DOCSLIB.ORG

Oxymonads Are Closely Related to the Excavate Taxon Trimastix

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Oxymonads Are Closely Related to the Excavate Taxon Trimastix Oxymonads Are Closely Related to the Excavate Taxon Trimastix Joel B. Dacks,* Jeffrey D. Silberman,²1 Alastair G. B. Simpson,³2, Shigeharu Moriya,§ Toshiaki Kudo,§ Moriya Ohkuma,§ and Rosemary J. Red®eld\ *Program in Evolutionary Biology, Canadian Institute for Advanced Research, Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada; ²Josephine Bay Paul Center in Comparative Molecular Biology and Evolution, Marine Biological Laboratory, Woods Hole, Massachusetts; ³School of Biological Sciences, University of Sydney, New South Wales, Australia; §Institute of Physical and Chemical Research and Japan Science and Technology Corporation, Wako, Saitama, Japan; and \Department of Zoology, University of British Columbia, Vancouver, British Columbia, Canada Despite intensive study in recent years, large-scale eukaryote phylogeny remains poorly resolved. This is particularly problematic among the groups considered to be potential early branches. In many recent systematic schemes for early eukaryotic evolution, the amitochondriate protists oxymonads and Trimastix have ®gured prominently, having been suggested as members of many of the putative deep-branching higher taxa. However, they have never before been proposed as close relatives of each other. We ampli®ed, cloned, and sequenced small-subunit ribosomal RNA genes from the oxymonad Pyrsonympha and from several Trimastix isolates. Rigorous phylogenetic analyses indicate that these two protist groups are sister taxa and are not clearly related to any currently established eukaryotic lineages. This surprising result has important implications for our understanding of cellular evolution and high-level eukaryotic phylogeny. Given that Trimastix contains small, electron-dense bodies strongly suspected to be derived mitochondria, this study constitutes the best evidence to date that oxymonads are not primitively amitochondriate. Instead, Trimastix and oxymonads may be useful organisms for investigations into the evolution of the secondary amitochondriate condition. All higher taxa involving either oxymonads or Trimastix may require modi®cation or abandonment. Affected groups include four contemporary taxa given the rank of phylum (Metamonada, Loukozoa, Trichozoa, Percolozoa), and the informal excavate taxa. A new ``phylum-level'' taxon may be warranted for oxy- monads and Trimastix. Introduction Recent years have seen increasing uncertainty Cleveland 1956). Some oxymonads, such as Saccino- about the broadest-scale structure of the eukaryotic evo- baculus and Oxymonas, undergo self-fusion of gametes lutionary tree, particularly the identity of the deepest (autogamy). These taxa are thought to have a one-step extant branches. These dif®culties have been revealed meiosis, in which a single reductive division produces by the implementation of novel analysis methods (Stiller two daughter cells, instead of the two divisions and four and Hall 1999), the use of different models of evolution daughter cells typical of meiosis in other organisms (but (Silberman et al. 1999), and the use of genes giving see Haig 1993). Other oxymonads, such as Pyrsonym- con¯icting results (Embley and Hirt 1998). Another ma- pha, do not undergo true sexual reproduction, but, rather, jor problem is the absence of many key protist groups have a ploidy cycle in which their initially high ploidy from most or all molecular phylogenies. Oxymonads is reduced by a series of apparently meiotic divisions and Trimastix are two such key groups. and then restored by multiple rounds of DNA replication Oxymonads are a group of structurally distinct, ob- (Hollande and Carruette-Valentin 1970). Unlike most ligately symbiotic ¯agellates (usually with four ¯agella eukaryotes, oxymonads also lack mitochondria and Gol- per cell), most of which are cellulose digesters found in gi dictyosomes (Brugerolle 1991). This cytological sim- the hindgut of termites and wood-eating cockroaches. plicity, especially the lack of mitochondria, led to oxy- First described by Leidy in 1877, oxymonads are best monads being advanced as one of the most primitive known for their atypical sexual cycles, described in a groups of eukaryotes (Cavalier-Smith 1981). long series of papers by Cleveland (summarized by The relationships of oxymonads with other eukary- otes are uncertain and contentious. In the modern era, 1 Present address: UCLA Institute of Geophysics and Planetary they have generally been allied with the other cytolog- Physics and Department of Microbiology and Immunology, University ically simple, amitochondriate, tetra¯agellate protists, of California±Los Angeles. i.e., the retortamonads and diplomonads. These groups 2 Present address: Department of Biochemistry and Molecular Bi- formed the widely accepted phylum Metamonada, unit- ology, Dalhousie University, Halifax, Nova Scotia, Canada. ed by their shared possession of four anterior basal bod- Abbreviations: ML, maximum likelihood; sp., species; ssu rDNA, ies and lack of organelles (Cavalier-Smith 1981, 1998). small-subunit ribosomal RNA gene. However, the distinctive presence of a motile axostyle, Key words: ssu rDNA, eukaryote evolution, protist, phylogenet- a cytoskeletal backbone running the length of oxymonad ics, metamonad, mitochondria, sex. cells, sets the oxymonads apart from the other meta- Address for correspondence and reprints: Joel B. Dacks, Program monads. In his 1991 review, Brugerolle suggested that in Evolutionary Biology, Canadian Institute for Advanced Research, there was ``a probable long evolutionary distance be- Department of Biochemistry and Molecular Biology, Dalhousie Uni- tween this group and the other two.'' Recent elongation versity, Halifax, Nova Scotia, Canada B3H 4H7. E-mail: [email protected]. factor (EF-1 alpha) phylogenies that include the ®rst Mol. Biol. Evol. 18(6):1034±1044. 2001 gene sequence data from oxymonads (Moriya, Ohkuma, q 2001 by the Society for Molecular Biology and Evolution. ISSN: 0737-4038 and Kudo 1998; Dacks and Roger 1999) indicate that a 1034 An Oxymonad-Trimastix Clade 1035 close relationship with diplomonads is unlikely. Newer four rDNA sequences to each other and to other eu- accounts of eukaryotic diversity instead place oxymon- karyotic taxa was determined by phylogenetic analysis. ads with Heterolobosea and Stephanopogon in the con- tentious phylum Percolozoa (Cavalier-Smith 1999, Materials and Methods 2000) or simply describe them as ``eukaryotic taxa with- Protist Isolation and Gene Ampli®cation out known sister groups'' (Patterson 1999). The genus Trimastix was ®rst described by Kent in Pyrsonympha cells were obtained from specimens 1880 but has only recently become the subject of de- of the Western subterranean termite (Reticulitermes hes- tailed study by evolutionary protistologists. Trimastix perus), a species known to harbor the oxymonads Pyr- are free-living anaerobes/microaerophiles with four ¯a- sonympha and Dinenympha (Grosovsky and Margulis gella and a broad ventral feeding groove. Ultrastructural 1982), collected from a natural colony near Kelowna, examinations have revealed that Trimastix lack classical Canada. Termite gut contents were diluted into modi®ed mitochondria, having instead small, membrane-bounded Trager's media (Buhse, Stamler, and Smith 1975). The organelles resembling hydrogenosomes (O'Kelly 1993; largest cells with typical Pyrsonympha morphology Brugerolle and Patterson 1997; Simpson, Bernard, and were selected away from nonoxymonad ¯agellates by Patterson 2000). The discovery of these organelles micromanipulation, washed, and reselected. Due to the prompted Cavalier-Smith (1997) to group Trimastix with dif®culty of manipulation and identi®cation, the cells the hydrogenosome-bearing parabasalids in a new phy- were identi®able only as Pyrsonympha sp. lum, Trichozoa. However, detailed ultrastructural ex- About 50±75 cells were pelleted by centrifugation aminations also demonstrated that Trimastix shares a at 3,000 rpm for 1 min, and DNA was extracted using large number of cytoskeletal similarities with a seem- standard techniques (Maniatis, Fritsch, and Sambrook ingly diverse collection of mitochondriate and amito- 1982). The 39 region of the Pyrsonympha sp. ssu rDNA chondriate protists that also have feeding grooves: the gene (639 nt) was ampli®ed by PCR, using eukaryotic retortamonads, core jakobids (Reclinomonas, Jakoba, speci®c primer 59N (TGAAACTTAAAGGAATTGA- and Histiona), Malawimonas, Carpediemonas, some di- CGGA) and primer B from Medlin et al. (1988). Cycling plomonads, and some Heterolobosea (O'Kelly, Farmer, parameters began with an initial denaturation of 958C and Nerad 1999; O'Kelly and Nerad 1999; Patterson for 1 min, followed by 1 min at 458C and 3 min at 728C. 1999; Simpson and Patterson 1999). Trimastix has been This cycle was repeated an additional 29 times with the included with these groups in the informal assemblage initial heating step at 948C for 10 s, and was followed ``excavate taxa,'' envisaged as a monophyletic or para- by a ®nal cycle with extension time increased to 4 min phyletic group (Simpson and Patterson 1999). Cavalier- to promote the complete extension of products. The re- Smith (1999) recently rejected Trichozoa and instead sulting PCR products were cloned into a pGem-T vector erected a new phylum, Loukozoa, based on the shared (Promega BioTech, Madison, Wis.) and sequenced on presence of a ventral feeding groove (and referring to an ABI sequencer. the presence of either mitochondria or mitochondrion Once the identity of
Load more

Recommended publications
  • Morphology, Phylogeny, and Diversity of Trichonympha (Parabasalia: Hypermastigida) of the Wood-Feeding Cockroach Cryptocercus Punctulatus
    J. Eukaryot. Microbiol., 56(4), 2009 pp. 305–313 r 2009 The Author(s) Journal compilation r 2009 by the International Society of Protistologists DOI: 10.1111/j.1550-7408.2009.00406.x Morphology, Phylogeny, and Diversity of Trichonympha (Parabasalia: Hypermastigida) of the Wood-Feeding Cockroach Cryptocercus punctulatus KEVIN J. CARPENTER, LAWRENCE CHOW and PATRICK J. KEELING Canadian Institute for Advanced Research, Botany Department, University of British Columbia, University Boulevard, Vancouver, BC, Canada V6T 1Z4 ABSTRACT. Trichonympha is one of the most complex and visually striking of the hypermastigote parabasalids—a group of anaerobic flagellates found exclusively in hindguts of lower termites and the wood-feeding cockroach Cryptocercus—but it is one of only two genera common to both groups of insects. We investigated Trichonympha of Cryptocercus using light and electron microscopy (scanning and transmission), as well as molecular phylogeny, to gain a better understanding of its morphology, diversity, and evolution. Microscopy reveals numerous new features, such as previously undetected bacterial surface symbionts, adhesion of post-rostral flagella, and a dis- tinctive frilled operculum. We also sequenced small subunit rRNA gene from manually isolated species, and carried out an environmental polymerase chain reaction (PCR) survey of Trichonympha diversity, all of which strongly supports monophyly of Trichonympha from Cryptocercus to the exclusion of those sampled from termites. Bayesian and distance methods support a relationship between Tricho- nympha species from termites and Cryptocercus, although likelihood analysis allies the latter with Eucomonymphidae. A monophyletic Trichonympha is of great interest because recent evidence supports a sister relationship between Cryptocercus and termites, suggesting Trichonympha predates the Cryptocercus-termite divergence.
    [Show full text]
  • Download This Publication (PDF File)
    PUBLIC LIBRARY of SCIENCE | plosgenetics.org | ISSN 1553-7390 | Volume 2 | Issue 12 | DECEMBER 2006 GENETICS PUBLIC LIBRARY of SCIENCE www.plosgenetics.org Volume 2 | Issue 12 | DECEMBER 2006 Interview Review Knight in Common Armor: 1949 Unraveling the Genetics 1956 An Interview with Sir John Sulston e225 of Human Obesity e188 Jane Gitschier David M. Mutch, Karine Clément Research Articles Natural Variants of AtHKT1 1964 The Complete Genome 2039 Enhance Na+ Accumulation e210 Sequence and Comparative e206 in Two Wild Populations of Genome Analysis of the High Arabidopsis Pathogenicity Yersinia Ana Rus, Ivan Baxter, enterocolitica Strain 8081 Balasubramaniam Muthukumar, Nicholas R. Thomson, Sarah Jeff Gustin, Brett Lahner, Elena Howard, Brendan W. Wren, Yakubova, David E. Salt Matthew T. G. Holden, Lisa Crossman, Gregory L. Challis, About the Cover Drosophila SPF45: A Bifunctional 1974 Carol Churcher, Karen The jigsaw image of representatives Protein with Roles in Both e178 Mungall, Karen Brooks, Tracey of various lines of eukaryote evolution Splicing and DNA Repair Chillingworth, Theresa Feltwell, refl ects the current lack of consensus as Ahmad Sami Chaouki, Helen K. Zahra Abdellah, Heidi Hauser, to how the major branches of eukaryotes Salz Kay Jagels, Mark Maddison, fi t together. The illustrations from upper Sharon Moule, Mandy Sanders, left to bottom right are as follows: a single Mammalian Small Nucleolar 1984 Sally Whitehead, Michael A. scale from the surface of Umbellosphaera; RNAs Are Mobile Genetic e205 Quail, Gordon Dougan, Julian Amoeba, the large amoeboid organism Elements Parkhill, Michael B. Prentice used as an introduction to protists for Michel J. Weber many school children; Euglena, the iconic Low Levels of Genetic 2052 fl agellate that is often used to challenge Soft Sweeps III: The Signature 1998 Divergence across e215 ideas of plants (Euglena has chloroplasts) of Positive Selection from e186 Geographically and and animals (Euglena moves); Stentor, Recurrent Mutation Linguistically Diverse one of the larger ciliates; Cacatua, the Pleuni S.
    [Show full text]
  • New Zealand's Genetic Diversity
    1.13 NEW ZEALAND’S GENETIC DIVERSITY NEW ZEALAND’S GENETIC DIVERSITY Dennis P. Gordon National Institute of Water and Atmospheric Research, Private Bag 14901, Kilbirnie, Wellington 6022, New Zealand ABSTRACT: The known genetic diversity represented by the New Zealand biota is reviewed and summarised, largely based on a recently published New Zealand inventory of biodiversity. All kingdoms and eukaryote phyla are covered, updated to refl ect the latest phylogenetic view of Eukaryota. The total known biota comprises a nominal 57 406 species (c. 48 640 described). Subtraction of the 4889 naturalised-alien species gives a biota of 52 517 native species. A minimum (the status of a number of the unnamed species is uncertain) of 27 380 (52%) of these species are endemic (cf. 26% for Fungi, 38% for all marine species, 46% for marine Animalia, 68% for all Animalia, 78% for vascular plants and 91% for terrestrial Animalia). In passing, examples are given both of the roles of the major taxa in providing ecosystem services and of the use of genetic resources in the New Zealand economy. Key words: Animalia, Chromista, freshwater, Fungi, genetic diversity, marine, New Zealand, Prokaryota, Protozoa, terrestrial. INTRODUCTION Article 10b of the CBD calls for signatories to ‘Adopt The original brief for this chapter was to review New Zealand’s measures relating to the use of biological resources [i.e. genetic genetic resources. The OECD defi nition of genetic resources resources] to avoid or minimize adverse impacts on biological is ‘genetic material of plants, animals or micro-organisms of diversity [e.g. genetic diversity]’ (my parentheses).
    [Show full text]
  • Broadly Sampled Multigene Analyses Yield a Well-Resolved Eukaryotic Tree of Life
    Smith ScholarWorks Biological Sciences: Faculty Publications Biological Sciences 10-1-2010 Broadly Sampled Multigene Analyses Yield a Well-Resolved Eukaryotic Tree of Life Laura Wegener Parfrey University of Massachusetts Amherst Jessica Grant Smith College Yonas I. Tekle Smith College Erica Lasek-Nesselquist Marine Biological Laboratory Hilary G. Morrison Marine Biological Laboratory See next page for additional authors Follow this and additional works at: https://scholarworks.smith.edu/bio_facpubs Part of the Biology Commons Recommended Citation Parfrey, Laura Wegener; Grant, Jessica; Tekle, Yonas I.; Lasek-Nesselquist, Erica; Morrison, Hilary G.; Sogin, Mitchell L.; Patterson, David J.; and Katz, Laura A., "Broadly Sampled Multigene Analyses Yield a Well-Resolved Eukaryotic Tree of Life" (2010). Biological Sciences: Faculty Publications, Smith College, Northampton, MA. https://scholarworks.smith.edu/bio_facpubs/126 This Article has been accepted for inclusion in Biological Sciences: Faculty Publications by an authorized administrator of Smith ScholarWorks. For more information, please contact [email protected] Authors Laura Wegener Parfrey, Jessica Grant, Yonas I. Tekle, Erica Lasek-Nesselquist, Hilary G. Morrison, Mitchell L. Sogin, David J. Patterson, and Laura A. Katz This article is available at Smith ScholarWorks: https://scholarworks.smith.edu/bio_facpubs/126 Syst. Biol. 59(5):518–533, 2010 c The Author(s) 2010. Published by Oxford University Press, on behalf of the Society of Systematic Biologists. All rights reserved. For Permissions, please email: [email protected] DOI:10.1093/sysbio/syq037 Advance Access publication on July 23, 2010 Broadly Sampled Multigene Analyses Yield a Well-Resolved Eukaryotic Tree of Life LAURA WEGENER PARFREY1,JESSICA GRANT2,YONAS I. TEKLE2,6,ERICA LASEK-NESSELQUIST3,4, 3 3 5 1,2, HILARY G.
    [Show full text]
  • The Oxymonad Genome Displays Canonical Eukaryotic Complexity in the Absence of a Mitochondrion Anna Karnkowska,*,1,2 Sebastian C
    The Oxymonad Genome Displays Canonical Eukaryotic Complexity in the Absence of a Mitochondrion Anna Karnkowska,*,1,2 Sebastian C. Treitli,1 Ondrej Brzon, 1 Lukas Novak,1 Vojtech Vacek,1 Petr Soukal,1 Lael D. Barlow,3 Emily K. Herman,3 Shweta V. Pipaliya,3 TomasPanek,4 David Zihala, 4 Romana Petrzelkova,4 Anzhelika Butenko,4 Laura Eme,5,6 Courtney W. Stairs,5,6 Andrew J. Roger,5 Marek Elias,4,7 Joel B. Dacks,3 and Vladimır Hampl*,1 1Department of Parasitology, BIOCEV, Faculty of Science, Charles University, Vestec, Czech Republic 2Department of Molecular Phylogenetics and Evolution, Faculty of Biology, Biological and Chemical Research Centre, University of Warsaw, Warsaw, Poland 3Division of Infectious Disease, Department of Medicine, University of Alberta, Edmonton, Canada 4Department of Biology and Ecology, Faculty of Science, University of Ostrava, Ostrava, Czech Republic Downloaded from https://academic.oup.com/mbe/article-abstract/36/10/2292/5525708 by guest on 13 January 2020 5Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Canada 6Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden 7Institute of Environmental Technologies, Faculty of Science, University of Ostrava, Ostrava, Czech Republic *Corresponding authors: E-mails: [email protected]; [email protected]. Associate editor: Fabia Ursula Battistuzzi Abstract The discovery that the protist Monocercomonoides exilis completely lacks mitochondria demonstrates that these organ- elles are not absolutely essential to eukaryotic cells. However, the degree to which the metabolism and cellular systems of this organism have adapted to the loss of mitochondria is unknown. Here, we report an extensive analysis of the M.
    [Show full text]
  • Multigene Eukaryote Phylogeny Reveals the Likely Protozoan Ancestors of Opis- Thokonts (Animals, Fungi, Choanozoans) and Amoebozoa
    Accepted Manuscript Multigene eukaryote phylogeny reveals the likely protozoan ancestors of opis- thokonts (animals, fungi, choanozoans) and Amoebozoa Thomas Cavalier-Smith, Ema E. Chao, Elizabeth A. Snell, Cédric Berney, Anna Maria Fiore-Donno, Rhodri Lewis PII: S1055-7903(14)00279-6 DOI: http://dx.doi.org/10.1016/j.ympev.2014.08.012 Reference: YMPEV 4996 To appear in: Molecular Phylogenetics and Evolution Received Date: 24 January 2014 Revised Date: 2 August 2014 Accepted Date: 11 August 2014 Please cite this article as: Cavalier-Smith, T., Chao, E.E., Snell, E.A., Berney, C., Fiore-Donno, A.M., Lewis, R., Multigene eukaryote phylogeny reveals the likely protozoan ancestors of opisthokonts (animals, fungi, choanozoans) and Amoebozoa, Molecular Phylogenetics and Evolution (2014), doi: http://dx.doi.org/10.1016/ j.ympev.2014.08.012 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. 1 1 Multigene eukaryote phylogeny reveals the likely protozoan ancestors of opisthokonts 2 (animals, fungi, choanozoans) and Amoebozoa 3 4 Thomas Cavalier-Smith1, Ema E. Chao1, Elizabeth A. Snell1, Cédric Berney1,2, Anna Maria 5 Fiore-Donno1,3, and Rhodri Lewis1 6 7 1Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, UK.
    [Show full text]
  • Primary Amoebic Meningoencephalitis Due to Naegleria Fowleri
    56 Case report Primary amoebic meningoencephalitis due to Naegleria fowleri A. Angrup, L. Chandel, A. Sood, K. Thakur, S. C. Jaryal Department of Microbiology,Dr. Rajendra Prasad Government Medical College, Kangra at Tanda, Himachal Pradesh, Pin Code- 176001, India. Correspondence to: Dr. Archana Angrup, Department of Microbiology, Dr. Rajendra Prasad Government Medical College, Kangra, Tanda, Himachal Pradesh, Pin Code-176001, India. Phone no. 09418119222, Facsimile: 01892-267115 Email: [email protected] Abstract The genus Naegleria comprises of free living ameboflagellates found in soil and fresh water. More than 30 species have been isolated but only N. fowleri has been associated with human disease. N. fowleri causes primary amoebic meningoencephalitis (PAM), an acute, often fulminant infection of CNS. Here we report a rare and first case of PAM in an immunocompetent elderly patient from this part of the country. Amoeboid and flagellate forms of N. fowleri were detected in the direct microscopic examination of CSF and confirmed by flagellation test in distilled water, demonstrating plaques /clear areas on 1.5% non nutrient agar and its survival at 42°C. Keywords: Meningitis, Naegleria fowleri, primary amoebic meningoencephalitis Introduction of our knowledge, in India, only eight cases have been reported so far .1, 5-8 Infection of the central nervous system (CNS) in human We hereby report a rare case of PAM in elderly beings with free living amoebae is uncommon. Among the immunocompetent patient from the hilly state of Himachal many different genera of amoebae, Naegleria spp, Pradesh (H.P) in Northern India. Acanthamoeba spp and Balamuthia spp are primarily pathogenic to the CNS.
    [Show full text]
  • Biosystems, 10 (1978) 67--89 67 © Elsevier/North-Holland Scientific Publishers Ltd. PROBLEMS in the DEVELOPMENT of an EXPLICIT
    BioSystems, 10 (1978) 67--89 67 © Elsevier/North-Holland Scientific Publishers Ltd. PROBLEMS IN THE DEVELOPMENT OF AN EXPLICIT HYPOTHETICAL PHYLOGENY OF THE LOWER EUKARYOTES F.J.R. TAYLOR Department of Botany and Institute of Oceanography, The University of British Columbia, Vancouver, B.C., Canada V6T 1 W5 A semi-explicit arrangement of the lower eukaryotes is provided to serve as a basis for phyletic discussions. No single character is used to determine the position of all the groups. The tree provides no ready separation of protozoa, algae and fungi, groups assigned to these traditional assemblages being considered to be for the most part inextricably interwoven. Photosynthetic forms, whose relationships seem to be more readily discernable, are considered to have given rise repeatedly to nonphotosynthetic forms. The assumption that there are primitive "preflagellar" eukaryotes (red algae, non-flagellated fungi) is adopted. The potential value of mitochondrial features as indicators of broad affinities is emphasised, particularly in determining the probable affinities of non-photosynthetic forms, and this criterion is contra-indicative of a ciliate ancestry for the Metazoa. In the arrangement provided the distributions of chloroplast, mitochondrial and flagellar features match one another well, suggesting their probable co-evolution. 1. Introduction view of the relations of the algae, his "tree" contained numerous, not strictly representa- At the start of a paper of this type it is tional "twigs". Dodge {1974) was even less often appropriate to begin with an apt, but explicit, preferring to comment more on not very serious quotation to set the right taxonomic consequences. Leedale (1974) tone. In this instmace, the only quotation preferred to ignore the details of origin of which sprang readily to mind was "..
    [Show full text]
  • Emerging Genomic and Proteomic Evidence on Relationships Among the Animal, Plant and Fungal Kingdoms
    Review Emerging Genomic and Proteomic Evidence on Relationships Among the Animal, Plant and Fungal Kingdoms John W. Stiller Department of Biology, East Carolina University, Greenville, NC 27858, USA. Sequence-based molecular phylogenies have provided new models of early eu- karyotic evolution. This includes the widely accepted hypothesis that animals are related most closely to fungi, and that the two should be grouped together as the Opisthokonta. Although most published phylogenies have supported an opisthokont relationship, a number of genes contain a tree-building signal that clusters animal and green plant sequences, to the exclusion of fungi. The alter- native tree-building signal is especially intriguing in light of emerging data from genomic and proteomic studies that indicate striking and potentially synapomor- phic similarities between plants and animals. This paper reviews these new lines of evidence, which have yet to be incorporated into models of broad scale eukaryotic evolution. Key words: genomics, proteomics, evolution, animals, plants, fungi Introduction The results of sequence-based, molecular phylogenetic two di®erent and conflicting phylogenetic signals; analyses have reshaped current thinking about an- most available sequences supported an animals + cient evolutionary relationships, and have begun to es- fungi relationship, but a smaller subset of genes in- tablish a new framework for systematizing broad-scale dicated a closer relationship between animals and eukaryotic diversity. Among the most widely accepted plants. Curiously, there was little or no support of the new evolutionary hypotheses is a proposed for the third possible relationship (plants + fungi). sister relationship between animals (+ choanoflagel- This suggested that a persistent phylogenetic artifact, lates) and fungi (see ref.
    [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]
  • University of Copenhagen
    Combined morphological and phylogenomic re-examination of malawimonads, a critical taxon for inferring the evolutionary history of eukaryotes Heiss, Aaron A.; Kolisko, Martin; Ekelund, Fleming; Brown, Matthew W.; Roger, Andrew J.; Simpson, Alastair G. B. Published in: Royal Society Open Science DOI: 10.1098/rsos.171707 Publication date: 2018 Document version Publisher's PDF, also known as Version of record Citation for published version (APA): Heiss, A. A., Kolisko, M., Ekelund, F., Brown, M. W., Roger, A. J., & Simpson, A. G. B. (2018). Combined morphological and phylogenomic re-examination of malawimonads, a critical taxon for inferring the evolutionary history of eukaryotes. Royal Society Open Science, 5(4), 1-13. [171707]. https://doi.org/10.1098/rsos.171707 Download date: 09. Apr. 2020 Downloaded from http://rsos.royalsocietypublishing.org/ on September 28, 2018 Combined morphological and phylogenomic rsos.royalsocietypublishing.org re-examination of Research malawimonads, a critical Cite this article: Heiss AA, Kolisko M, Ekelund taxon for inferring the F,BrownMW,RogerAJ,SimpsonAGB.2018 Combined morphological and phylogenomic re-examination of malawimonads, a critical evolutionary history taxon for inferring the evolutionary history of eukaryotes. R. Soc. open sci. 5: 171707. of eukaryotes http://dx.doi.org/10.1098/rsos.171707 Aaron A. Heiss1,2,†, Martin Kolisko3,4,†, Fleming Ekelund5, Matthew W. Brown6,AndrewJ.Roger3 and Received: 23 October 2017 2 Accepted: 6 March 2018 Alastair G. B. Simpson 1Department of Invertebrate Zoology
    [Show full text]
  • Novel Lineages of Oxymonad Flagellates from the Termite Porotermes Adamsoni (Stolotermitidae): the Genera Oxynympha and Termitim
    Protist, Vol. 170, 125683, December 2019 http://www.elsevier.de/protis Published online date 21 October 2019 ORIGINAL PAPER Novel Lineages of Oxymonad Flagellates from the Termite Porotermes adamsoni (Stolotermitidae): the Genera Oxynympha and Termitimonas a,1 b a c b,1 Renate Radek , Katja Meuser , Samet Altinay , Nathan Lo , and Andreas Brune a Evolutionary Biology, Institute for Biology/Zoology, Freie Universität Berlin, 14195 Berlin, Germany b Research Group Insect Gut Microbiology and Symbiosis, Max Planck Institute for Terrestrial Microbiology, 35043 Marburg, Germany c School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW 2006, Australia Submitted January 21, 2019; Accepted October 9, 2019 Monitoring Editor: Alastair Simpson The symbiotic gut flagellates of lower termites form host-specific consortia composed of Parabasalia and Oxymonadida. The analysis of their coevolution with termites is hampered by a lack of informa- tion, particularly on the flagellates colonizing the basal host lineages. To date, there are no reports on the presence of oxymonads in termites of the family Stolotermitidae. We discovered three novel, deep-branching lineages of oxymonads in a member of this family, the damp-wood termite Porotermes adamsoni. One tiny species (6–10 ␮m), Termitimonas travisi, morphologically resembles members of the genus Monocercomonoides, but its SSU rRNA genes are highly dissimilar to recently published sequences of Polymastigidae from cockroaches and vertebrates. A second small species (9–13 ␮m), Oxynympha loricata, has a slight phylogenetic affinity to members of the Saccinobaculidae, which are found exclusively in wood-feeding cockroaches of the genus Cryptocercus, the closest relatives of termites, but shows a combination of morphological features that is unprecedented in any oxymonad family.
    [Show full text]