DOCSLIB.ORG

Coordinated Beating of Algal Flagella Is Mediated by Basal Coupling Kirsty Y

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Coordinated Beating of Algal Flagella Is Mediated by Basal Coupling Kirsty Y i i “coupling100316˙full” — 2016/3/10 — 18:12 — page 1 — #1 i i Coordinated Beating of Algal Flagella is Mediated by Basal Coupling Kirsty Y. Wan ∗ and Raymond E. Goldstein ∗ ∗Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Wilberforce Road, Cambridge CB3 0WA, UK Submitted to Proceedings of the National Academy of Sciences of the United States of America Cilia and flagella often exhibit synchronized behavior; this includes (VC) is perhaps the smallest colonial organism to exhibit cellular divi- phase-locking, as seen in Chlamydomonas, and metachronal wave sion of labor (13). Adult spheroids possess two cell types: large germ formation in the respiratory cilia of higher organisms. Since the ob- cells interior of an extracellular matrix grow to form new colonies, servations by Gray and Rothschild of phase synchrony of nearby swim- while smaller somatic cells form a dense surface covering of flag- ming spermatozoa, it has been a working hypothesis that synchrony ella protruding into the medium, enabling swimming. These flag- arises from hydrodynamic interactions between beating filaments. Recent work on the dynamics of physically separated pairs of flagella ella generate waves of propulsion which despite lack of centralized isolated from the multicellular alga Volvox has shown that hydrody- or neuronal control (“coxless”) are coherent over the span of the or- namic coupling alone is sufficient to produce synchrony. However, ganism (14). In addition, somatic cells isolated from their embedding the situation is more complex in unicellular organisms bearing few colonies (Fig. 1A) beat their flagella in synchrony when held suf- flagella. We show that flagella of Chlamydomonas mutants deficient ficiently close to each other (12). Pairwise configurations of these in filamentary connections between basal bodies display markedly dif- flagella tend to synchronize in-phase (IP) when oriented with power ferent synchronization from the wildtype. We perform micromanip- strokes in the same direction, but antiphase (AP) when oriented in ulation on configurations of flagella and conclude that a mechanism, opposite directions, as predicted (15) if their mutual interaction were internal to the cell, must provide an additional flagellar coupling. hydrodynamic. Yet, not all flagellar coordination observed in unicel- In naturally-occurring species with 4, 8 or even 16 flagella, we find diverse symmetries of basal-body positioning and of the flagellar ap- lular organisms can be explained thus. The lineage to which Volvox paratus that are coincident with specific gaits of flagellar actuation, belongs includes the common ancestor of the alga Chlamydomonas suggesting that it is a competition between intracellular coupling reinhardtii (CR) (Fig. 1B), which swims with a familiar in-phase and hydrodynamic interactions that ultimately determines the pre- breaststroke with twin flagella that are developmentally positioned cise form of flagellar coordination in unicellular algae. to beat in opposite directions (Fig. 1C,D). Yet, a Chlamydomonas mutant with dysfunctional phototaxis switches stochastically the ac- Chlorophyte j Prasinophyte j eukaryotic algae j internal cou- tuation of its flagella between IP and AP modes (15, 16). These ob- pling j flagellar synchronization j basal fibers servations led us to conjecture (15) that a mechanism, internal to the cell, must function to overcome hydrodynamic effects. Pairs of interacting flagella evoke no image more potent than Huy- Significance Statement gens’ clocks (17): two oscillating pendula may tend towards syn- In areas as diverse as developmental biology, physiology and chrony (or anti-synchrony) if attached to a common support, whose biomimetics there is great interest in understanding the mechanisms flexibility providing the necessary coupling. Here we present a di- by which active hair-like cellular appendages known as flagella or verse body of evidence for existence of a biophysical equivalent to cilia are brought into coordinated motion. The prevailing theoret- this mechanical coupling, which in CR and related algae we propose ical hypothesis over many years is that fluid flows driven by beat- is provided ultrastructurally by prominent fibers connecting pairs of ing flagella provide the coupling that leads to synchronization, but basal bodies (BB) (18) that are known to have contractile proper- this is surprisingly inconsistent with certain experimentally observed ties. Such filamentary connections are absent in configurations of two phenomena. Here we demonstrate the insufficiency of hydrodynamic pipette-held uniflagellate cells and defective in a class of CR mutants coupling in an evolutionarily significant range of unicellular algal known as vfl (Fig. 1B). We show in both cases that the synchroniza- species bearing multiple flagella, and suggest the key additional in- tion states are markedly different from the wildtype breaststroke. gredient for precise coordination of flagellar beating is provided by Seeking evidence for the generality of putative internal control of contractile fibers of the basal apparatus. flagellar coupling in algal unicells, we use light microscopy, high- speed imaging and image-processing to elucidate the remarkable co- ordination strategies adopted by quadri-, octo-, and hexadecaflagel- Introduction lates, which possess networks of basal, interflagellar linkages that ossession of multiple cilia and flagella bestows significant evo- increase in complexity with flagella number. The flagellar appara- Plutionary advantage upon living organisms only if these or- tus, comprising BBs, connecting fibers, microtubular rootlets and the ganelles can achieve coordination. This may be for purposes of swim- transition regions of axonemes, is among the most biochemically and ming (1, 2), feeding (3), or fluid transport (4, 5). Multiciliation may morphologically complex structures occurring in eukaryotic flagel- have evolved first in single-celled microorganisms due to the propen- sity for hydrodynamic interactions to couple their motions, but was retained in higher organisms, occurring in such places as the murine Reserved for Publication Footnotes brain (6) or human airway epithelia (7). Since Sir James Gray first noted that “automatic units” of flagella beat in “an orderly sequence” when placed side by side (8), others have observed the tendency for nearby sperm cells to undulate in unison or aggregate (9, 10), and subsequently the possible hydrodynamic origins of this phenomenon have been the subject of extensive theoretical analyses (2, 5, 11). De- spite this, the exclusiveness and universality of hydrodynamic effects in the coordination of neighboring cilia and flagella remains unclear. We begin by considering one context in which hydrodynamic in- teractions are sufficient for synchrony (12). The alga Volvox carteri www.pnas.org/cgi/doi/10.1073/pnas.0709640104 PNAS Issue Date Volume Issue Number 1{16 i i i i i i “coupling100316˙full” — 2016/3/10 — 18:12 — page 2 — #2 i i 2+ multicellular IP AP ing to differential flagellar responses. Ionic fluctuations (e.g. Ca ) cis alter not only the flagellar beat, but also the synchrony of a pair. BB Gait changes involving transient loss of synchrony (called ’slips’), 5 µm occur stochastically at rates sensitive to such environmental factors (15, 27, 34) as temperature, light, chemicals, hydrodynamics, and 1. parallel 2. anti-parallel trans BB age of cell culture. In free-swimming cells, slips can alter the balance of hydrodynamic drag on the cell body, producing a rocking motion V. carteri that promotes subsequent resynchrony of flagella (31), but this does not explain the robust IP synchrony in cells held immobilized on mi- cropipettes (16, 29), nor the motility of isolated and reactivated flag- ellar apparatuses (35). The altered beat during slips is analogous to cis BB the freestyle gait (AP in Fig. 1) characterized in the phototaxis mu- unicellular tant ptx1, which stochastically transitions between IP and AP gaits (15, 16). The dependence of CR flagellar synchronization state on physiology through temperature or ionic content of the medium (27) leads us now to the possibility for intracellular coupling of flagella. 5 µm Early work (18) identified thick fibers connecting the two Chlamy- or 3 C. reinhardtii domonas BBs, including a 300×250×75 nm bilaterally symmetric trans BB distal fiber (DF), bearing complex striation patterns with a periodic- no robust IP synchrony ity of ∼ 80 nm (Fig. 1B). Striation periodicity varies across species, Fig. 1: Flagellar synchronization in multi- vs uni- cellular algae. A) Pairs and is changeable by chemical stimuli – indicating active contractility of isolated, somatic flagella of V. carteri (VC) tend to synchronize either in (36). The DF contains centrin, also found in NBBCs (Fig. 1B) which in-phase (IP) or anti-phase (AP) depending on their relative orientation. B) C. are involved in localization of BBs during cell division (37). The two reinhardtii (CR) flagella maintain position 2 yet swims a robust IP breaststroke BBs have an identical structure of 9 triplet microtubules which form that is lost i) by mutation of the distal fiber (DF), and ii) in pairs of nearby uni- a cartwheel arrangement (38). Importantly, the DF lies in the plane flagellate cells. C+D) Ultrastructure comprising basal bodies (BBs), rootlets, of flagellar beating, and furthermore attaches to each BB at the same and eyespot in VC and CR. [PF - proximal fiber(s); NBBC - nuclear-basal- body connectors; t1 − 9: numbered microtubule triplets.] site relative to the beating
Load more

Recommended publications
  • Sexual Selection in Fungi
    Sexual selection in Fungi Bart P. S. Nieuwenhuis Thesis committee Thesis supervisor Prof. dr. R.F. Hoekstra Emeritus professor of Genetics (Population and Quantitative Genetics) Wageningen University Thesis co-supervisor Dr. D.K. Aanen Assistant professor at the Laboratory of Genetics Wageningen University Other members Prof. dr. J. B. Anderson, University of Toronto, Toronto, Canada Prof. dr. W. de Boer, NIOO, Wageningen and Wageningen University Prof. dr. P.G.L. Klinkhamer, Leiden University, Leiden Prof. dr. H.A.B. Wösten, Utrecht Univesity, Utrecht This research was conducted under the auspices of the C.T. de Wit Graduate School for Production Ecology and Resource Conservation (PE&RC) Sexual selection in Fungi Bart P. S. Nieuwenhuis Thesis submittted in fulfilment of the requirements for the degree of doctor at Wageningen University by the authority of the Rector Magnificus Prof. dr. M.J. Kropff, in the presence of the Thesis Committee appointed by the Academic Board to be defended in public on Friday 21 September 2012 at 4 p.m. in the Aula. Bart P. S. Nieuwenhuis Sexual selection in Fungi Thesis, Wageningen University, Wageningen, NL (2012) With references, with summaries in Dutch and English ISBN 978-94-6173-358-0 Contents Chapter 1 7 General introduction Chapter 2 17 Why mating types are not sexes Chapter 3 31 On the asymmetry of mating in the mushroom fungus Schizophyllum commune Chapter 4 49 Sexual selection in mushroom-forming basidiomycetes Chapter 5 59 Fungal fidelity: Nuclear divorce from a dikaryon by mating or monokaryon regeneration Chapter 6 69 Fungal nuclear arms race: experimental evolution for increased masculinity in a mushroom Chapter 7 89 Sexual selection in the fungal kingdom Chapter 8 109 Discussion: male and female fitness Bibliography 121 Summary 133 Dutch summary 137 Dankwoord 147 Curriculum vitea 153 Education statement 155 6 Chapter 1 General introduction Bart P.
    [Show full text]
  • Why Mushrooms Have Evolved to Be So Promiscuous: Insights from Evolutionary and Ecological Patterns
    fungal biology reviews 29 (2015) 167e178 journal homepage: www.elsevier.com/locate/fbr Review Why mushrooms have evolved to be so promiscuous: Insights from evolutionary and ecological patterns Timothy Y. JAMES* Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109, USA article info abstract Article history: Agaricomycetes, the mushrooms, are considered to have a promiscuous mating system, Received 27 May 2015 because most populations have a large number of mating types. This diversity of mating Received in revised form types ensures a high outcrossing efficiency, the probability of encountering a compatible 17 October 2015 mate when mating at random, because nearly every homokaryotic genotype is compatible Accepted 23 October 2015 with every other. Here I summarize the data from mating type surveys and genetic analysis of mating type loci and ask what evolutionary and ecological factors have promoted pro- Keywords: miscuity. Outcrossing efficiency is equally high in both bipolar and tetrapolar species Genomic conflict with a median value of 0.967 in Agaricomycetes. The sessile nature of the homokaryotic Homeodomain mycelium coupled with frequent long distance dispersal could account for selection favor- Outbreeding potential ing a high outcrossing efficiency as opportunities for choosing mates may be minimal. Pheromone receptor Consistent with a role of mating type in mediating cytoplasmic-nuclear genomic conflict, Agaricomycetes have evolved away from a haploid yeast phase towards hyphal fusions that display reciprocal nuclear migration after mating rather than cytoplasmic fusion. Importantly, the evolution of this mating behavior is precisely timed with the onset of diversification of mating type alleles at the pheromone/receptor mating type loci that are known to control reciprocal nuclear migration during mating.
    [Show full text]
  • By Thesis for the Degree of Doctor of Philosophy
    COMPARATIVE ANATOMY AND HISTOCHEMISTRY OF TIIE ASSOCIATION OF PUCCIiVIA POARUM WITH ITS ALTERNATE HOSTS By TALIB aWAID AL-KHESRAJI Department of Botany~ Universiiy of SheffieZd Thesis for the degree of Doctor of Philosophy JUNE 1981 Vol 1 IMAGING SERVICES NORTH Boston Spa, Wetherby West Yorkshire, lS23 7BQ www.bl.uk BEST COpy AVAILABLE. VARIABLE PRINT QUALITY TO MY PARENTS i Ca.1PARATIVE ANATCl1Y AND HISTOCHEMISTRY OF THE ASSOCIATION OF PUCCINIA POARUM WITH ITS ALTERNATE HOSTS Talib Owaid Al-Khesraji Depaptment of Botany, Univepsity of Sheffield The relationship of the macrocyclic rust fungus PUccinia poarum with its pycnial-aecial host, Tussilago fapfaPa, and its uredial-telial host, Poa ppatensis, has been investigated, using light microscopy, electron microscopy and micro-autoradiography. Aspects of the morp­ hology and ontogeny of spores and sari, which were previously disputed, have been clarified. Monokaryotic hyphae grow more densely in the intercellular spaces of Tussilago leaves than the dikaryotic intercellular hyphae on Poa. Although ultrastructurally sbnilar, monokaryotic hyphae differ from dikaryotic hyphae in their interaction with host cell walls, often growing embedded in wall material which may project into the host cells. The frequency of penetration of Poa mesophyll cells by haustoria of the dikaryon is greater than that of Tussilago cells by the relatively undifferentiated intracellular hyphae of the monokaryon. Intracellular hyphae differ from haustoria in their irregular growth, septation, lack of a neck-band or markedly constricted neck, the deposition of host wall-like material in the external matrix bounded by the invaginated host plasmalemma and in the association of callose reactions \vith intracellular hyphae and adjacent parts of host walls.
    [Show full text]
  • Perspectives in Phycology Vol
    Perspectives in Phycology Vol. 3 (2016), Issue 3, p. 141–154 Article Published online June 2016 Diversity and ecology of green microalgae in marine systems: an overview based on 18S rRNA gene sequences Margot Tragin1, Adriana Lopes dos Santos1, Richard Christen2,3 and Daniel Vaulot1* 1 Sorbonne Universités, UPMC Univ Paris 06, CNRS, UMR 7144, Station Biologique, Place Georges Teissier, 29680 Roscoff, France 2 CNRS, UMR 7138, Systématique Adaptation Evolution, Parc Valrose, BP71. F06108 Nice cedex 02, France 3 Université de Nice-Sophia Antipolis, UMR 7138, Systématique Adaptation Evolution, Parc Valrose, BP71. F06108 Nice cedex 02, France * Corresponding author: [email protected] With 5 figures in the text and an electronic supplement Abstract: Green algae (Chlorophyta) are an important group of microalgae whose diversity and ecological importance in marine systems has been little studied. In this review, we first present an overview of Chlorophyta taxonomy and detail the most important groups from the marine environment. Then, using public 18S rRNA Chlorophyta sequences from culture and natural samples retrieved from the annotated Protist Ribosomal Reference (PR²) database, we illustrate the distribution of different green algal lineages in the oceans. The largest group of sequences belongs to the class Mamiellophyceae and in particular to the three genera Micromonas, Bathycoccus and Ostreococcus. These sequences originate mostly from coastal regions. Other groups with a large number of sequences include the Trebouxiophyceae, Chlorophyceae, Chlorodendrophyceae and Pyramimonadales. Some groups, such as the undescribed prasinophytes clades VII and IX, are mostly composed of environmental sequences. The 18S rRNA sequence database we assembled and validated should be useful for the analysis of metabarcode datasets acquired using next generation sequencing.
    [Show full text]
  • Phylogenetic Classification of Life
    Proc. Natl. Accad. Sci. USA Vol. 93, pp. 1071-1076, February 1996 Evolution Archaeal- eubacterial mergers in the origin of Eukarya: Phylogenetic classification of life (centriole-kinetosome DNA/Protoctista/kingdom classification/symbiogenesis/archaeprotist) LYNN MARGULIS Department of Biology, University of Massachusetts, Amherst, MA 01003-5810 Conitribluted by Lynnl Marglulis, September 15, 1995 ABSTRACT A symbiosis-based phylogeny leads to a con- these features evolved in their ancestors by inferable steps (4, sistent, useful classification system for all life. "Kingdoms" 20). rRNA gene sequences (Trichomonas, Coronympha, Giar- and "Domains" are replaced by biological names for the most dia; ref. 11) confirm these as descendants of anaerobic eu- inclusive taxa: Prokarya (bacteria) and Eukarya (symbiosis- karyotes that evolved prior to the "crown group" (12)-e.g., derived nucleated organisms). The earliest Eukarya, anaero- animals, fungi, or plants. bic mastigotes, hypothetically originated from permanent If eukaryotes began as motility symbioses between Ar- whole-cell fusion between members of Archaea (e.g., Thermo- chaea-e.g., Thermoplasma acidophilum-like and Eubacteria plasma-like organisms) and of Eubacteria (e.g., Spirochaeta- (Spirochaeta-, Spirosymplokos-, or Diplocalyx-like microbes; like organisms). Molecular biology, life-history, and fossil ref. 4) where cell-genetic integration led to the nucleus- record evidence support the reunification of bacteria as cytoskeletal system that defines eukaryotes (21)-then an Prokarya while
    [Show full text]
  • Palindromic Genes in the Linear Mitochondrial Genome of the Nonphotosynthetic Green Alga Polytomella Magna
    GBE Palindromic Genes in the Linear Mitochondrial Genome of the Nonphotosynthetic Green Alga Polytomella magna David Roy Smith1,y,JimengHua2,3,y, John M. Archibald2, and Robert W. Lee3,* 1Department of Biology, University of Western Ontario, London, Ontario, Canada 2Department of Biochemistry and Molecular Biology, Canadian Institute for Advanced Research, Integrated Microbial Biodiversity Program, Dalhousie University, Halifax, Nova Scotia, Canada 3Department of Biology, Dalhousie University, Halifax, Nova Scotia, Canada *Corresponding author: E-mail: [email protected]. yThese authors contributed equally to this work. Accepted: August 8, 2013 Data deposition: Sequence data from this article have been deposited in GenBank under the accession KC733827. Abstract Organelle DNA is no stranger to palindromic repeats. But never has a mitochondrial or plastid genome been described in which every coding region is part of a distinct palindromic unit. While sequencing the mitochondrial DNA of the nonphotosynthetic green alga Polytomella magna, we uncovered precisely this type of genic arrangement. The P. magna mitochondrial genome is linear and made up entirely of palindromes, each containing 1–7 unique coding regions. Consequently, every gene in the genome is duplicated and in an inverted orientation relative to its partner. And when these palindromic genes are folded into putative stem-loops, their predicted translational start sites are often positioned in the apex of the loop. Gel electrophoresis results support the linear, 28-kb monomeric conformation of the P. magna mitochondrial genome. Analyses of other Polytomella taxa suggest that palindromic mitochondrial genes were present in the ancestor of the Polytomella lineage and lost or retained to various degrees in extant species.
    [Show full text]
  • Permian–Triassic Non-Marine Algae of Gondwana—Distributions
    Earth-Science Reviews 212 (2021) 103382 Contents lists available at ScienceDirect Earth-Science Reviews journal homepage: www.elsevier.com/locate/earscirev Review Article Permian–Triassic non-marine algae of Gondwana—Distributions, natural T affinities and ecological implications ⁎ Chris Maysa,b, , Vivi Vajdaa, Stephen McLoughlina a Swedish Museum of Natural History, Box 50007, SE-104 05 Stockholm, Sweden b Monash University, School of Earth, Atmosphere and Environment, 9 Rainforest Walk, Clayton, VIC 3800, Australia ARTICLE INFO ABSTRACT Keywords: The abundance, diversity and extinction of non-marine algae are controlled by changes in the physical and Permian–Triassic chemical environment and community structure of continental ecosystems. We review a range of non-marine algae algae commonly found within the Permian and Triassic strata of Gondwana and highlight and discuss the non- mass extinctions marine algal abundance anomalies recorded in the immediate aftermath of the end-Permian extinction interval Gondwana (EPE; 252 Ma). We further review and contrast the marine and continental algal records of the global biotic freshwater ecology crises within the Permian–Triassic interval. Specifically, we provide a case study of 17 species (in 13 genera) palaeobiogeography from the succession spanning the EPE in the Sydney Basin, eastern Australia. The affinities and ecological im- plications of these fossil-genera are summarised, and their global Permian–Triassic palaeogeographic and stra- tigraphic distributions are collated. Most of these fossil taxa have close extant algal relatives that are most common in freshwater, brackish or terrestrial conditions, and all have recognizable affinities to groups known to produce chemically stable biopolymers that favour their preservation over long geological intervals.
    [Show full text]
  • Lateral Gene Transfer of Anion-Conducting Channelrhodopsins Between Green Algae and Giant Viruses
    bioRxiv preprint doi: https://doi.org/10.1101/2020.04.15.042127; this version posted April 23, 2020. 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 5 Lateral gene transfer of anion-conducting channelrhodopsins between green algae and giant viruses Andrey Rozenberg 1,5, Johannes Oppermann 2,5, Jonas Wietek 2,3, Rodrigo Gaston Fernandez Lahore 2, Ruth-Anne Sandaa 4, Gunnar Bratbak 4, Peter Hegemann 2,6, and Oded 10 Béjà 1,6 1Faculty of Biology, Technion - Israel Institute of Technology, Haifa 32000, Israel. 2Institute for Biology, Experimental Biophysics, Humboldt-Universität zu Berlin, Invalidenstraße 42, Berlin 10115, Germany. 3Present address: Department of Neurobiology, Weizmann 15 Institute of Science, Rehovot 7610001, Israel. 4Department of Biological Sciences, University of Bergen, N-5020 Bergen, Norway. 5These authors contributed equally: Andrey Rozenberg, Johannes Oppermann. 6These authors jointly supervised this work: Peter Hegemann, Oded Béjà. e-mail: [email protected] ; [email protected] 20 ABSTRACT Channelrhodopsins (ChRs) are algal light-gated ion channels widely used as optogenetic tools for manipulating neuronal activity 1,2. Four ChR families are currently known. Green algal 3–5 and cryptophyte 6 cation-conducting ChRs (CCRs), cryptophyte anion-conducting ChRs (ACRs) 7, and the MerMAID ChRs 8. Here we 25 report the discovery of a new family of phylogenetically distinct ChRs encoded by marine giant viruses and acquired from their unicellular green algal prasinophyte hosts.
    [Show full text]
  • Cilia and Flagella of Eukaryotes
    Cilia and Flagella of Eukaryotes I . R . GIBBONS The simple description that cilia are "contractile protoplasm in Early Developments its simplest form" (Dellinger, 1909) has fallen away as a mean- Among the most notable steps in the history of early studies ingless phrase ... A cilium is manifestly a highly complex and Downloaded from http://rupress.org/jcb/article-pdf/91/3/107s/1075481/107s.pdf by guest on 26 September 2021 compound organ, and . morphological description is clearly on cilia and flagella were the initial light microscope observa- only a beginning . tions of beating cilia on ciliated protozoa by Anton van Leeu- Irene Manton, 1952 wenhoek in 1675 ; the hypothesis proposed by W . Sharpey in 1835 that cilia and flagella are active organelles moved by contractile material distributed along their length rather than As recognized by Irene Manton (1) at the time that the basic passive structures moved by cytoplasmic flow or other contrac- 9 + 2 structural uniformity of cilia and most eukaryotic flagella tile activity within the cell body; and the observation in 1888- was first becoming recognized, these organelles are sufficiently 1890 by E . Ballowitz (2) that sperm flagella contain a substruc- complex that knowledge of their structure, no matter how ture of about 9-11 fine fibrils which are continuous along the detailed, cannot provide an understanding of their mechanisms length of the flagellum (Fig . 1) . More detailed accounts with of growth and function . In our understanding of these mecha- full references to this early work and to other studies before nisms, the substantial advances of the intervening 28 years 1948 can be found in the monographs of Sir James Gray (3) have, for the most part, resulted from experiments in which it and Michael Sleigh (4) .
    [Show full text]
  • Fungal Allergy and Pathogenicity 20130415 112934.Pdf
    Fungal Allergy and Pathogenicity Chemical Immunology Vol. 81 Series Editors Luciano Adorini, Milan Ken-ichi Arai, Tokyo Claudia Berek, Berlin Anne-Marie Schmitt-Verhulst, Marseille Basel · Freiburg · Paris · London · New York · New Delhi · Bangkok · Singapore · Tokyo · Sydney Fungal Allergy and Pathogenicity Volume Editors Michael Breitenbach, Salzburg Reto Crameri, Davos Samuel B. Lehrer, New Orleans, La. 48 figures, 11 in color and 22 tables, 2002 Basel · Freiburg · Paris · London · New York · New Delhi · Bangkok · Singapore · Tokyo · Sydney Chemical Immunology Formerly published as ‘Progress in Allergy’ (Founded 1939) Edited by Paul Kallos 1939–1988, Byron H. Waksman 1962–2002 Michael Breitenbach Professor, Department of Genetics and General Biology, University of Salzburg, Salzburg Reto Crameri Professor, Swiss Institute of Allergy and Asthma Research (SIAF), Davos Samuel B. Lehrer Professor, Clinical Immunology and Allergy, Tulane University School of Medicine, New Orleans, LA Bibliographic Indices. This publication is listed in bibliographic services, including Current Contents® and Index Medicus. Drug Dosage. The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any change in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug. All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means electronic or mechanical, including photocopying, recording, microcopy- ing, or by any information storage and retrieval system, without permission in writing from the publisher.
    [Show full text]
  • GENETIC DIVERSITY of Pyramimonas from RYUKYU ARCHIPELAGO, JAPAN (CHLOROPHYCEAE, PYRAMIMONADALES)
    Journal of Marine Science and Technology, Vol. 21, Suppl., pp. 285-296 (2013) 285 DOI: 10.6119/JMST-013-1220-16 GENETIC DIVERSITY OF Pyramimonas FROM RYUKYU ARCHIPELAGO, JAPAN (CHLOROPHYCEAE, PYRAMIMONADALES) Shoichiro Suda1, Mohammad Azmal Hossain Bhuiyan2, 1 and Daphne Georgina Faria Key words: Pyramimonas, nuclear SSU rDNA, genetic diversity, nuclear SSU rDNA ranged from 98.2% to 99.9% and 97.3% Ryukyu Archipelago. to 98.3% within and between subgenera, respectively. The present work shows high level of genetic diversity for the genus Pyramimonas from the Ryukyu Archipelago, Japan. ABSTRACT The genus Pyramimonas Schmarda was traditionally de- I. INTRODUCTION scribed on observations of its periplast and internal structure of different flagellar apparatus or eyespot orientations and The genus Pyramimonas Schmarda was first described in currently comprises of ca. 60 species that are divided into six 1850 based on P. tetrarhynchus Schmarda a freshwater species subgenera: Pyramimonas, Vestigifera, Trichocystis, Punctatae, isolated from a ditch on Coldham’s Common, Cambridge, Hexactis, and Macrura. In order to understand the genetic United Kingdom. Subsequently, species isolated were as- diversity and phylogenetic relationships of genus Pyrami- signed to several generic names, including Pyramidomonas monas members, we analyzed nuclear SSU rDNA molecular Stein, Chloraster Ehrenberg, Asteromonas Artari, and Poly- data from 41 strains isolated from different locations of the blepharides Dangeard. The genus had shown to be artificial Ryukyu Archipelago. Phylogenetic analyses revealed that as certain freshwater species were moved to the genus Haf- strains could be segregated into six clades, four of which niomonas Ettl et Moestrup. Genus Hafniomonas resembles represented existing subgenera: Pyramimonas, Vestigifera Pyramimonas in cell shape but differs with respect to lack of McFadden, Trichocystis McFadden, and Punctatae McFadden, flagellar and body scales, different cell symmetry, flagellar root, and two undescribed subgenera.
    [Show full text]
  • Nucleotide Diversity of the Colorless Green Alga Polytomella Parva (Chlorophyceae, Chlorophyta): High for the Mitochondrial Telo
    The Journal of Published by the International Society of Eukaryotic Microbiology Protistologists J. Eukaryot. Microbiol., 58(5), pp. 471–473 r 2011 The Author(s) Journal of Eukaryotic Microbiology r 2011 International Society of Protistologists DOI: 10.1111/j.1550-7408.2011.00569.x Nucleotide Diversity of the Colorless Green Alga Polytomella parva (Chlorophyceae, Chlorophyta): High for the Mitochondrial Telomeres, Surprisingly Low Everywhere Elseà DAVID ROY SMITH1 and ROBERT W. LEE Department of Biology, Dalhousie University, Halifax, Nova Scotia, Canada B3H 4R2 ABSTRACT. Silent-site nucleotide diversity data (psilent) can provide insights into the forces driving genome evolution. Here we present psilent statistics for the mitochondrial and nuclear DNAs of Polytomella parva, a nonphotosynthetic green alga with a highly reduced, linear fragmented mitochondrial genome. We show that this species harbors very little genetic diversity, with the exception of the mitochondrial telomeres, which have an excess of polymorphic sites. These data are compared with previously published psilent values from the mitochondrial and nuclear genomes of the model species Chlamydomonas reinhardtii and Volvox carteri, which are close relatives of P. parva, and are used to understand the modes and tempos of genome evolution within green algae. Key Words. Chlamydomonas, Chlorophyte, genetic diversity, mitochondrial DNA, Volvox. HE nucleotide diversity at silent sites (psilent), which include RESULTS AND DISCUSSION T noncoding positions and the synonymous sites of protein-cod- ing DNA, can provide insights into the combined contributions of For measuring nucleotide diversity we used the following Poly- genetic drift and mutation acting on a genome—parameters that are tomella SAG strains, with origins of isolation listed in brackets: SAG arguably among the key determinants driving the evolution of ge- 63-2 (Glasgow, Scotland), 63-2b (Bohemia, Czech Republic), 63-3 nomic architecture (Lynch 2007).
    [Show full text]