DOCSLIB.ORG

Cellular and Molecular Mechanisms of Biomineralisation in a Silicifying Haptophyte Prymnesium Neolepis

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Cellular and Molecular Mechanisms of Biomineralisation in a Silicifying Haptophyte Prymnesium Neolepis University of Plymouth PEARL https://pearl.plymouth.ac.uk 04 University of Plymouth Research Theses 01 Research Theses Main Collection 2014 CELLULAR AND MOLECULAR MECHANISMS OF BIOMINERALISATION IN A SILICIFYING HAPTOPHYTE PRYMNESIUM NEOLEPIS Durak, Grazyna http://hdl.handle.net/10026.1/3098 Plymouth University All content in PEARL is protected by copyright law. Author manuscripts are made available in accordance with publisher policies. Please cite only the published version using the details provided on the item record or document. In the absence of an open licence (e.g. Creative Commons), permissions for further reuse of content should be sought from the publisher or author. CELLULAR AND MOLECULAR MECHANISMS OF BIOMINERALISATION IN A SILICIFYING HAPTOPHYTE PRYMNESIUM NEOLEPIS by GRAŻYNA MAŁGORZATA DURAK A thesis submitted to the University of Plymouth in partial fulfilment for the degree of DOCTOR OF PHILOSOPHY School of Marine Science & Engineering Faculty of Science & Technology In collaboration with The Marine Biological Association of the United Kingdom -August 2013- -1- Copyright Statement This copy of the thesis has been supplied on condition that anyone who consults it is understood to recognise that its copyright rests with its author and that no quotation from the thesis and no information derived from it may be published without the author's prior consent. -2- Grażyna Małgorzata Durak ABSTRACT CELLULAR AND MOLECULAR MECHANISMS OF BIOMINERALISATION IN A SILICIFYING HAPTOPHYTE PRYMNESIUM NEOLEPIS Haptophytes are renowned for the most prominent and biogeochemically important group of marine calcifiers: coccolithophores. The unexpected discovery of a unique, silicifying member of this clade - Prymnesium neolepis - prompted questions regarding mechanisms of silicification and their origin in the calcifier-dominated haptophytes. To address these questions I used cell physiology, biochemistry and molecular approaches, investigating cellular and molecular mechanisms involved in silicification in haptophytes. Comparisons of this system with calcification in coccolithophores and other silica-based systems in eukaryotes were also made. Here I report that P. neolepis is an obligate silicifier, producing silica scales in a process fundamentally different to that observed in coccolithophores. Scale deposition and secretion in P. neolepis is localized in the posterior, vacuolar part of the cell rather than in the anterior part near the flagellar roots as in calcifying coccolithophores. The organic matrix underlying silica scales in P. neolepis was found to be non-homologous with organic scales, which in coccolithophores serve as coccolith baseplates. This suggests, that silica scales and coccoliths arise from two distinct, most likely non-homologous processes, which is further supported by the comparative investigation of the role of cytoskeleton in silica scale production in P. neolepis and coccolithogenesis in a representative calcifier, Coccolithus pelagicus. Using cytoskeleton inhibitors I established, that the cytoskeleton components used for morphogenesis and secretion of biomineralised structures are different in these two systems. Analysis of P. neolepis biosilica revealed the presence of an intimately associated organic fraction consisting of a putatively chitin-containing material, potentially serving as an organic matrix underlying silica scales. Further biochemical investigation of the biosilica-associated organics confirmed the presence of long chain polyamines (LCPAs) dissimilar to those previously reported in diatoms and sponges. Additionally, a potentially novel, proline and lysine-rich protein sharing a weak homology with lipocalins was recovered, suggesting that this silicification system is unique to haptophytes. Several theories concerning acquisition of the ability to silicify in haptophytes were proposed. Overall, the findings presented in this study provide a detailed description of Si biomineralisation system in this unique, silicifying haptophyte and supply novel information on biomineralisation systems in marine haptophytes. This study contributes a basis on which the phenomenon of silicification in haptophytes can be further investigated, as well as novel information which can be further used in elucidation of origins of silicification in algae and other Eucarya. -3- LIST OF CONTENTS PAGE ABSTRACT .................................................................................................................... 3 LIST OF FIGURES AND TABLES ................................................................................... 11 LIST OF ABBREVIATIONS ............................................................................................. 17 ACKNOWLEDGEMENTS ............................................................................................... 20 AUTHOR'S DECLARATION .................................................................................. 21 CHAPTER I: METABOLISM AND PHYSIOLOGY OF SILICON. MECHANISMS AND FUNCTIONS OF BIOMINERALISATION IN DIFFERENT PHYLA ....................................... 23 I.1. INTRODUCTION ..................................................................................................... 23 I.2. ALGAE: SILICA ..................................................................................................... 26 I.3. DIATOMS (HETEROKONTOPHYTA: BACILLARIOPHYCEAE) ................................... 27 I.3.1. Cell cycle ....................................................................................................... 27 I.3.2. Transport and storage .................................................................................... 28 I.3.3. Si Uptake and transport models ...................................................................... 29 I.3.4. Valve formation: SDV .................................................................................... 33 I.3.5. Components involved in silica polymerization ................................................ 34 I.3.6. Organic matrix of the frustule ........................................................................ 36 I.3.7. Polyanionic polysaccharides .......................................................................... 38 I.4. CHRYSOPHYTES .................................................................................................... 38 I.5. HAPTOPHYTES (HAPTOHPYTA: COCCOLITHOPHYCEAE) ...................................... 39 I.5.1. Coccolithales and Isochrysidales: calcification............................................. 40 I.5.1.1. Heterococcolith formation ........................................................................... 40 I.5.I.2. Holococcolith formation .............................................................................. 43 I.5.2. Prymnesiales: Prymnesium neolepis: silicification in haptophytes ............... 44 I.6. SPONGES (PORIFERA) ........................................................................................... 45 -4- I.6.1. Spicule formation ........................................................................................... 46 I.6.2. Silicateins ...................................................................................................... 50 I.6.3. Silicase .......................................................................................................... 52 I.6.4. Silintaphins .................................................................................................... 53 I.6.5. Long chain polyamines................................................................................... 54 I.7. PLANTS ................................................................................................................. 54 I.7.1. Si transporters ............................................................................................... 55 I.8. SUMMARY AND AIMS ............................................................................................ 56 CHAPTER II: PRYMNESIUM NEOLEPIS: GENERAL ORGANISM DESCRIPTION, BIOLOGY AND PHYSIOLOGY OF SILICIFICATION ........................................................................ 59 II.1. INTRODUCTION ................................................................................................... 59 II.1.1. Putative capacity for silicification in Prymnesium sp. ................................... 61 II.2. METHODS ........................................................................................................... 63 II.2.1. Culture conditions ........................................................................................ 63 II.2.2. DNA extraction, gene amplification, sequencing and molecular analysis ...... 64 II.2.3. Confocal microscopy .................................................................................... 66 II.2.4. Differential Interference Contrast (DIC)/light microscopy imaging............... 67 II.2.5. NaOH etching of biosilica material ............................................................... 67 II.2.6. Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and Energy Dispersive Microanalysis (EDX) ............................................... 68 II.2.7. Fourier Transform Infrared Spectroscopy (FTIR) ......................................... 68 II.2.8. Light: dark experiment: flow cytometry assessment of silica scale production ............................................................................................................................... 69 II.2.9. High/Low Si experiment ...............................................................................
Load more

Recommended publications
  • University of Oklahoma
    UNIVERSITY OF OKLAHOMA GRADUATE COLLEGE MACRONUTRIENTS SHAPE MICROBIAL COMMUNITIES, GENE EXPRESSION AND PROTEIN EVOLUTION A DISSERTATION SUBMITTED TO THE GRADUATE FACULTY in partial fulfillment of the requirements for the Degree of DOCTOR OF PHILOSOPHY By JOSHUA THOMAS COOPER Norman, Oklahoma 2017 MACRONUTRIENTS SHAPE MICROBIAL COMMUNITIES, GENE EXPRESSION AND PROTEIN EVOLUTION A DISSERTATION APPROVED FOR THE DEPARTMENT OF MICROBIOLOGY AND PLANT BIOLOGY BY ______________________________ Dr. Boris Wawrik, Chair ______________________________ Dr. J. Phil Gibson ______________________________ Dr. Anne K. Dunn ______________________________ Dr. John Paul Masly ______________________________ Dr. K. David Hambright ii © Copyright by JOSHUA THOMAS COOPER 2017 All Rights Reserved. iii Acknowledgments I would like to thank my two advisors Dr. Boris Wawrik and Dr. J. Phil Gibson for helping me become a better scientist and better educator. I would also like to thank my committee members Dr. Anne K. Dunn, Dr. K. David Hambright, and Dr. J.P. Masly for providing valuable inputs that lead me to carefully consider my research questions. I would also like to thank Dr. J.P. Masly for the opportunity to coauthor a book chapter on the speciation of diatoms. It is still such a privilege that you believed in me and my crazy diatom ideas to form a concise chapter in addition to learn your style of writing has been a benefit to my professional development. I’m also thankful for my first undergraduate research mentor, Dr. Miriam Steinitz-Kannan, now retired from Northern Kentucky University, who was the first to show the amazing wonders of pond scum. Who knew that studying diatoms and algae as an undergraduate would lead me all the way to a Ph.D.
    [Show full text]
  • Harmful Algae 91 (2020) 101587
    Harmful Algae 91 (2020) 101587 Contents lists available at ScienceDirect Harmful Algae journal homepage: www.elsevier.com/locate/hal Review Progress and promise of omics for predicting the impacts of climate change T on harmful algal blooms Gwenn M.M. Hennona,c,*, Sonya T. Dyhrmana,b,* a Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY, United States b Department of Earth and Environmental Sciences, Columbia University, New York, NY, United States c College of Fisheries and Ocean Sciences University of Alaska Fairbanks Fairbanks, AK, United States ARTICLE INFO ABSTRACT Keywords: Climate change is predicted to increase the severity and prevalence of harmful algal blooms (HABs). In the past Genomics twenty years, omics techniques such as genomics, transcriptomics, proteomics and metabolomics have trans- Transcriptomics formed that data landscape of many fields including the study of HABs. Advances in technology have facilitated Proteomics the creation of many publicly available omics datasets that are complementary and shed new light on the Metabolomics mechanisms of HAB formation and toxin production. Genomics have been used to reveal differences in toxicity Climate change and nutritional requirements, while transcriptomics and proteomics have been used to explore HAB species Phytoplankton Harmful algae responses to environmental stressors, and metabolomics can reveal mechanisms of allelopathy and toxicity. In Cyanobacteria this review, we explore how omics data may be leveraged to improve predictions of how climate change will impact HAB dynamics. We also highlight important gaps in our knowledge of HAB prediction, which include swimming behaviors, microbial interactions and evolution that can be addressed by future studies with omics tools. Lastly, we discuss approaches to incorporate current omics datasets into predictive numerical models that may enhance HAB prediction in a changing world.
    [Show full text]
  • Biology and Systematics of Heterokont and Haptophyte Algae1
    American Journal of Botany 91(10): 1508±1522. 2004. BIOLOGY AND SYSTEMATICS OF HETEROKONT AND HAPTOPHYTE ALGAE1 ROBERT A. ANDERSEN Bigelow Laboratory for Ocean Sciences, P.O. Box 475, West Boothbay Harbor, Maine 04575 USA In this paper, I review what is currently known of phylogenetic relationships of heterokont and haptophyte algae. Heterokont algae are a monophyletic group that is classi®ed into 17 classes and represents a diverse group of marine, freshwater, and terrestrial algae. Classes are distinguished by morphology, chloroplast pigments, ultrastructural features, and gene sequence data. Electron microscopy and molecular biology have contributed signi®cantly to our understanding of their evolutionary relationships, but even today class relationships are poorly understood. Haptophyte algae are a second monophyletic group that consists of two classes of predominately marine phytoplankton. The closest relatives of the haptophytes are currently unknown, but recent evidence indicates they may be part of a large assemblage (chromalveolates) that includes heterokont algae and other stramenopiles, alveolates, and cryptophytes. Heter- okont and haptophyte algae are important primary producers in aquatic habitats, and they are probably the primary carbon source for petroleum products (crude oil, natural gas). Key words: chromalveolate; chromist; chromophyte; ¯agella; phylogeny; stramenopile; tree of life. Heterokont algae are a monophyletic group that includes all (Phaeophyceae) by Linnaeus (1753), and shortly thereafter, photosynthetic organisms with tripartite tubular hairs on the microscopic chrysophytes (currently 5 Oikomonas, Anthophy- mature ¯agellum (discussed later; also see Wetherbee et al., sa) were described by MuÈller (1773, 1786). The history of 1988, for de®nitions of mature and immature ¯agella), as well heterokont algae was recently discussed in detail (Andersen, as some nonphotosynthetic relatives and some that have sec- 2004), and four distinct periods were identi®ed.
    [Show full text]
  • The Coccolithophore Family Calciosoleniaceae with Report of A
    The coccolithophore family Calciosoleniaceae with report of a new species: Calciosolenia subtropicus from the southern Indian Ocean Shramik Patil, Rahul Mohan, Syed Jafar, Sahina Gazi, Pallavi Choudhari, Xavier Crosta To cite this version: Shramik Patil, Rahul Mohan, Syed Jafar, Sahina Gazi, Pallavi Choudhari, et al.. The coccolithophore family Calciosoleniaceae with report of a new species: Calciosolenia subtropicus from the southern Indian Ocean. Micropaleontology, Micropaleontology Press, 2019. hal-02323185 HAL Id: hal-02323185 https://hal.archives-ouvertes.fr/hal-02323185 Submitted on 22 Oct 2019 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. The coccolithophore family Calciosoleniaceae with report of a new species: Calciosolenia subtropicus from the southern Indian Ocean Shramik Patil1, Rahul Mohan1, Syed A. Jafar2, Sahina Gazi1, Pallavi Choudhari1 and Xavier Crosta3 1National Centre for Polar and Ocean Research (NCPOR), Headland Sada, Vasco-da-Gama, Goa-403804, India email: [email protected] 2Flat 5-B, Whispering Meadows, Haralur Road, Bangalore-560 102, India 3UMR-CNRS 5805 EPOC, Université de Bordeaux, Allée Geoffroy Saint Hilaire, 33615 Pessac Cedex, France ABSTRACT: The families Calciosoleniaceae, Syracosphaeraceae and Rhabdosphaeraceae belong to the order Syracosphaerales and constitute a significant component of extant coccolithophore species, sharing similar ultrastructural bauplans.
    [Show full text]
  • Within-Arctic Horizontal Gene Transfer As a Driver of Convergent Evolution in Distantly Related 1 Microalgae 2 Richard G. Do
    bioRxiv preprint doi: https://doi.org/10.1101/2021.07.31.454568; this version posted August 2, 2021. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. 1 Within-Arctic horizontal gene transfer as a driver of convergent evolution in distantly related 2 microalgae 3 Richard G. Dorrell*+1,2, Alan Kuo3*, Zoltan Füssy4, Elisabeth Richardson5,6, Asaf Salamov3, Nikola 4 Zarevski,1,2,7 Nastasia J. Freyria8, Federico M. Ibarbalz1,2,9, Jerry Jenkins3,10, Juan Jose Pierella 5 Karlusich1,2, Andrei Stecca Steindorff3, Robyn E. Edgar8, Lori Handley10, Kathleen Lail3, Anna Lipzen3, 6 Vincent Lombard11, John McFarlane5, Charlotte Nef1,2, Anna M.G. Novák Vanclová1,2, Yi Peng3, Chris 7 Plott10, Marianne Potvin8, Fabio Rocha Jimenez Vieira1,2, Kerrie Barry3, Joel B. Dacks5, Colomban de 8 Vargas2,12, Bernard Henrissat11,13, Eric Pelletier2,14, Jeremy Schmutz3,10, Patrick Wincker2,14, Chris 9 Bowler1,2, Igor V. Grigoriev3,15, and Connie Lovejoy+8 10 11 1 Institut de Biologie de l'ENS (IBENS), Département de Biologie, École Normale Supérieure, CNRS, 12 INSERM, Université PSL, 75005 Paris, France 13 2CNRS Research Federation for the study of Global Ocean Systems Ecology and Evolution, 14 FR2022/Tara Oceans GOSEE, 3 rue Michel-Ange, 75016 Paris, France 15 3 US Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, 1 16 Cyclotron Road, Berkeley,
    [Show full text]
  • Literature Review of the Microalga Prymnesium Parvum and Its Associated Toxicity
    Literature Review of the Microalga Prymnesium parvum and its Associated Toxicity Sean Watson, Texas Parks and Wildlife Department, August 2001 Introduction Recent large-scale fish kills associated with the golden-alga, Prymnesium parvum, have imposed monetary and ecological losses on the state of Texas. This phytoflagellate has been implicated in fish kills around the world since the 1930’s (Reichenbach-Klinke 1973). Kills due to P. parvum blooms are normally accompanied by water with a golden-yellow coloration that foams in riffles (Rhodes and Hubbs 1992). The factors responsible for the appearance of toxic P. parvum blooms have yet to be determined. The purpose of this paper is to present a review of the work by those around the globe whom have worked with Prymnesium parvum in an attempt to better understand the biology and ecology of this organism as well as its associated toxicity. I will concentrate on the relevant biology important in the ecology and identification of this organism, its occurrence, nutritional requirements, factors governing its toxicity, and methods used to control toxic blooms with which it is associated. Background Biology and Diagnostic Features Prymnesium parvum is a microalga in the class Prymnesiophyceae, order Prymnesiales and family Prymnesiaceae, and is a common member of the marine phytoplankton (Bold and Wynne 1985, Larsen 1999, Lee 1980). It is a uninucleate, unicellular flagellate with an ellipsoid or narrowly oval cell shape (Lee 1980, Prescott 1968). Green, Hibberd and Pienaar (1982) reported that the cells range from 8-11 micrometers long and 4-6 micrometers wide. The authors also noted that the cells are PWD RP T3200-1158 (8/01) 2 Lit.
    [Show full text]
  • Observations on Syracosphaera Rhombica Sp. Nov
    Disponible en ligne sur ScienceDirect www.sciencedirect.com Revue de micropaléontologie 59 (2016) 233–237 Coccolithophores in modern oceans Observations on Syracosphaera rhombica sp. nov. Observations sur Syracosphaera rhombica sp. nov. a b c,∗ Harald Andruleit , Aisha Ejura Agbali , Richard W. Jordan a Bundesanstalt für Geowissenschaften und Rohstoffe (BGR), Stilleweg 2, 30655 Hannover, Germany b Earth, Ocean and Atmospheric Science, Florida State University, P.O. Box 3064520, Tallahassee, FL 32306-4520, USA c Department of Earth & Environmental Sciences, Faculty of Science, Yamagata University, 1-4-12 Kojirakawa-machi, Yamagata 990-8560, Japan Abstract A spherical coccosphere and two collapsed coccospheres composed of monomorphic rhombic coccoliths were encountered in 2005 in the Java upwelling system of the SE Indian Ocean, while a further two specimens with elongate coccospheres were recently found in the Gulf of Mexico. All of the specimens were collected from the lower photic zone (75–160 m). The coccoliths possess a proximal flange, a slightly flared wall with a serrated distal margin, and a relatively plain central area structure comprised only of overlapping laths. The taxon appears to be an undescribed species of the Syracosphaera nodosa group, so we describe it herein as Syracosphaera rhombica sp. nov. © 2016 Published by Elsevier Masson SAS. Keywords: Coccolithophorid; Gulf of Mexico; Indian Ocean; Lower photic zone; Syracosphaera Résumé Une coccosphère sphérique (ainsi que deux coccosphères effondrées) composée de coccolithes rhombiques monomorphiques a été rencontrée en 2005 dans le système de remontée d’eaux profondes de Java dans l’océan Indien du Sud-Est, tandis que deux autres spécimens avec coccosphères allongées ont été récemment trouvées dans le golfe du Mexique.
    [Show full text]
  • Phylogeny, Life History, Autecology and Toxicity of Prymnesium Parvum
    Phylogeny, life history, autecology and toxicity of Prymnesium parvum Bente Edvardsen1,2 and Aud Larsen3 1 University of Oslo, Norway, 2 NIVA, Norway 3 University of Bergen, Norway Distribution of Prymnesium parvum record bloom s s Overview • morphology - what it looks like • phylogeny - how is P. parvum related to other organisms • life cycle – with alternating cell types • physiology - nutrition and toxicity • autecology - growth as a function of environmental factors • occurrence of P. parvum - interpreting environmental conditions that cause blooms • how can we reduce the risk for harmful blooms? Division: Haptophyta Class: Prymnesiophyceae Species: Prymnesium parvum forms: f. parvum and f. patelliferum Morphology of P. parvum haptonema flagella chloroplast Ill.: Jahn Throndsen Photos: Wenche Eikrem scales A Light micrograph of cell B Electron micrograph of scales Organic scales covering the cells - character for species identification inside outside (Larsen 1998) Prymnesium species Species Habitat Distribution Toxic P. parvum brackish worldwide, temperate yes zone P. annuliferum marine France (Med. Sea) unknown P. calathiferum marine New Zealand yes P. faveolatum marine France, Spain yes P. nemamethecum marine S Africa, Australia unknown P. zebrinum marine France (Med. Sea) unknown P. czosnowskii, P. gladiociliatum, P. minutum, P.papillarum and P. saltans have uncertain status Haptophyte phylogeny 100/100 Pavlova aff. salina 87/57 Pavlova gyrans Pavlova CCMP1416 99/100 Pavlova CCMP 1394 Phaeocystis sp. 1 100/100 OLI51004 99/ Phaeocystis
    [Show full text]
  • Integrative Taxonomy of the Pavlovophyceae (Haptophyta): a Reassessment
    Protist, Vol. 162, 738–761, November 2011 http://www.elsevier.de/protis Published online date 28 June 2011 ORIGINAL PAPER Integrative Taxonomy of the Pavlovophyceae (Haptophyta): A Reassessment El Mahdi Bendifa,b,1, Ian Proberta,2, Annie Hervéc, Chantal Billardb, Didier Gouxd, Christophe Lelongb, Jean-Paul Cadoretc, and Benoît Vérona,b,3 aUniversité de Caen Basse-Normandie, Algobank-Caen, IFR 146, 14032 Caen, France bUniversité de Caen Basse-Normandie, UMR 100 PE2 M - IFREMER, 14032 Caen, France cIFREMER, Laboratoire de Physiologie et Biotechnologie des Algues, rue de l’Ile d’Yeu, BP21105, 44311 Nantes, France dUniversité de Caen Basse-Normandie, Centre de Microscopie Appliquée à la Biologie, IFR 146, 14032 Caen, France Submitted October 18, 2010; Accepted March 15, 2011 Monitoring Editor: Barry S. C. Leadbeater. The Pavlovophyceae (Haptophyta) contains four genera (Pavlova, Diacronema, Exanthemachrysis and Rebecca) and only thirteen characterised species, several of which are important in ecological and eco- nomic contexts. We have constructed molecular phylogenies inferred from sequencing of ribosomal gene markers with comprehensive coverage of the described diversity, using type strains when avail- able, together with additional cultured strains. The morphology and ultrastructure of 12 of the described species was also re-examined and the pigment signatures of many culture strains were determined. The molecular analysis revealed that sequences of all described species differed, although those of Pavlova gyrans and P. pinguis were nearly identical, these potentially forming a single cryptic species complex. Four well-delineated genetic clades were identified, one of which included species of both Pavlova and Diacronema. Unique combinations of morphological/ultrastructural characters were iden- tified for each of these clades.
    [Show full text]
  • A Sea of Lilliputians
    1 5/27/08 A Sea of Lilliputians by Marie-Pierre Aubry Department of Earth and Planetary Sciences Rutgers University 610 Taylor Road, Piscataway, New Jersey 08854-8066 and Department of Geology and Geophysics Woods Hole Oceanographic Institution Woods Hole Ma 02543 Fax: 732 445 3374, [email protected] Abstract Smaller size is generally seen as a negative response of organisms to stressful environmental conditions, associated with low diversity and species dominance. The mean size of the coccolithophorids decreased through the Neogene, leading to the prediction that their extant representatives are characterized by poor diversification and low specialization. The study of the (exo)coccospheres of selected taxa in the order Syracosphaerales negates this prediction, revealing that on the contrary some extant lineages are highly diversified and remarkably specialized. Whereas the general role of coccoliths remains indeterminate, this analysis suggests that some highly derived coccoliths may be modified for the collection of food particles, including picoplankton, thus implying that mixotrophy may characterize these lineages. In the extant coccolithophorids, species richness of genera is inversely correlated with the size of cells, definitive evidence that small size is part of a morphologic strategy rather than a sign of evolutionary failure. Because of their extreme minuteness, the extant nannoplankton can be well compared to Lilliputians, but the trend toward size decrease in Neogene lineages is not attributable to the Lilliput effect described by Urbanek (1993). 2 5/27/08 Key words: Extant coccolithophorids, Neogene, size, exococcospheres, functional morphology, mixotrophy. 1. Introduction Cope’s law, which in its broadest concept states that the size of organisms increases as lineages diversify, is generally regarded as prevalent among organisms despite a considerable debate as to its significance (e.g., Stanley, 1973, Gould, 1997, Jablonski, 1997, Alroy, 1998, Trammer, 2002).
    [Show full text]
  • Transcriptomic Response of the Toxic Prymnesiophyte Prymnesium Parvum
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Electronic Publication Information Center Harmful Algae 18 (2012) 1–15 Contents lists available at SciVerse ScienceDirect Harmful Algae jo urnal homepage: www.elsevier.com/locate/hal Transcriptomic response of the toxic prymnesiophyte Prymnesium parvum (N. Carter) to phosphorus and nitrogen starvation a, a,b,1 a,1 a c,d Sa´ra Beszteri *, Ines Yang , Nina Jaeckisch , Urban Tillmann , Stephan Frickenhaus , e a a Gernot Glo¨ckner , Allan Cembella , Uwe John a Department of Ecological Chemistry, Alfred Wegener Institute for Polar and Marine Research, Am Handelshafen 12, 27568 Bremerhaven, Germany b Institute of Medical Microbiology and Hospital Epidemiology, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany c Computing centre/Bioinformatics, Alfred Wegener Institute for Polar and Marine Research, Am Handelshafen 12, 27568 Bremerhaven, Germany d Hochschule Bremerhaven, An der Karlstadt 8, 27568 Bremerhaven, Germany e Leibniz-Institute of Freshwater Ecology and Inland Fisheries, IGB, Mu¨ggelseedamm 301, D-12587 Berlin, Germany A R T I C L E I N F O A B S T R A C T Article history: The ichthyotoxic and mixotrophic prymnesiophyte Prymnesium parvum is known to produce dense Received 23 August 2011 virtually monospecific blooms in marine coastal, brackish, and inshore waters. Fish-killing Pyrmnesium Received in revised form 6 March 2012 blooms are often associated with macronutrient imbalanced conditions based upon shifts in ambient Accepted 6 March 2012 nitrogen (N):phosphorus (P) ratios. We therefore investigated nutrient-dependent cellular acclimation Available online 30 March 2012 mechanisms of this microalga based upon construction of a normalized expressed sequence tag (EST) library.
    [Show full text]
  • A 15 Million-Year Long Record of Phenotypic Evolution in the Heavily Calcified Coccolithophore Helicosphaera and Its Biogeochemical Implications
    A 15 million-year long record of phenotypic evolution in the heavily calcified coccolithophore Helicosphaera and its biogeochemical implications 5 Luka Šupraha1, a, Jorijntje Henderiks1, 2 1 Department of Earth Sciences, Uppsala University, Villavägen 16, SE-752 36 Uppsala, Sweden. 2 Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biosciences, University of Oslo, P.O. Box 1066 Blindern, 0316 Oslo, Norway. a Present address: Section for Aquatic Biology and Toxicology (AQUA), Department of Biosciences, University of Oslo, P.O. 10 Box 1066 Blindern, 0316 Oslo, Norway Correspondence to: Luka Šupraha ([email protected]) Abstract. The biogeochemical impact of coccolithophores is defined by their overall abundance in the oceans, but also by a wide range in physiological traits such as cell size, degree of calcification and carbon production rates between different species. Species’ “sensitivity” to environmental forcing has been suggested to relate to their cellular PIC:POC ratio and other 15 physiological constraints. Understanding both the short and longer-term adaptive strategies of different coccolithophore lineages, and how these in turn shape the biogeochemical role of the group, is therefore crucial for modeling the ongoing changes in the global carbon cycle. Here we present data on the phenotypic evolution of a large and heavily-calcified genus Helicosphaera (order Zygodiscales) over the past 15 million years (Ma), at two deep-sea drill sites from the tropical Indian Ocean and temperate South Atlantic. The modern species Helicosphaera carteri, which displays eco-physiological adaptations 20 in modern strains, was used to benchmark the use of its coccolith morphology as a physiological proxy in the fossil record.
    [Show full text]