PMC4692096 DOI: 10.1111/mec.13208] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Revised: 04/13/2015] [Accepted: 04/16/2015] [Indexed: 01/22/2023]
Abstract
Drivers of population genetic structure are still poorly understood in marine micro-organisms. We exploited the North Sea-Baltic Sea transition for investigating the seascape genetics of a marine diatom, Skeletonema marinoi. Eight polymorphic microsatellite loci were analysed in 354 individuals from ten locations to analyse population structure of the species along a 1500-km-long salinity gradient ranging from 3 to 30 psu. To test for salinity adaptation, salinity reaction norms were determined for sets of strains originating from three different salinity regimes of the gradient. Modelled oceanographic connectivity was compared to directional relative migration by correlation analyses to examine oceanographic drivers. Population genetic analyses showed distinct genetic divergence of a low-salinity Baltic Sea population and a high-salinity North Sea population, coinciding with the most evident physical dispersal barrier in the area, the Danish Straits. Baltic Sea populations displayed reduced genetic diversity compared to North Sea populations. Growth optima of low salinity isolates were significantly lower than those of strains from higher native salinities, indicating local salinity adaptation. Although the North Sea-Baltic Sea transition was identified as a barrier to gene flow, migration between Baltic Sea and North Sea populations occurred. However, the presence of differentiated neutral markers on each side of the transition zone suggests that migrants are maladapted. It is concluded that local salinity adaptation, supported by oceanographic connectivity patterns creating an asymmetric migration pattern between the Baltic Sea and the North Sea, determines genetic differentiation patterns in the transition zone.
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Affiliation(s)
- C Sjöqvist
- Environmental and Marine Biology, Åbo Akademi University, Artillerigatan 6, 20520, Åbo, Finland.,Finnish Environmental Institute/Marine Research Centre, PB 140, 00251, Helsinki, Finland
| | - A Godhe
- Department of Biological and Environmental Sciences, University of Gothenburg, PB 461, SE 40530, Göteborg, Sweden
| | - P R Jonsson
- Department of Biological and Environmental Sciences - Tjärnö, University of Gothenburg, SE 45296, Strömstad, Sweden
| | - L Sundqvist
- Department of Biological and Environmental Sciences, University of Gothenburg, PB 461, SE 40530, Göteborg, Sweden
| | - A Kremp
- Finnish Environmental Institute/Marine Research Centre, PB 140, 00251, Helsinki, Finland
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17
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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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18
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John U, Tillmann U, Hülskötter J, Alpermann TJ, Wohlrab S, Van de Waal DB. Intraspecific facilitation by allelochemical mediated grazing protection within a toxigenic dinoflagellate population. Proc Biol Sci 2015; 282:20141268. [PMID: 25411447 DOI: 10.1098/rspb.2014.1268] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Dinoflagellates are a major cause of harmful algal blooms (HABs), with consequences for coastal marine ecosystem functioning and services. Alexandrium fundyense (previously Alexandrium tamarense) is one of the most abundant and widespread toxigenic species in the temperate Northern and Southern Hemisphere and produces paralytic shellfish poisoning toxins as well as lytic allelochemical substances. These bioactive compounds may support the success of A. fundyense and its ability to form blooms. Here we investigate the impact of grazing on monoclonal and mixed set-ups of highly (Alex2) and moderately (Alex4) allelochemically active A. fundyense strains and a non-allelochemically active conspecific (Alex5) by the heterotrophic dinoflagellate Polykrikos kofoidii. While Alex4 and particularly Alex5 were strongly grazed by P. kofoidii when offered alone, both strains grew well in the mixed assemblages (Alex4 + Alex5 and Alex2 + Alex5). Hence, the allelochemical active strains facilitated growth of the non-active strain by protecting the population as a whole against grazing. Based on our results, we argue that facilitation among clonal lineages within a species may partly explain the high genotypic and phenotypic diversity of Alexandrium populations. Populations of Alexandrium may comprise multiple cooperative traits that act in concert with intraspecific facilitation, and hence promote the success of this notorious HAB species.
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Affiliation(s)
- Uwe John
- Alfred Wegener Institute for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany
| | - Urban Tillmann
- Alfred Wegener Institute for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany
| | - Jennifer Hülskötter
- Alfred Wegener Institute for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany
| | - Tilman J Alpermann
- Senckenberg Research Institute and Natural History Museum Frankfurt, Senckenberganlage 25, 60325 Frankfurt a. M., Germany
| | - Sylke Wohlrab
- Alfred Wegener Institute for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany
| | - Dedmer B Van de Waal
- Department of Aquatic Ecology, Netherlands Institute of Ecology, PO Box 50, 6700 AB Wageningen, The Netherlands
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19
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Van den Wyngaert S, Möst M, Freimann R, Ibelings BW, Spaak P. Hidden diversity in the freshwater planktonic diatom Asterionella formosa. Mol Ecol 2015; 24:2955-72. [PMID: 25919789 DOI: 10.1111/mec.13218] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Revised: 04/23/2015] [Accepted: 04/24/2015] [Indexed: 12/20/2022]
Abstract
Many freshwater and marine algal species are described as having cosmopolitan distributions. Whether these widely distributed morphologically similar algae also share a similar gene pool remains often unclear. In the context of island biogeography theory, stronger spatial isolation deemed typical of freshwater lakes should restrict gene flow and lead to higher genetic differentiation among lakes. Using nine microsatellite loci, we investigate the genetic diversity of a widely distributed freshwater planktonic diatom, Asterionella formosa, across different lakes in Switzerland and the Netherlands. We applied a hierarchical spatial sampling design to determine the geographical scale at which populations are structured. A subset of the isolates was additionally analysed using amplified fragment length polymorphism (AFLP) markers. Our results revealed complex and unexpected population structure in A. formosa with evidence for both restricted and moderate to high gene flow at the same time. Different genetic markers (microsatellites and AFLPs) analysed with a variety of multivariate methods consistently revealed that genetic differentiation within lakes was much stronger than among lakes, indicating the presence of cryptic species within A. formosa. We conclude that the hidden diversity found in this study is expected to have implications for the further use of A. formosa in biogeographical, conservation and ecological studies. Further research using species-level phylogenetic markers is necessary to place the observed differentiation in an evolutionary context of speciation.
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Affiliation(s)
- S Van den Wyngaert
- Aquatic Ecology, Eawag, Ueberlandstrasse 133, PO Box 611, CH-8600, Duebendorf, Switzerland.,Institute of Integrative Biology, ETH Zürich, CH-8092, Zürich, Switzerland.,Experimental Limnology, Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB) Berlin, Alte Fischerhütte 2, 16775, Stechlin, Germany
| | - M Möst
- Aquatic Ecology, Eawag, Ueberlandstrasse 133, PO Box 611, CH-8600, Duebendorf, Switzerland.,Institute of Integrative Biology, ETH Zürich, CH-8092, Zürich, Switzerland.,Department of Zoology, University of Cambridge, Downing St., Cambridge, CB2 3EJ, UK
| | - R Freimann
- Institute of Molecular Health Sciences, ETH-Zürich, Otto-Stern-Weg 7, CH-8093, Zürich, Switzerland
| | - B W Ibelings
- Aquatic Ecology, Eawag, Ueberlandstrasse 133, PO Box 611, CH-8600, Duebendorf, Switzerland.,Institute of Integrative Biology, ETH Zürich, CH-8092, Zürich, Switzerland.,Institut F.-A. Forel, Université de Genève, 10 Route de Suisse, CH-12090, Versoix, Switzerland
| | - P Spaak
- Aquatic Ecology, Eawag, Ueberlandstrasse 133, PO Box 611, CH-8600, Duebendorf, Switzerland.,Institute of Integrative Biology, ETH Zürich, CH-8092, Zürich, Switzerland
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20
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Jurdíková K, Kulichová J, Bestová H, Leliaert F, Skaloud P. Exploration of nuclear DNA markers for population structure assessment in the desmid Micrasterias rotata (Zygnematophyceae, Streptophyta). J Eukaryot Microbiol 2014; 61:509-19. [PMID: 24961475 DOI: 10.1111/jeu.12130] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2014] [Revised: 03/22/2014] [Accepted: 03/23/2014] [Indexed: 11/26/2022]
Abstract
Freshwater green microalgae are diverse and widely distributed across the globe, yet the population structuring of these organisms is poorly understood. We assessed the degree of genetic diversity and differentiation of the desmid species, Micrasterias rotata. First, we compared the sequences of four nuclear regions (actin, gapC1, gapC2, and oee1) in 25 strains and selected the gapC1 and actin regions as the most appropriate markers for population structure assessment in this species. Population genetic structure was subsequently analyzed, based on seven populations from the Czech Republic and Ireland. Hudson's Snn statistics indicated that nearest-neighbor sequences occurred significantly more frequently within geographical populations than within the wider panmictic population. Moreover, Irish populations consistently showed higher genetic diversity than the Czech samples. These results are in accordance with the unbalanced distribution of alleles in many land plant species; however, the large genetic diversity in M. rotata differs from levels of genetic diversity found in most land plants.
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Affiliation(s)
- Katarína Jurdíková
- Department of Botany, Faculty of Science, Charles University in Prague, Benátská 2, Praha, CZ, 12801, Czech Republic
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21
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Van de Waal DB, Eberlein T, John U, Wohlrab S, Rost B. Impact of elevated pCO2 on paralytic shellfish poisoning toxin content and composition in Alexandrium tamarense. Toxicon 2014; 78:58-67. [DOI: 10.1016/j.toxicon.2013.11.011] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2013] [Revised: 11/15/2013] [Accepted: 11/20/2013] [Indexed: 10/25/2022]
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22
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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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23
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Bravo I, Figueroa RI. Towards an Ecological Understanding of Dinoflagellate Cyst Functions. Microorganisms 2014; 2:11-32. [PMID: 27694774 PMCID: PMC5029505 DOI: 10.3390/microorganisms2010011] [Citation(s) in RCA: 100] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Revised: 11/17/2013] [Accepted: 11/23/2013] [Indexed: 01/10/2023] Open
Abstract
The life cycle of many dinoflagellates includes at least one nonflagellated benthic stage (cyst). In the literature, the different types of dinoflagellate cysts are mainly defined based on morphological (number and type of layers in the cell wall) and functional (long- or short-term endurance) differences. These characteristics were initially thought to clearly distinguish pellicle (thin-walled) cysts from resting (double-walled) dinoflagellate cysts. The former were considered short-term (temporal) and the latter long-term (resting) cysts. However, during the last two decades further knowledge has highlighted the great intricacy of dinoflagellate life histories, the ecological significance of cyst stages, and the need to clarify the functional and morphological complexities of the different cyst types. Here we review and, when necessary, redefine the concepts of resting and pellicle cysts, examining both their structural and their functional characteristics in the context of the life cycle strategies of several dinoflagellate species.
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Affiliation(s)
- Isabel Bravo
- Spanish Oceanographic Institute, Subida a Radio Faro 50, Vigo 36390, Spain.
| | - Rosa Isabel Figueroa
- Spanish Oceanographic Institute, Subida a Radio Faro 50, Vigo 36390, Spain.
- Aquatic Ecology, Department of Biology, Lund University, Lund 22362, Sweden.
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Tahvanainen P, Alpermann TJ, Figueroa RI, John U, Hakanen P, Nagai S, Blomster J, Kremp A. Patterns of post-glacial genetic differentiation in marginal populations of a marine microalga. PLoS One 2012; 7:e53602. [PMID: 23300940 PMCID: PMC3534129 DOI: 10.1371/journal.pone.0053602] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2012] [Accepted: 11/30/2012] [Indexed: 11/18/2022] Open
Abstract
This study investigates the genetic structure of an eukaryotic microorganism, the toxic dinoflagellate Alexandrium ostenfeldii, from the Baltic Sea, a geologically young and ecologically marginal brackish water estuary which is predicted to support evolution of distinct, genetically impoverished lineages of marine macroorganisms. Analyses of the internal transcribed spacer (ITS) sequences and Amplified Fragment Length Polymorphism (AFLP) of 84 A. ostenfeldii isolates from five different Baltic locations and multiple external sites revealed that Baltic A. ostenfeldii is phylogenetically differentiated from other lineages of the species and micro-geographically fragmented within the Baltic Sea. Significant genetic differentiation (F(ST)) between northern and southern locations was correlated to geographical distance. However, instead of discrete genetic units or continuous genetic differentiation, the analysis of population structure suggests a complex and partially hierarchic pattern of genetic differentiation. The observed pattern suggests that initial colonization was followed by local differentiation and varying degrees of dispersal, most likely depending on local habitat conditions and prevailing current systems separating the Baltic Sea populations. Local subpopulations generally exhibited low levels of overall gene diversity. Association analysis suggests predominately asexual reproduction most likely accompanied by frequency shifts of clonal lineages during planktonic growth. Our results indicate that the general pattern of genetic differentiation and reduced genetic diversity of Baltic populations found in large organisms also applies to microscopic eukaryotic organisms.
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Affiliation(s)
- Pia Tahvanainen
- Marine Research Centre, Finnish Environment Institute, Helsinki, Finland.
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25
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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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26
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Lebret K, Kritzberg ES, Figueroa R, Rengefors K. Genetic diversity within and genetic differentiation between blooms of a microalgal species. Environ Microbiol 2012; 14:2395-404. [PMID: 22568551 PMCID: PMC3466416 DOI: 10.1111/j.1462-2920.2012.02769.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The field of genetic diversity in protists, particularly phytoplankton, is under expansion. However, little is known regarding variation in genetic diversity within populations over time. The aim of our study was to investigate intrapopulation genetic diversity and genetic differentiation in the freshwater bloom-forming microalga Gonyostomum semen (Raphidophyceae). The study covered a 2-year period including all phases of the bloom. Amplified fragment length polymorphism (AFLP) was used to determine the genetic structure and diversity of the population. Our results showed a significant differentiation between samples collected during the two blooms from consecutive years. Also, an increase of gene diversity and a loss of differentiation among sampling dates were observed over time within a single bloom. The latter observations may reflect the continuous germination of cysts from the sediment. The life cycle characteristics of G. semen, particularly reproduction and recruitment, most likely explain a high proportion of the observed variation. This study highlights the importance of the life cycle for the intraspecific genetic diversity of microbial species, which alternates between sexual and asexual reproduction.
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Affiliation(s)
- Karen Lebret
- Aquatic Ecology, Department of Biology, Lund University, Ecology Building, Lund SE-223 62, Sweden.
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27
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Abstract
A fundamental question in ecology is whether microorganisms follow the same patterns as multicellular organisms when it comes to population structure and levels of genetic diversity. Enormous population sizes, predominately asexual reproduction and presumably high dispersal because of small body size could have profound implications on their genetic diversity and population structure. Here, we have analysed the population genetic structure in a lake-dwelling microbial eukaryote (dinoflagellate) and tested the hypothesis that there is population genetic differentiation among nearby lake subpopulations. This dinoflagellate occurs in the marine-derived saline lakes of the Vestfold Hills, Antarctica, which are ice-covered most of the year. Clonal strains were isolated from four different lakes and were genotyped using amplified fragment length polymorphism (AFLP). Our results show high genetic differentiation among lake populations despite their close geographic proximity (<9 km). Moreover, genotype diversity was high within populations. Gene flow in this system is clearly limited, either because of physical or biological barriers. Our results discard the null hypothesis that there is free gene flow among protist lake populations. Instead, limnetic protist populations may differentiate genetically, and lakes act as ecological islands even on the microbial scale.
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Affiliation(s)
- K Rengefors
- Department of Biology, Lund University, Ecology Building, SE-22362 Lund, Sweden.
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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: 354] [Impact Index Per Article: 29.5] [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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Anderson DM, Cembella AD, Hallegraeff GM. Progress in understanding harmful algal blooms: paradigm shifts and new technologies for research, monitoring, and management. ANNUAL REVIEW OF MARINE SCIENCE 2012; 4:143-76. [PMID: 22457972 PMCID: PMC5373096 DOI: 10.1146/annurev-marine-120308-081121] [Citation(s) in RCA: 442] [Impact Index Per Article: 36.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
The public health, tourism, fisheries, and ecosystem impacts from harmful algal blooms (HABs) have all increased over the past few decades. This has led to heightened scientific and regulatory attention, and the development of many new technologies and approaches for research and management. This, in turn, is leading to significant paradigm shifts with regard to, e.g., our interpretation of the phytoplankton species concept (strain variation), the dogma of their apparent cosmopolitanism, the role of bacteria and zooplankton grazing in HABs, and our approaches to investigating the ecological and genetic basis for the production of toxins and allelochemicals. Increasingly, eutrophication and climate change are viewed and managed as multifactorial environmental stressors that will further challenge managers of coastal resources and those responsible for protecting human health. Here we review HAB science with an eye toward new concepts and approaches, emphasizing, where possible, the unexpected yet promising new directions that research has taken in this diverse field.
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Affiliation(s)
- Donald M Anderson
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, USA.
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Barreto FS, Tomas CR, McCartney MA. AFLP Fingerprinting Shows that a Single Prymnesium parvum Harmful Algal Bloom Consists of Multiple Clones. J Hered 2011; 102:747-52. [DOI: 10.1093/jhered/esr081] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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31
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Erdner DL, Richlen M, McCauley LAR, Anderson DM. Diversity and dynamics of a widespread bloom of the toxic dinoflagellate Alexandrium fundyense. PLoS One 2011; 6:e22965. [PMID: 21829565 PMCID: PMC3146535 DOI: 10.1371/journal.pone.0022965] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2011] [Accepted: 07/03/2011] [Indexed: 11/25/2022] Open
Abstract
Historically, cosmopolitan phytoplankton species were presumed to represent largely unstructured populations. However, the recent development of molecular tools to examine genetic diversity have revealed differences in phytoplankton taxa across geographic scales and provided insight into the physiology and ecology of blooms. Here we describe the genetic analysis of an extensive bloom of the toxic dinoflagellate Alexandrium fundyense that occurred in the Gulf of Maine in 2005. This bloom was notable for its intensity and duration, covering hundreds of kilometers and persisting for almost two months. Genotypic analyses based on microsatellite marker data indicate that the open waters of the northeastern U.S. harbor a single regional population of A. fundyense comprising two genetically distinct sub-populations. These subpopulations were characteristic of early- and late-bloom samples and were derived from the northern and southern areas of the bloom, respectively. The temporal changes observed during this study provide clear evidence of succession during a continuous bloom and show that selection can act on the timescale of weeks to significantly alter the representation of genotypes within a population. The effects of selection on population composition and turnover would be magnified if sexual reproduction were likewise influenced by environmental conditions. We hypothesize that the combined effects of differential growth and reproduction rates serves to reduce gene flow between the sub-populations, reinforcing population structure while maintaining the diversity of the overall regional population.
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Affiliation(s)
- Deana L Erdner
- University of Texas Marine Science Institute, Port Aransas, Texas, United States of America.
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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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33
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Hundred years of genetic structure in a sediment revived diatom population. Proc Natl Acad Sci U S A 2011; 108:4252-7. [PMID: 21282612 DOI: 10.1073/pnas.1013528108] [Citation(s) in RCA: 137] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
This paper presents research on the genetic structure and diversity of populations of a common marine protist and their changes over time. The bloom-forming diatom Skeletonema marinoi was used as a model organism. Strains were revived from anoxic discrete layers of a (210)Pb-dated sediment core accumulated over more than 100 y, corresponding to >40,000 diatom mitotic generations. The sediment core was sampled from the highly eutrophic Mariager Fjord in Denmark. The genetic structure of S. marinoi was examined using microsatellite markers, enabling exploration of changes through time and of the effect of environmental fluctuations. The results showed a stable population structure among and within the examined sediment layers, and a similar genetic structure has been maintained over thousands of generations. However, established populations from inside the fjord were highly differentiated from open-sea populations. Despite constant water exchange and influx of potential colonizers into the fjord, the populations do not mix. One fjord population, accumulated in 1980, was significantly differentiated from the other groups of strains isolated from the fjord. This differentiation could have resulted from the status of Mariager Fjord, which was considered hypereutrophic, around 1980. There was no significant genetic difference between pre- and posteutrophication groups of strains. Our data show that dispersal potential and generation time do not have a large impact on the genetic structuring of the populations investigated here. Instead, the environmental conditions, such as the extreme eutrophication of the Mariager Fjord, are deemed more important.
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Sieg RD, Poulson-Ellestad KL, Kubanek J. Chemical ecology of the marine plankton. Nat Prod Rep 2011; 28:388-99. [DOI: 10.1039/c0np00051e] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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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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37
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GODHE ANNA, HÄRNSTRÖM KAROLINA. Linking the planktonic and benthic habitat: genetic structure of the marine diatom Skeletonema marinoi. Mol Ecol 2010; 19:4478-90. [DOI: 10.1111/j.1365-294x.2010.04841.x] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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38
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SALA-BOZANO MARIA, KETMAIER VALERIO, MARIANI STEFANO. Contrasting signals from multiple markers illuminate population connectivity in a marine fish. Mol Ecol 2009; 18:4811-26. [DOI: 10.1111/j.1365-294x.2009.04404.x] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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39
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Ma H, Krock B, Tillmann U, Cembella A. Preliminary characterization of extracellular allelochemicals of the toxic marine dinoflagellate Alexandrium tamarense using a Rhodomonas salina bioassay. Mar Drugs 2009; 7:497-522. [PMID: 20098594 PMCID: PMC2810232 DOI: 10.3390/md7040497] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2009] [Revised: 10/28/2009] [Accepted: 10/29/2009] [Indexed: 11/30/2022] Open
Abstract
Members of the marine dinoflagellate genus Alexandrium are known to exude allelochemicals, unrelated to well-known neurotoxins (PSP-toxins, spirolides), with negative effects on other phytoplankton and marine grazers. Physico/chemical characterization of extracellular lytic compounds of A. tamarense, quantified by Rhodomonas salina bioassay, showed that the lytic activity, and hence presumably the compounds were stable over wide ranges of temperatures and pH and were refractory to bacterial degradation. Two distinct lytic fractions were collected by reversed-phase solid-phase extraction. The more hydrophilic fraction accounted for about 2% of the whole lytic activity of the A. tamarense culture supernatant, while the less hydrophilic one accounted for about 98% of activity. Although temporal stability of the compounds is high, substantial losses were evident during purification. Lytic activity was best removed from aqueous phase with chloroform-methanol (3:1). A “pseudo-loss” of lytic activity in undisturbed and low-concentrated samples and high activity of an emulsion between aqueous and n-hexane phase after liquid-liquid partition are strong evidence for the presence of amphipathic compounds. Lytic activity in the early fraction of gel permeation chromatography and lack of activity after 5 kD ultrafiltration indicate that the lytic agents form large aggregates or macromolecular complexes.
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Affiliation(s)
- Haiyan Ma
- Alfred Wegener Institute for Polar and Maine Research, Am Handelshafen 12, Bremerhaven, Germany.
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