DOCSLIB.ORG

The Protozoa, a Kingdom by Default?

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
The Protozoa, a Kingdom by Default? A Kingdom By Default? WILL H. BLACKWELL MARTHAJ. POWELL Those Many Kingdoms A Thumbnail on Protozoology Downloaded from http://online.ucpress.edu/abt/article-pdf/63/7/483/50291/4451168.pdf by guest on 02 October 2021 A good start to a revaluationof the Protozoa is a hanges in concepts of kingdoms of brief look at some main events in the history of study organisms over the latter 20th century of the group, especially in North America. We can have been substantial (Blackwell & Powell here venture the bottom line first. If we span the 1999), sometimes tedious, yet with the worthy goal course of protozoology during the 20th century, we of establishing groupings of organisms reflective of eventually arrive at two apparently contradictory major evolutionarylineages. An increasing number of conclusions: (1) the classification of no group we kingdoms is recognized, typically including two have recognized as a phylum, subkingdom or king- prokaryotic kingdoms, Archaea(Archaebacteria) and dom has changed more, (2) nor has the classification Bacteria(Woese et al. 1990), and six or more eukary- of any group ultimately come more full-circle. otic kingdoms: Protozoa (the amitochondrial mem- Perhaps these seemingly disparate points will be bers sometimes separated as kingdom Archezoa), clear by the end of our discussion. Chromista (including the major group, Stramenopiles), Biliphyta, Plantae, Fungi, and The first major textbook on protozoology in the Animalia (cf. Cavalier-Smith 1987; Corliss 1994; United States, The Protozoa, by Gary N. Calkins Blackwell& Powell 1995). Still more kingdoms have (1901) of Columbia University, probably had more been suggested; Leedale (1974), for example, out- impact in this field of study than any other single lined as many as 19 kingdoms among scenarios he work. Seemingly heedless of the three-kingdom discussed. approach of Haeckel (1866), who proposed a unicel- lular kingdom, Protista, Calkins (1901) followed the Difficulty is encountered in seeking an exclusive Linnaeanview of life as divisible along plant and ani- definition of several of these kingdoms. In particular, mal lines. He recognized the phylum Protozoa as an the Protozoa is loosely characterized;its membership apparently definable group, i.e. unicellular organ- is decided partially by the fact of not belonging to isms, within the otherwise multicellular kingdom another kingdom (Cox 1991; Cavalier-Smith1993). Animalia. But since Protozoa are, in a selection of recent litera- ture, referred to as a kingdom (e.g. Cavalier-Smith Calkins'system of four fundamentalclasses with- 1993; Blackwell& Powell 1995; Beakes 1998; Corliss in the phylum Protozoa-Mastigophora (flagellates), 1994, 1998; Vickerman 1998), it is of possible bene- Sarcodina (amoebae), Infusoria (ciliates), and fit to teachers of biology to reassess the characteriza- Sporozoa (gregarines,coccidea)-remains influential tion, confines and membership of this potential king- (a basis for our proposition of the "full-circle"arrival dom of organisms. of knowledge in protozoology). With minor changes, Calkins' system was echoed in works on Protozoa (and in the "protozoan section" in general works of zoology) through the first half of the 20th century. WILLH. BLACKWELLis an AdjunctProfessor and MARTHAAJ.POWELL For example, R. P. Hall (1953), of New York is Professorand Chair of the Departmentof BiologicalSciences at University,produced an excellent survey of Protozoa, the Universityof Alabama, Tuscaloosa,AL 35487-0344. titled "Protozoology";Hall employed the traditional, THEPROTOZOA, AKINGDOM BYDEFAULT? 483 locomotion-based,light microscopic charactersof some authors (e.g. Levine et al. 1980), but not others Protozoaestablished by Calkins,adding additional (e.g. Jahn et al. 1979). In more recent classifications informationgained during the 50 years following (e.g. Cox 1991; Sleigh 1991), formal headings for Calkins'original text (1901). For reference,we pres- major protozoan groups were often dropped. ent the outlineof Hall'ssystem (Table 1), representa- tiveof mid-century,traditional protozoological classi- Recognition of the Protista; fication.But, changes were in the offing.Questioning the ultimate divisibilityof amoeboid and flagellate Obscuring of the Protozoa protozoans,Honigberg et al. (1964) combinedthese as "Sarcomastigophora'-amodification followed by Having seemingly forgotten, for a hundred years, Haeckel's (1866) proposal for a king- dom Protista,realization reoccurred that a number of unicellular organisms, e.g. TABLE 1. Euglena, dinoflagellates, chrysamoebas, Groups of Protozoa, Hall 1953._ cryptomonads, are not readily fitted into plant and animal kingdoms. As a conse- Downloaded from http://online.ucpress.edu/abt/article-pdf/63/7/483/50291/4451168.pdf by guest on 02 October 2021 Subphylum1.Mastigophora Subclass3.Haemosporidia quence, the kingdom Protista was again Class1. Phytomastigophorea Class2. Cnidosporidea invoked (e.g. Whittaker 1969). With this "rebirth"of Protista came a similar Order1.Chrysomonadida Order1.Myxosporida realizationthat fungal organisms are nei- Order2.Heterochlorida Order2.Actinomyxida ther plant nor animal, and the kingdom Order3.Cryptomonadida Order3.Microsporida Fungi was also established. Whittaker's Order4.Dinoflagellida Order4.Helicosporida five-kingdomproposal - Monera (bacte- OrderS.Phytomonadida Class3. Acnidosporidea ria, prokaryotes), Protista (unicellular Order6.Euglenida Subclass1.Sarcosporidia eukaryotes), Plantae, Animalia and Fungi - pervaded texts of biology for Order7.Chloromonadida Subclass2.Haplosporidia two decades, and is still occasionally Class2. Zoomastigophorea Subphylum4.Ciliophora advocated. Whittaker (1969), and later Order1.Rhizomastigida Class1. Ciliatea Margulis(1974, 1981), who preferenced Order2.Protomastigida Subclass1.Protociliatia the name Protoctista over Protista, are Order3.Polymastigida Order1.Opalinida associated with the development of the Order4.Trichomonadida Subclass2.Euciliatia five-kingdomconcept; however, the core of this proposal (and a suggested addi- Order5.Hypermastigida Order1.Holotrichida tional kingdom for viruses) appeared in Subphylum2.Sarcodina Suborder1.Astomina Jahn and Jahn's (1949) "How to Know Class1. Actinopodea Suborder2.Gymnostomina the Protozoa." Order1.Helioflagellida Suborder3.Trichostomina What did establishment of the Order2.Heliozoida Suborder4.Hymenostomina five-kingdom system mean to the recog- Order3.Radiolarida Suborder5.Thigmotrichina nition and classification of Protozoa?At Class2. Rhizopodea Suborder6.Apostomina first it simply implied a transfer of the Order1.Proteomyxida Order2.Spirotrichida unicellular phylum (or subkingdom) Protozoa from the multicellular king- Order2.Mycetozoida Suborder1.Heterotrichina dom, Animalia, to the unicellular-based Order3.Amoebida Suborder2.Tintinnina kingdom Protista (e.g. Jahn et al. 1979). Order4.Testacida Suborder3.Oligotrichina However, delimitation of Protozoa soon Order5.Foraminiferida Suborder4. Entodiniomorphina blurred amid the taxonomic melange of Subphylum3.Sporozoa Suborder5.Hypotrichina the inflated kingdom Protista. John Corliss' (1981) paper, "Whatare the tax- Suborder6.Ctenostomina Class1.Telosporidea onomic and evolutionary relationships Order3.Peritrichida Subclass1.Gregarinidia of the Protozoa to the Protista?,"went to Order1.Eugregarinida Order4.Chonotrichida the heart of this issue. This question of Order2.Schizogregarinida Class 2. Suctorea protozoan, and other protist group, Subclass2.Coccidia identities was again voiced by Corliss 484 THEAMERICAN BIOLOGY TEACHER, VOLUME 63, NO.7,SEPTEMBER 2001 (1983) in a paper titled, perhaps tongue-in-cheek,"A nonetheless continue to be recognized in some Puddle of Protists." recent biology texts (e.g. Johnson 2000). Corliss raised a two-partedissue: Purging the Protista; 1. The kingdom Protistawas too large, too inclu- sive, too polyphyletic (a largely unnatural Reemergence of the Protozoa 45 phyla assemblage). Corliss (1984) listed The solution to an identity dilemma (i.e. what under Protista, with more to come. The "uni- does/does not constitute Protista?)lies in acquisition in Protista cellular criterion"for "membership" of knowledge. An advance was Cavalier-Smith's was compromised by inclusion of predomi- (1986, 1989) recognition of the kingdom Chromista. brown nantly multicellular groups, such as The largest assemblage within the Chromista is phy- algae (Phaeophyta) and red algae lum Heterokonta,a name referringto unequal flagel- (Rhodophyta). la of many of its members; the more forwardof these 2. Distinctions of formal, major taxonomic flagella generally bears tubular (2- or, more often, mastigonemes (flagellarhairs). In reference groups within the Protistawere vanishing. 3-parted) Downloaded from http://online.ucpress.edu/abt/article-pdf/63/7/483/50291/4451168.pdf by guest on 02 October 2021 to these mastigonemes, Patterson (1989) gave this Given this breakdown of protistan macrosystem- natural heterokont assemblage the appropriate,but atic infrastructure, Corliss (1981) recognized five informal, name Stramenopiles ("straw hairs"). informalgroupings of protist phyla:(1) the protozoan Stramenopila, more monophyletic than Chromista, group;(2) the protozoalgalgroup; (3) the algal group; has been suggested as a candidate kingdom (e.g. (4) the protozofungalgroup; and (5) the fungalgroup, Campbell et al. 1999). for "fungalprotists," not for the kingdom Fungi. Photosynthetic Stramenopiles typicallypossess a The Protistabecame an unwieldy colossus, hous- "chloroplast endoplasmic
Load more

Recommended publications
  • Red Algae (Bangia Atropurpurea) Ecological Risk Screening Summary
    Red Algae (Bangia atropurpurea) Ecological Risk Screening Summary U.S. Fish & Wildlife Service, February 2014 Revised, March 2016, September 2017, October 2017 Web Version, 6/25/2018 1 Native Range and Status in the United States Native Range From NOAA and USGS (2016): “Bangia atropurpurea has a widespread amphi-Atlantic range, which includes the Atlantic coast of North America […]” Status in the United States From Mills et al. (1991): “This filamentous red alga native to the Atlantic Coast was observed in Lake Erie in 1964 (Lin and Blum 1977). After this sighting, records for Lake Ontario (Damann 1979), Lake Michigan (Weik 1977), Lake Simcoe (Jackson 1985) and Lake Huron (Sheath 1987) were reported. It has become a major species of the littoral flora of these lakes, generally occupying the littoral zone with Cladophora and Ulothrix (Blum 1982). Earliest records of this algae in the basin, however, go back to the 1940s when Smith and Moyle (1944) found the alga in Lake Superior tributaries. Matthews (1932) found the alga in Quaker Run in the Allegheny drainage basin. Smith and 1 Moyle’s records must have not resulted in spreading populations since the alga was not known in Lake Superior as of 1987. Kishler and Taft (1970) were the most recent workers to refer to the records of Smith and Moyle (1944) and Matthews (1932).” From NOAA and USGS (2016): “Established where recorded except in Lake Superior. The distribution in Lake Simcoe is limited (Jackson 1985).” From Kipp et al. (2017): “Bangia atropurpurea was first recorded from Lake Erie in 1964. During the 1960s–1980s, it was recorded from Lake Huron, Lake Michigan, Lake Ontario, and Lake Simcoe (part of the Lake Ontario drainage).
    [Show full text]
  • The Global Dispersal of the Non-Endemic Invasive Red Alga Gracilariavermiculophylla in the Ecosystems of the Euro-Asia Coastal W
    Review Article Oceanogr Fish Open Access J Volume 8 Issue 1 - July 2018 Copyright © All rights are reserved by Vincent van Ginneken DOI: 10.19080/OFOAJ.2018.08.555727 The Global Dispersal of the Non-Endemic Invasive Red Alga Gracilaria vermiculophylla in the Ecosystems of the Euro-Asia Coastal Waters Including the Wadden Sea Unesco World Heritage Coastal Area: Awful or Awesome? Vincent van Ginneken* and Evert de Vries Bluegreentechnologies, Heelsum, Netherlands Submission: September 05, 2017; Published: July 06, 2018 Corresponding author: Vincent van Ginneken, Bluegreentechnologies, Heelsum, Netherlands, Email: Abstract Gracilaria vermiculophylla (Ohmi) Papenfu ß 1967 (Rhodophyta, Gracilariaceae) is a red alga and was originally described in Japan in 1956 as Gracilariopsis vermiculophylla G. vermiculophylla is primarily used as a precursor for agar, which is widely used in the pharmaceutical and food industries. It has been introduced to the East . It is thought to be native and widespread throughout the Northwest Pacific Ocean. temperature) and can grow in an extremely wide variety of conditions; factors which contribute to its invasiveness. It invades estuarine areas Pacific, the West Atlantic and the East Atlantic, where it rapidly colonizes new environments. It is highly tolerant of stresses (nutrient, salinity, invaded: Atlantic, North Sea, Mediterranean and Baltic Sea. The Euro-Asian brackish Black-Sea have not yet been invaded but are very vulnerable towhere intense it out-competes invasion with native G. vermiculophylla algae species and modifies environments. The following European coastal and brackish water seas are already G. vermiculophylla among the most potent invaders out of 114 non-indigenous because they macro-algae are isolated species from indirect Europe.
    [Show full text]
  • Number of Living Species in Australia and the World
    Numbers of Living Species in Australia and the World 2nd edition Arthur D. Chapman Australian Biodiversity Information Services australia’s nature Toowoomba, Australia there is more still to be discovered… Report for the Australian Biological Resources Study Canberra, Australia September 2009 CONTENTS Foreword 1 Insecta (insects) 23 Plants 43 Viruses 59 Arachnida Magnoliophyta (flowering plants) 43 Protoctista (mainly Introduction 2 (spiders, scorpions, etc) 26 Gymnosperms (Coniferophyta, Protozoa—others included Executive Summary 6 Pycnogonida (sea spiders) 28 Cycadophyta, Gnetophyta under fungi, algae, Myriapoda and Ginkgophyta) 45 Chromista, etc) 60 Detailed discussion by Group 12 (millipedes, centipedes) 29 Ferns and Allies 46 Chordates 13 Acknowledgements 63 Crustacea (crabs, lobsters, etc) 31 Bryophyta Mammalia (mammals) 13 Onychophora (velvet worms) 32 (mosses, liverworts, hornworts) 47 References 66 Aves (birds) 14 Hexapoda (proturans, springtails) 33 Plant Algae (including green Reptilia (reptiles) 15 Mollusca (molluscs, shellfish) 34 algae, red algae, glaucophytes) 49 Amphibia (frogs, etc) 16 Annelida (segmented worms) 35 Fungi 51 Pisces (fishes including Nematoda Fungi (excluding taxa Chondrichthyes and (nematodes, roundworms) 36 treated under Chromista Osteichthyes) 17 and Protoctista) 51 Acanthocephala Agnatha (hagfish, (thorny-headed worms) 37 Lichen-forming fungi 53 lampreys, slime eels) 18 Platyhelminthes (flat worms) 38 Others 54 Cephalochordata (lancelets) 19 Cnidaria (jellyfish, Prokaryota (Bacteria Tunicata or Urochordata sea anenomes, corals) 39 [Monera] of previous report) 54 (sea squirts, doliolids, salps) 20 Porifera (sponges) 40 Cyanophyta (Cyanobacteria) 55 Invertebrates 21 Other Invertebrates 41 Chromista (including some Hemichordata (hemichordates) 21 species previously included Echinodermata (starfish, under either algae or fungi) 56 sea cucumbers, etc) 22 FOREWORD In Australia and around the world, biodiversity is under huge Harnessing core science and knowledge bases, like and growing pressure.
    [Show full text]
  • Protist Phylogeny and the High-Level Classification of Protozoa
    Europ. J. Protistol. 39, 338–348 (2003) © Urban & Fischer Verlag http://www.urbanfischer.de/journals/ejp Protist phylogeny and the high-level classification of Protozoa Thomas Cavalier-Smith Department of Zoology, University of Oxford, South Parks Road, Oxford, OX1 3PS, UK; E-mail: [email protected] Received 1 September 2003; 29 September 2003. Accepted: 29 September 2003 Protist large-scale phylogeny is briefly reviewed and a revised higher classification of the kingdom Pro- tozoa into 11 phyla presented. Complementary gene fusions reveal a fundamental bifurcation among eu- karyotes between two major clades: the ancestrally uniciliate (often unicentriolar) unikonts and the an- cestrally biciliate bikonts, which undergo ciliary transformation by converting a younger anterior cilium into a dissimilar older posterior cilium. Unikonts comprise the ancestrally unikont protozoan phylum Amoebozoa and the opisthokonts (kingdom Animalia, phylum Choanozoa, their sisters or ancestors; and kingdom Fungi). They share a derived triple-gene fusion, absent from bikonts. Bikonts contrastingly share a derived gene fusion between dihydrofolate reductase and thymidylate synthase and include plants and all other protists, comprising the protozoan infrakingdoms Rhizaria [phyla Cercozoa and Re- taria (Radiozoa, Foraminifera)] and Excavata (phyla Loukozoa, Metamonada, Euglenozoa, Percolozoa), plus the kingdom Plantae [Viridaeplantae, Rhodophyta (sisters); Glaucophyta], the chromalveolate clade, and the protozoan phylum Apusozoa (Thecomonadea, Diphylleida). Chromalveolates comprise kingdom Chromista (Cryptista, Heterokonta, Haptophyta) and the protozoan infrakingdom Alveolata [phyla Cilio- phora and Miozoa (= Protalveolata, Dinozoa, Apicomplexa)], which diverged from a common ancestor that enslaved a red alga and evolved novel plastid protein-targeting machinery via the host rough ER and the enslaved algal plasma membrane (periplastid membrane).
    [Show full text]
  • Using Diatom and Apicomplexan Models to Study the Heme Pathway of Chromera Velia
    International Journal of Molecular Sciences Article Using Diatom and Apicomplexan Models to Study the Heme Pathway of Chromera velia Jitka Richtová 1,2, Lilach Sheiner 3 , Ansgar Gruber 1 , Shun-Min Yang 1,2 , LudˇekKoˇrený 4, Boris Striepen 5 and Miroslav Oborník 1,2,* 1 Biology Centre CAS, Laboratory of Evolutionary Protistology, Institute of Parasitology, 370 05 Ceskˇ é Budˇejovice,Czech Republic; [email protected] (J.R.); [email protected] (A.G.); [email protected] (S.-M.Y.) 2 Faculty of Science, University of South Bohemia, 370 05 Ceskˇ é Budˇejovice,Czech Republic 3 Welcome Centre for Integrative Parasitology, College of Medical, Veterinary and Life Sciences, Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow G12 8QQ, UK; [email protected] 4 Department of Biochemistry, University of Cambridge, Cambridge CB2 1TN, UK; [email protected] 5 Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; [email protected] * Correspondence: [email protected]; Tel.: +420-387-775-464 Abstract: Heme biosynthesis is essential for almost all living organisms. Despite its conserved function, the pathway’s enzymes can be located in a remarkable diversity of cellular compartments in different organisms. This location does not always reflect their evolutionary origins, as might be expected from the history of their acquisition through endosymbiosis. Instead, the final subcellular localization of the enzyme reflects multiple factors, including evolutionary origin, demand for the product, availability of the substrate, and mechanism of pathway regulation. The biosynthesis of Citation: Richtová, J.; Sheiner, L.; heme in the apicomonad Chromera velia follows a chimeric pathway combining heme elements from Gruber, A.; Yang, S.-M.; Koˇrený,L.; the ancient algal symbiont and the host.
    [Show full text]
  • Signal Conflicts in the Phylogeny of the Primary Photosynthetic
    Signal Conflicts in the Phylogeny of the Primary Photosynthetic Eukaryotes Philippe Deschamps and David Moreira Unite´ d’Ecologie, Syste´matique et Evolution, UMR CNRS 8079, Universite Paris-Sud 11, Orsay Cedex, France It is widely accepted that the first photosynthetic eukaryotes arose from a single primary endosymbiosis of a cyanobacterium in a phagotrophic eukaryotic host, which led to the emergence of three major lineages: Chloroplastida (green algae and land plants), Rhodophyta, and Glaucophyta. For a long time, Glaucophyta have been thought to represent the earliest branch among them. However, recent massive phylogenomic analyses of nuclear genes have challenged this view, because most of them suggested a basal position of Rhodophyta, though with moderate statistical support. We have addressed this question by phylogenomic analysis of a large data set of 124 proteins transferred from the chloroplast to the nuclear genome of the three Archaeplastida lineages. In contrast to previous analyses, we found strong support for the basal emergence of the Chloroplastida and the sister-group relationship of Glaucophyta and Rhodophyta. Moreover, the reanalysis of chloroplast gene sequences using methods more robust against compositional and evolutionary rate biases sustained the same result. Finally, we observed that the basal position of Rhodophyta found in the phylogenies based on nuclear genes depended on the sampling of sequences used as outgroup. When eukaryotes supposed to have never had plastids (animals and fungi) were used, the analysis strongly supported the early emergence of Glaucophyta instead of Rhodophyta. Therefore, there is a conflicting signal between genes of different evolutionary origins supporting either the basal branching of Glaucophyta or of Chloroplastida within the Archaeplastida.
    [Show full text]
  • The Fungi Belonging to Kingdom Chromista: A. Oomycota
    The Fungi belonging to Kingdom Chromista: a. Oomycota: Dr. Basudha Sharma Chromista ► Wittaker divided living beings into 5-Kingdom-Monera (Prokaryotic), Protista (Eukaryotic), Fungi, Plantae and Animalia. Molecular phylogeny, however suggested a new division: Chromista ► The chromists represent an independent evolutionary lineage that appears to have diverged from the same common ancestor as plants, animals and fungi. ► Chromista means ‘coloured’ and includes some colourless chromists like oomycota and certain algae. ► they all possess flagellated cells at some stage of their life cycles, and the flagella are typically of two types-hetrokont (whiplash and tinsel) ► the chloroplast is bounded by a double membrane, but has an extra layer of ER (also two-layered) that is often continuous with the nuclear envelope Chromista Oomycota ► commonly known as water moulds ► some are unicellular, however majority are multicellular and mycelial (branched filamentous coenocyte) ► They are classified as chromists because their free-swimming zoospores possess the heterokont-type flagella also, reserve food is stored in the form of mycolaminarin, an energy storage molecule similar to that found in diatoms and brown algae. ► oomycetes cell walls are composed of cellulose, free-living stage of the oomycetes has a diploid chromosome complement while that of the fungi is haploid. ► Asexual reproduction is by biflagellate zoospores ► Sexual reproduction is oogamus and involves the formation of oogonia and antheridia Saprolegnia ► These fungi are saprophytic organisms that are widely distributed in the aquatic environment and can derive nutrients from any organic source in water ► They become pathogenic to fish only when fish are stressed or eg. diseased. They attach to surfaces like gills and fins of fishes ► Reproduction in Saprolegnia may be sexual or asexual.
    [Show full text]
  • Kenai National Wildlife Refuge Species List, Version 2018-07-24
    Kenai National Wildlife Refuge Species List, version 2018-07-24 Kenai National Wildlife Refuge biology staff July 24, 2018 2 Cover image: map of 16,213 georeferenced occurrence records included in the checklist. Contents Contents 3 Introduction 5 Purpose............................................................ 5 About the list......................................................... 5 Acknowledgments....................................................... 5 Native species 7 Vertebrates .......................................................... 7 Invertebrates ......................................................... 55 Vascular Plants........................................................ 91 Bryophytes ..........................................................164 Other Plants .........................................................171 Chromista...........................................................171 Fungi .............................................................173 Protozoans ..........................................................186 Non-native species 187 Vertebrates ..........................................................187 Invertebrates .........................................................187 Vascular Plants........................................................190 Extirpated species 207 Vertebrates ..........................................................207 Vascular Plants........................................................207 Change log 211 References 213 Index 215 3 Introduction Purpose to avoid implying
    [Show full text]
  • New Phylogenomic Analysis of the Enigmatic Phylum Telonemia Further Resolves the Eukaryote Tree of Life
    bioRxiv preprint doi: https://doi.org/10.1101/403329; this version posted August 30, 2018. 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. New phylogenomic analysis of the enigmatic phylum Telonemia further resolves the eukaryote tree of life Jürgen F. H. Strassert1, Mahwash Jamy1, Alexander P. Mylnikov2, Denis V. Tikhonenkov2, Fabien Burki1,* 1Department of Organismal Biology, Program in Systematic Biology, Uppsala University, Uppsala, Sweden 2Institute for Biology of Inland Waters, Russian Academy of Sciences, Borok, Yaroslavl Region, Russia *Corresponding author: E-mail: [email protected] Keywords: TSAR, Telonemia, phylogenomics, eukaryotes, tree of life, protists bioRxiv preprint doi: https://doi.org/10.1101/403329; this version posted August 30, 2018. 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. Abstract The broad-scale tree of eukaryotes is constantly improving, but the evolutionary origin of several major groups remains unknown. Resolving the phylogenetic position of these ‘orphan’ groups is important, especially those that originated early in evolution, because they represent missing evolutionary links between established groups. Telonemia is one such orphan taxon for which little is known. The group is composed of molecularly diverse biflagellated protists, often prevalent although not abundant in aquatic environments.
    [Show full text]
  • The IUCN Red List of Threatened Speciestm
    Species 2014 Annual ReportSpecies the Species of 2014 Survival Commission and the Global Species Programme Species ISSUE 56 2014 Annual Report of the Species Survival Commission and the Global Species Programme • 2014 Spotlight on High-level Interventions IUCN SSC • IUCN Red List at 50 • Specialist Group Reports Ethiopian Wolf (Canis simensis), Endangered. © Martin Harvey Muhammad Yazid Muhammad © Amazing Species: Bleeding Toad The Bleeding Toad, Leptophryne cruentata, is listed as Critically Endangered on The IUCN Red List of Threatened SpeciesTM. It is endemic to West Java, Indonesia, specifically around Mount Gede, Mount Pangaro and south of Sukabumi. The Bleeding Toad’s scientific name, cruentata, is from the Latin word meaning “bleeding” because of the frog’s overall reddish-purple appearance and blood-red and yellow marbling on its back. Geographical range The population declined drastically after the eruption of Mount Galunggung in 1987. It is Knowledge believed that other declining factors may be habitat alteration, loss, and fragmentation. Experts Although the lethal chytrid fungus, responsible for devastating declines (and possible Get Involved extinctions) in amphibian populations globally, has not been recorded in this area, the sudden decline in a creekside population is reminiscent of declines in similar amphibian species due to the presence of this pathogen. Only one individual Bleeding Toad was sighted from 1990 to 2003. Part of the range of Bleeding Toad is located in Gunung Gede Pangrango National Park. Future conservation actions should include population surveys and possible captive breeding plans. The production of the IUCN Red List of Threatened Species™ is made possible through the IUCN Red List Partnership.
    [Show full text]
  • Protists – a Textbook Example for a Paraphyletic Taxon
    ARTICLE IN PRESS Organisms, Diversity & Evolution 7 (2007) 166–172 www.elsevier.de/ode Protists – A textbook example for a paraphyletic taxon$ Martin Schlegela,Ã, Norbert Hu¨lsmannb aInstitute for Biology II, University of Leipzig, Talstraße 33, 04103 Leipzig, Germany bFree University of Berlin, Institute of Biology/Zoology, Working group Protozoology, Ko¨nigin-Luise-Straße 1-3, 14195 Berlin, Germany Received 7 September 2004; accepted 21 November 2006 Abstract Protists constitute a paraphyletic taxon since the latter is based on the plesiomorphic character of unicellularity and does not contain all descendants of the stem species. Multicellularity evolved several times independently in metazoans, higher fungi, heterokonts, red and green algae. Various hypotheses have been developed on the evolution and nature of the eukaryotic cell, considering the accumulating data on the chimeric nature of the eukaryote genome. Subsequent evolution of the protists was further complicated by primary, secondary, and even tertiary intertaxonic recombinations. However, multi-gene sequence comparisons and structural data point to a managable number of such events. Several putative monophyletic lineages and a gross picture of eukaryote phylogeny are emerging on the basis of those data. The Chromalveolata comprise Chromista and Alveolata (Dinoflagellata, Apicomplexa, Ciliophora, Perkinsozoa, and Haplospora). Major lineages of the former ‘amoebae’ group within the Heterolobosa, Cercozoa, and Amoebozoa. Cercozoa, including filose testate amoebae, chlorarachnids, and plasmodiophoreans seem to be affiliated with foraminiferans. Amoebozoa consistently form the sister group of the Opisthokonta (including fungi, and with choanoflagellates as sister group of metazoans). A clade of ‘plants’ comprises glaucocystophytes, red algae, green algae, and land vascular plants. The controversial debate on the root of the eukaryote tree has been accelerated by the interpretation of gene fusions as apomorphic characters.
    [Show full text]
  • Proposal for Practical Multi-Kingdom Classification of Eukaryotes Based on Monophyly 2 and Comparable Divergence Time Criteria
    bioRxiv preprint doi: https://doi.org/10.1101/240929; this version posted December 29, 2017. 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 4.0 International license. 1 Proposal for practical multi-kingdom classification of eukaryotes based on monophyly 2 and comparable divergence time criteria 3 Leho Tedersoo 4 Natural History Museum, University of Tartu, 14a Ravila, 50411 Tartu, Estonia 5 Contact: email: [email protected], tel: +372 56654986, twitter: @tedersoo 6 7 Key words: Taxonomy, Eukaryotes, subdomain, phylum, phylogenetic classification, 8 monophyletic groups, divergence time 9 Summary 10 Much of the ecological, taxonomic and biodiversity research relies on understanding of 11 phylogenetic relationships among organisms. There are multiple available classification 12 systems that all suffer from differences in naming, incompleteness, presence of multiple non- 13 monophyletic entities and poor correspondence of divergence times. These issues render 14 taxonomic comparisons across the main groups of eukaryotes and all life in general difficult 15 at best. By using the monophyly criterion, roughly comparable time of divergence and 16 information from multiple phylogenetic reconstructions, I propose an alternative 17 classification system for the domain Eukarya to improve hierarchical taxonomical 18 comparability for animals, plants, fungi and multiple protist groups. Following this rationale, 19 I propose 32 kingdoms of eukaryotes that are treated in 10 subdomains. These kingdoms are 20 further separated into 43, 115, 140 and 353 taxa at the level of subkingdom, phylum, 21 subphylum and class, respectively (http://dx.doi.org/10.15156/BIO/587483).
    [Show full text]