DOCSLIB.ORG

Evidence That an Amoeba Acquired a Chloroplast by Retaining Part of An

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Evidence That an Amoeba Acquired a Chloroplast by Retaining Part of An Proc. Nati. Acad. Sci. USA Vol. 91, pp. 3690-3694, April 1994 Evolution Evidence that an amoeba acquired a chloroplast by retaining part of an engulfed eukaryotic alga (chioroat or /endsymblss/in situ hybrldlzaton/rRNA phylogeny) GEOFFREY I. MCFADDEN*t, PAUL R. GILSON*, CLAUDIA J. B. HOFMANNt, GREGORY J. ADCOCK*, AND UWE-G. MAIERt *Plant Cell Biology Research Centre, School of Botany, University of Melbourne, Parkville, Victoria 3052, Australia; and *Institut fMr Biologie II, Zellbiologie, Universitit Freiburg, SchAzlestrasse 1, W-7914 Freiburg, Germany Communicated by Adrienne E. Clarke, November 29, 1993 (receivedfor review July 2, 1993) ABSTRACT Chlorarachniophytes are amoebold algae flagellates, cryptomonads, and chlorarachniophytes-are with unusual chloroplasts. Instead ofthe usual two membranes postulated to have "second-hand" chloroplasts acquired that surround the chloroplasts of plants, green algae, and red from another eukaryote in such a manner (5, 6, 8, 9). algae, the chloroplasts of chlorarachniophytes have four The main line of evidence supporting such secondary boundg membranes. The extra membranes may rect an endosymbioses is the occurrence of extra membranes sur- unusual origin of chlorarachniophyte chloroplasts. Rather rounding the chloroplasts of certain algal groups. Like mito- than inheriting the organelle directly from their anesors, chondria, ordinary chloroplasts are surrounded by two mem- chlorarachniophytes may have adopted the chloroplast of an branes that probably represent the two bacterial membranes, gal cell ingested as prey. Parts of the algal cell are postulated the phagocytotic membrane of the host having been lost (5). to remain within the amoeba as a reduced eukaryotic endo- In certain algae there are not two but four membranes symblont [Hibberd, D. J. & Norris, R. E. (1984)J. Phycol. 20, bounding the chloroplast. The extra pair of membranes are 310-3301. A small nucleus-like structure, proposed to be a proposed to represent the plasma membrane of the eukary- vestige of the endosymblont's nucleus, is located in a space otic endosymbiont and the phagocytotic membrane of the between the second and third chiloroplast membranes. We host cell (see Fig. 1). cloned and sequenced nuclear-type rRNA genes from chlo- If chloroplasts with four membranes were acquired by rarachniophytes and found two highly divergent genes. In situ endosymbiosis of a eukaryote, what has happened to the hybridization shows that one gene is expressed by the amoebal nucleus and cytoplasm of the endosymbiont? In most algae (host) nucleus and the other is expressed by the putative with quadruple chloroplast membranes (e.g., diatoms, brown endosymbiont nucleus, suggestng that the latter is indeed a algae, and golden-brown flagellates), there is no trace ofthese foreign genome. Transcripts from the endosymbiont gene structures, and the hypothesis of secondary endosymbiosis accumulate in the small cytoplasmic compar t between the remains largely untested for these organisms (8). However, in second and third chioroplast membranes, which we believe to two groups, cryptomonads and chlorarachniophytes, struc- be the remnant cytoplasm of the endosymbiont. Using the tures resembling a eukaryotic nucleus and cytoplasm are endosymbiont gene as a probe, we identified three small present within the chloroplast envelopes (8). Recently, it has chromosomes belonging to the endosymbiont nucleus. This been unequivocally demonstrated that the cryptomonads knowledge should allow a detailed molecular analysis of the contain a photosynthetic eukaryotic endosymbiont (9-13), role of the endosymbiont's genome and cytoplasm in the but molecular analysis ofthe chlorarachniophytes is wanting. partnership. Chlorarachniophytes are reticulopodial amoebae (Phylum Chlorarachnida) with green chloroplasts (14). Between the Photosynthesis first arose in prokaryotes =3500 million years second and third membranes bounding the chloroplast is a ago (1) and was later acquired by eukaryotes through endo- small nucleus-like organelle (15). Known as the nucleomorph symbiosis (2, 3). The chloroplast, the eukaryotic photosyn- because it resembles a nucleus, this structure is bounded by thetic organelle, arose from a photosynthetic prokaryote that a double membrane with pores (15, 16), contains DNA (16), was engulfed and retained by a eukaryotic cell (2, 3). The and may encode cytoplasmic-type rRNAs (17). The compart- emerging similarity between chloroplasts at the molecular ment harboring the nucleomorph, the periplastidal space, level suggests that all chloroplasts probably stem from a contains ribosome-like particles (15-17), and the nucleo- single partnership between a eukaryotic host and a prokary- morph and surrounding periplastidal cytoplasm are suggested otic endosymbiont (4-7). to be the vestigial nucleus and cytoplasm of a chloroplast- While all chloroplasts may thus have a single origin, it does containing eukaryotic endosymbiont (15-17). not necessarily follow that all organisms with chloroplasts Ifchlorarachniophytes truly harbor a eukaryotic endosym- represent a single (monophyletic) evolutionary lineage. Lat- biont, then they are essentially one eukaryotic cell inside eral transfer ofchloroplasts between eukaryotic lineages, via another. The nucleomorph would be a foreign genome, and a secondary endosymbiosis, has been postulated to explain nucleomorph genes would be expected to have different the anomalous occurrence of chloroplasts in otherwise dis- sequences to homologous genes from the host nucleus. tantly related groups of protists (5, 6, 8, 9). Such lateral Moreover, the nucleomorph DNA should encode compo- transfers are believed to have occurred when phagotrophic nents, such as rRNAs, for maintenance of its surrounding protozoans engulfed algal cells and retained them as endo- cytoplasm in the periplastidal space. Because they are orig- symbionts. Several groups of algae-including dinoflagel- inally derived from a foreign cell, rRNAs in the periplastidal lates, euglenoids, brown algae, diatoms, golden/brown cytoplasm would be expected to have a different nucleotide sequence to rRNAs in the main cytoplasmic compartment of The publication costs ofthis article were defrayed in part by page charge payment. This article must therefore be hereby marked "advertisement" Abbreviation: srRNA, small subunit rRNA. in accordance with 18 U.S.C. §1734 solely to indicate this fact. tTo whom reprint requests should be addressed. 3690 Downloaded by guest on September 26, 2021 Evolution: McFadden et al. Proc. Natl. Acad. Sci. USA 91 (1994) 3691 I# -cj\ . Ici ..k\X\ . Ici ' *",' It., eFP' ,P - 6.1 Vi &lb I'd e eN,(t, '.0 'o a09 , _p 6 ,O sA& e\I,.So f q;vv 3.0kb 2.0kb 0 1.6kb l.Okb primary secondary endosymbiosis endosymbiosis FIG. 1. Hypothetical acquisition of chloroplasts by two sequential endosymbiotic events (15). A eukaryote engulfed a photosynthetic prokaryote (primary endosymbiosis) producing a double-membrane-bound chloroplast (C), as occurs in red algae, green algae, and plants. The algal cell was then engulfed by another eukaryote (secondary endosymbiosis) producing a chloroplast with four membranes. The nucleus (N') and cytoplasm of the engulfed algal cell are located between the second and third chloroplast membranes. PCR amplification of rRNA genes from chlorarachniophytes using universal eukaryotic primers gave two products. We show by in situ hybridization (Fig. 2) that one gene is from the host nucleus and the other gene is from a reduced endosymbiont nucleus. the host cell, which would be encoded by the host nucleus 42 in variable domain 7 (22) was used as a probe specific for (Fig. 1). the longer gene. For the shorter gene, a 115-bp fragment We cloned cytoplasmic-type small subunit rRNA (srRNA) (positions 615-729) from helices E21.1 through E21.2 in genes from chlorarachniophytes and identified two highly variable domain 4 (22) was used. divergent srRNA genes.§ We localized transcripts ofthe two In Situ Hybridization. Cells of Chlorarachnion sp. 2 were genes within the cell by in situ hybridization and showed that fixed and embedded for in situ hybridization as described one gene is expressed by the nucleomorph and the other is (23). The gene-specific fragments ofthe long and short genes expressed by the putative host nucleus. To identify chromo- were cloned into a transcription vector and biotinylated sense somes belonging to the endosymbiont genome, we mapped and antisense RNA probes were synthesized. The probes the nucleomorph-specific gene to DNA resolved by pulsed- were hybridized to ultrathin sections and bound probe was field gel electrophoresis. detected with anti-biotin immunogold markers as described (23). Northern Blot Analysis. Total RNA was isolated from MATERIALS AND METHODS Chlorarachnion sp. 2 as described (24), electrophoresed in a Cells and PCR Amplification. Four chlorarachniophyte denaturing agarose gel (1.5%) and then transferred to strains [Chlorarachnion reptans (CCMP 238), Chlorarach- ZetaProbe nylon membrane (Bio-Rad) as recommended by nion reptans (ref. 18), Chlorarachnion sp. 1 (CCMP 1408), the manufacturer. The blot was stripped between probings and Chlorarachnion sp. 2 (CCMP 242)] were cultured as and removal ofthe probe was monitored by autoradiography described (15), and total DNA was isolated as described (19). prior to reprobing. Autoradiograms were exposed for 1 h at Nuclei were isolated as described (12). Universal cytoplas- room temperature (see Fig. 3, lanes C and D), 20 h at -700C mic-type srRNA gene primers
Load more

Recommended publications
  • Molecular Data and the Evolutionary History of Dinoflagellates by Juan Fernando Saldarriaga Echavarria Diplom, Ruprecht-Karls-Un
    Molecular data and the evolutionary history of dinoflagellates by Juan Fernando Saldarriaga Echavarria Diplom, Ruprecht-Karls-Universitat Heidelberg, 1993 A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY in THE FACULTY OF GRADUATE STUDIES Department of Botany We accept this thesis as conforming to the required standard THE UNIVERSITY OF BRITISH COLUMBIA November 2003 © Juan Fernando Saldarriaga Echavarria, 2003 ABSTRACT New sequences of ribosomal and protein genes were combined with available morphological and paleontological data to produce a phylogenetic framework for dinoflagellates. The evolutionary history of some of the major morphological features of the group was then investigated in the light of that framework. Phylogenetic trees of dinoflagellates based on the small subunit ribosomal RNA gene (SSU) are generally poorly resolved but include many well- supported clades, and while combined analyses of SSU and LSU (large subunit ribosomal RNA) improve the support for several nodes, they are still generally unsatisfactory. Protein-gene based trees lack the degree of species representation necessary for meaningful in-group phylogenetic analyses, but do provide important insights to the phylogenetic position of dinoflagellates as a whole and on the identity of their close relatives. Molecular data agree with paleontology in suggesting an early evolutionary radiation of the group, but whereas paleontological data include only taxa with fossilizable cysts, the new data examined here establish that this radiation event included all dinokaryotic lineages, including athecate forms. Plastids were lost and replaced many times in dinoflagellates, a situation entirely unique for this group. Histones could well have been lost earlier in the lineage than previously assumed.
    [Show full text]
  • Chlorophyta, Trebouxiophyceae) in Lake Tanganyika (Africa)*
    Biologia 63/6: 799—805, 2008 Section Botany DOI: 10.2478/s11756-008-0101-4 Siderocelis irregularis (Chlorophyta, Trebouxiophyceae) in Lake Tanganyika (Africa)* Maya P. Stoyneva1, Elisabeth Ingolič2,WernerKofler3 &WimVyverman4 1Sofia University ‘St Kliment Ohridski’, Faculty of Biology, Department of Botany, 8 bld. Dragan Zankov, BG-1164 Sofia, Bulgaria; e-mail: [email protected], [email protected]fia.bg 2Graz University of Technology, Research Institute for Electron Microscopy, Steyrergasse 17,A-8010 Graz, Austria; e-mail: [email protected] 3University of Innsbruck, Institute of Botany, Sternwartestrasse 15,A-6020 Innsbruck, Austria; e-mail: werner.kofl[email protected] 4Ghent University, Department Biology, Laboratory of Protistology and Aquatic Ecology, Krijgslaan 281-S8,B-9000 Gent, Belgium; e-mail: [email protected] Abstract: Siderocelis irregularis Hindák, representing a genus Siderocelis (Naumann) Fott that is known from European temperate waters, was identified as a common phytoplankter in Lake Tanganyika. It was found aposymbiotic as well as ingested (possibly endosymbiotic) in lake heterotrophs, mainly Strombidium sp. and Vorticella spp. The morphology and ultrastructure of the species, studied with LM, SEM and TEM, are described with emphasis on the structure of the cell wall and the pyrenoid. Key words: Chlorophyta; cell wall; pyrenoid; symbiosis; ciliates; Strombidium; Vorticella Introduction ics of symbiotic species in general came into alignment with that of free-living algae and the term ‘zoochlorel- Tight partnerships between algae and aquatic inver- lae’ was abandoned as being taxonomically ambiguous tebrates, including symbiotic relationships, have long (e.g. Bal 1968; Reisser & Wiessner 1984; Taylor 1984; been of interest and a number of excellent reviews are Reisser 1992a).
    [Show full text]
  • Toxicity, Physiological, and Ultrastructural Effects of Arsenic
    International Journal of Environmental Research and Public Health Article Toxicity, Physiological, and Ultrastructural Effects of Arsenic and Cadmium on the Extremophilic Microalga Chlamydomonas acidophila Silvia Díaz 1, Patricia De Francisco 1,2, Sanna Olsson 3 , Ángeles Aguilera 2,*, Elena González-Toril 2 and Ana Martín-González 1 1 Department of Genetics, Physiology and Microbiology, Faculty of Biology, Universidad Complutense de Madrid (UCM), C/José Antonio Novais, 12, 28040 Madrid, Spain; [email protected] (S.D.); [email protected] (P.d.F.); [email protected] (A.M.-G.) 2 Astrobiology Center (INTA-CSIC), Carretera de Ajalvir km 4, Torrejón de Ardoz, 28850 Madrid, Spain; [email protected] 3 Department of Forest Ecology and Genetics, INIA Forest Research Center (INIA-CIFOR), Carretera de A Coruña km 7.5, 28040 Madrid, Spain; sanna.olsson@helsinki.fi * Correspondence: [email protected]; Tel.: +34-91-520-6434 Received: 17 December 2019; Accepted: 24 February 2020; Published: 3 March 2020 Abstract: The cytotoxicity of cadmium (Cd), arsenate (As(V)), and arsenite (As(III)) on a strain of Chlamydomonas acidophila, isolated from the Rio Tinto, an acidic environment containing high metal(l)oid concentrations, was analyzed. We used a broad array of methods to produce complementary information: cell viability and reactive oxygen species (ROS) generation measures, ultrastructural observations, transmission electron microscopy energy dispersive x-ray microanalysis (TEM–XEDS), and gene expression. This acidophilic microorganism was affected differently by the tested metal/metalloid: It showed high resistance to arsenic while Cd was the most toxic heavy metal, showing an LC50 = 1.94 µM.
    [Show full text]
  • Closing the Circle in Chlamydomonas the Different Stages of the Calvin-Benson Cycle Take Place in Separate Locations Within the Chloroplast
    INSIGHT CARBON FIXATION Closing the circle In Chlamydomonas the different stages of the Calvin-Benson cycle take place in separate locations within the chloroplast. MARYLOU C MACHINGURA AND JAMES V MORONEY terrestrial plants and both groups have Rubisco Related research article Ku¨ ken A, Sommer enzymes with similar properties. However, land F, Yaneva-Roder L, Mackinder LCM, Ho¨ hne plants rarely have pyrenoids because CO2 dif- M, Geimer S, Jonikas MC, Schroda M, Stitt fuses 10,000 times more rapidly in air than in M, Nikoloski Z, Mettler-Altmann T. 2018. water. Once an aquatic organism has fixed CO2, Effects of microcompartmentation on flux it takes a long time for the next molecule to distribution and metabolic pools in Chlamy- arrive, hence the need for a carbon concentra- domonas reinhardtii chloroplasts. eLife 7: tion mechanism that kicks in when the levels of e37960. DOI: 10.7554/eLife.37960 CO2 get too low. The carbon concentration mechanism in Chla- - mydomonas takes bicarbonate (HCO3 ) from outside the cells and converts it into CO2 that can be used by Rubisco inside the pyrenoid. hen the unicellular green alga Chla- There, Rubisco catalyzes the addition of CO2 mydomonas reinhardtii is viewed onto a molecule known as RuBP to create two W under a microscope, the most promi- molecules of a compound called 3PGA; this is nent object in the cell is a structure called the the first step in the Calvin-Benson cycle, a chain pyrenoid. Located within the chloroplast, the of reactions which results in the creation of organelle where photosynthesis takes place, the organic molecules that the cell needs.
    [Show full text]
  • Effects of Microcompartmentation on Flux Distribution and Metabolic Pools
    RESEARCH ARTICLE Effects of microcompartmentation on flux distribution and metabolic pools in Chlamydomonas reinhardtii chloroplasts Anika Ku¨ ken1,2, Frederik Sommer1†, Liliya Yaneva-Roder1, Luke CM Mackinder3‡, Melanie Ho¨ hne1, Stefan Geimer4, Martin C Jonikas3§, Michael Schroda1†, Mark Stitt1, Zoran Nikoloski1,2, Tabea Mettler-Altmann1,5,6* 1Max Planck Institute of Molecular Plant Physiology, Potsdam-Golm, Germany; 2Bioinformatics Group, Institute of Biochemistry and Biology, University of Potsdam, Potsdam, Germany; 3Department of Plant Biology, Carnegie Institution for Science, Stanford, United States; 4Institute of Cell Biology, University of Bayreuth, Bayreuth, Germany; 5Cluster of Excellence on Plant Sciences, Heinrich-Heine University, Du¨ sseldorf, Germany; 6Institute of Plant Biochemistry, Heinrich-Heine University, Du¨ sseldorf, Germany Abstract Cells and organelles are not homogeneous but include microcompartments that alter *For correspondence: [email protected] the spatiotemporal characteristics of cellular processes. The effects of microcompartmentation on metabolic pathways are however difficult to study experimentally. The pyrenoid is a † Present address: Molecular microcompartment that is essential for a carbon concentrating mechanism (CCM) that improves the Biotechnology and Systems photosynthetic performance of eukaryotic algae. Using Chlamydomonas reinhardtii, we obtained Biology, University of experimental data on photosynthesis, metabolites, and proteins in CCM-induced and CCM- Kaiserslautern, Kaiserslautern,
    [Show full text]
  • The Apicoplast: a Review of the Derived Plastid of Apicomplexan Parasites
    Curr. Issues Mol. Biol. 7: 57-80. Online journalThe Apicoplastat www.cimb.org 57 The Apicoplast: A Review of the Derived Plastid of Apicomplexan Parasites Ross F. Waller1 and Geoffrey I. McFadden2,* way to apicoplast discovery with studies of extra- chromosomal DNAs recovered from isopycnic density 1Botany, University of British Columbia, 3529-6270 gradient fractionation of total Plasmodium DNA. This University Boulevard, Vancouver, BC, V6T 1Z4, Canada group recovered two DNA forms; one a 6kb tandemly 2Plant Cell Biology Research Centre, Botany, University repeated element that was later identifed as the of Melbourne, 3010, Australia mitochondrial genome, and a second, 35kb circle that was supposed to represent the DNA circles previously observed by microscopists (Wilson et al., 1996b; Wilson Abstract and Williamson, 1997). This molecule was also thought The apicoplast is a plastid organelle, homologous to to be mitochondrial DNA, and early sequence data of chloroplasts of plants, that is found in apicomplexan eubacterial-like rRNA genes supported this organellar parasites such as the causative agents of Malaria conclusion. However, as the sequencing effort continued Plasmodium spp. It occurs throughout the Apicomplexa a new conclusion, that was originally embraced with and is an ancient feature of this group acquired by the some awkwardness (“Have malaria parasites three process of endosymbiosis. Like plant chloroplasts, genomes?”, Wilson et al., 1991), began to emerge. apicoplasts are semi-autonomous with their own genome Gradually, evermore convincing character traits of a and expression machinery. In addition, apicoplasts import plastid genome were uncovered, and strong parallels numerous proteins encoded by nuclear genes. These with plastid genomes from non-photosynthetic plants nuclear genes largely derive from the endosymbiont (Epifagus virginiana) and algae (Astasia longa) became through a process of intracellular gene relocation.
    [Show full text]
  • Cryptophyte Farming by Symbiotic Ciliate Host Detected in Situ
    Cryptophyte farming by symbiotic ciliate host detected in situ Dajun Qiua, Liangmin Huanga, and Senjie Linb,1 aChinese Academy of Sciences Key Laboratory of Tropical Marine Bio-Resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China; and bDepartment of Marine Sciences, University of Connecticut, Groton, CT 06340 Edited by David M. Karl, University of Hawaii, Honolulu, HI, and approved September 8, 2016 (received for review July 28, 2016) Protist–alga symbiosis is widespread in the ocean, but its character- as the causative species of the bloom, with no detectable crypto- istics and function in situ remain largely unexplored. Here we report phytes and hardly any other organisms present in the bloom water − the symbiosis of the ciliate Mesodinium rubrum with cryptophyte (Fig. 1B). At 1.03 × 106 cells L 1, M. rubrum abundance in the bloom cells during a red-tide bloom in Long Island Sound. In contrast to was over 100-fold higher than the annual peak in Long Island Sound the current notion that Mesodinium retains cryptophyte chloroplasts (15). Each Mesodinium cell harbored 20 to 30 cryptophyte cells (n = or organelles, our multiapproach analyses reveal that in this bloom 16), which packed the peripheral region of the M. rubrum cells (Fig. the endosymbiotic Teleaulax amphioxeia cells were intact and 1E), with complete cell structures, including cell membranes, nuclei, expressing genes of membrane transporters, nucleus-to-cytoplasm and chloroplasts (Fig. 1C). Taking advantage of the large cell size of RNA transporters, and all major metabolic pathways. Among the Mesodinium spp. (width, 20 to 23 μm; length, 25 to 26 μm), we most highly expressed were ammonium transporters in both organ- picked M.
    [Show full text]
  • Norrisiella Sphaerica Gen
    Norrisiella sphaerica gen. et sp. nov., a new coccoid chlorarachniophyte from Baja California, Mexico 著者 Ota Shuhei, Ueda Kunihiko, Ishida Ken-ichiro journal or Journal of Plant Research publication title volume 120 number 6 page range 661-670 year 2007-11-01 URL http://hdl.handle.net/2297/7674 doi: 10.1007/s10265-007-0115-y Norrisiella sphaerica gen. et sp. nov., a new coccoid chlorarachniophyte from Baja California, Mexico Shuhei Ota1, 2, Kunihiko Ueda1 and Ken-ichiro Ishida2 1Division of Life Sciences, Graduate School of Natural Science and Technology, Kanazawa University, Kakuma, Kanazawa 920-1192, Japan 2Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8572, Japan Running title: Norrisiella sphaerica gen. et sp. nov. Correspondence: Shuhei Ota Laboratory of Plant Systematics and Phylogeny (D508) Institute of Biological Sciences Graduate School of Life and Environmental Sciences University of Tsukuba, 1-1-1, Tennodai, Tsukuba 305-8572, Japan Tel/Fax: +81 (29) 853-7267 Fax: +81 (29) 853-4533 e-mail: [email protected] 1/29 Abstract A new chlorarachniophyte, Norrisiella sphaerica S. Ota et K. Ishida gen. et sp. nov., is described from the coast of Baja California, Mexico. We examined its morphology, ultrastructure and life cycle in detail, using light microscopy, transmission electron microscopy and time-lapse videomicroscopy. We found that this chlorarachniophyte possessed the following characteristics: (i) vegetative cells were coccoid and possessed a cell wall, (ii) a pyrenoid was slightly invaded by plate-like periplastidial compartment from the tip of the pyrenoid, (iii) a nucleomorph was located near the pyrenoid base in the periplastidial compartment, (iv) cells reproduced vegetatively via autospores, and (v) a flagellate stage was present in the life cycle.
    [Show full text]
  • A Taxonomic Reassessment of Chlamydomonas Meslinii (Volvocales, Chlorophyceae) with a Description of Paludistella Gen.Nov
    Phytotaxa 432 (1): 065–080 ISSN 1179-3155 (print edition) https://www.mapress.com/j/pt/ PHYTOTAXA Copyright © 2020 Magnolia Press Article ISSN 1179-3163 (online edition) https://doi.org/10.11646/phytotaxa.432.1.6 A taxonomic reassessment of Chlamydomonas meslinii (Volvocales, Chlorophyceae) with a description of Paludistella gen.nov. HANI SUSANTI1,6, MASAKI YOSHIDA2, TAKESHI NAKAYAMA2, TAKASHI NAKADA3,4 & MAKOTO M. WATANABE5 1Life Science Innovation, School of Integrative and Global Major, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8577, Japan. 2Faculty of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8577, Japan. 3Institute for Advanced Biosciences, Keio University, Tsuruoka, Yamagata, 997-0052, Japan. 4Systems Biology Program, Graduate School of Media and Governance, Keio University, Fujisawa, Kanagawa, 252-8520, Japan. 5Algae Biomass Energy System Development and Research Center, University of Tsukuba. 6Research Center for Biotechnology, Indonesian Institute of Sciences, Jl. Raya Bogor KM 46 Cibinong West Java, Indonesia. Corresponding author: [email protected] Abstract Chlamydomonas (Volvocales, Chlorophyceae) is a large polyphyletic genus that includes numerous species that should be classified into independent genera. The present study aimed to examine the authentic strain of Chlamydomonas meslinii and related strains based on morphological and molecular data. All the strains possessed an asteroid chloroplast with a central pyrenoid and hemispherical papilla; however, they were different based on cell and stigmata shapes. Molecular phylogenetic analyses based on 18S rDNA, atpB, and psaB indicated that the strains represented a distinct subclade in the clade Chloromonadinia. The secondary structure of ITS-2 supported the separation of the strains into four species.
    [Show full text]
  • 23.3 Groups of Protists
    Chapter 23 | Protists 639 cysts that are a protective, resting stage. Depending on habitat of the species, the cysts may be particularly resistant to temperature extremes, desiccation, or low pH. This strategy allows certain protists to “wait out” stressors until their environment becomes more favorable for survival or until they are carried (such as by wind, water, or transport on a larger organism) to a different environment, because cysts exhibit virtually no cellular metabolism. Protist life cycles range from simple to extremely elaborate. Certain parasitic protists have complicated life cycles and must infect different host species at different developmental stages to complete their life cycle. Some protists are unicellular in the haploid form and multicellular in the diploid form, a strategy employed by animals. Other protists have multicellular stages in both haploid and diploid forms, a strategy called alternation of generations, analogous to that used by plants. Habitats Nearly all protists exist in some type of aquatic environment, including freshwater and marine environments, damp soil, and even snow. Several protist species are parasites that infect animals or plants. A few protist species live on dead organisms or their wastes, and contribute to their decay. 23.3 | Groups of Protists By the end of this section, you will be able to do the following: • Describe representative protist organisms from each of the six presently recognized supergroups of eukaryotes • Identify the evolutionary relationships of plants, animals, and fungi within the six presently recognized supergroups of eukaryotes • Identify defining features of protists in each of the six supergroups of eukaryotes. In the span of several decades, the Kingdom Protista has been disassembled because sequence analyses have revealed new genetic (and therefore evolutionary) relationships among these eukaryotes.
    [Show full text]
  • Gymnochlora Dimorpha Sp. Nov., a Chlorarachniophyte with Unique Daughter Cell Behaviour
    Phycologia (2011) Volume 50 (3), 317–326 Published 3 May 2011 Gymnochlora dimorpha sp. nov., a chlorarachniophyte with unique daughter cell behaviour 1,2 3 1 SHUHEI OTA *{,ASTUKO KUDO AND KEN-ICHIRO ISHIDA 1Institute of Biological Sciences, Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1, Tennodai, Tsukuba 305-8572, Japan 2Station Biologique de Roscoff, Universite´ Pierre et Marie Curie (Paris 06), CNRS and UMR 7144, Place Georges Tessier, 29682 Roscoff, France 3The College of Biological Sciences, University of Tsukuba, 1-1-1, Tennodai, Tsukuba 305-8572, Japan OTA S., KUDO A. AND ISHIDA K.-I. 2011. Gymnochlora dimorpha sp. nov., a chlorarachniophyte with unique daughter cell behaviour. Phycologia 50: 317–326. DOI: 10.2216/09-102.1 A new chlorarachniophyte species, Gymnochlora dimorpha sp. nov., was described. This new species was isolated from an enrichment preculture of Padina sp. collected from a subtidal coral reef zone in Republic of Palau. The new strain, P314, was characterized by light and electron microscopy in the present study. Under the culture conditions used here, the amoeboid stage was dominant. Two types of amoeboid cells were found in the cultures: motile and flattened nonmotile (sessile) cells. The motile cells typically multiplied via binary cell division. The sessile cells were always present in the cultures, but they never became dominant under the culture conditions. Time-lapse video microscopic observations revealed that after cell division of a sessile cell, one daughter cell became motile, while the other remained sessile. According to ultrastructural characteristics of the pyrenoids and nucleomorphs, the new chlorarachniophyte strain belongs to the genus Gymnochlora.
    [Show full text]
  • VII EUROPEAN CONGRESS of PROTISTOLOGY in Partnership with the INTERNATIONAL SOCIETY of PROTISTOLOGISTS (VII ECOP - ISOP Joint Meeting)
    See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/283484592 FINAL PROGRAMME AND ABSTRACTS BOOK - VII EUROPEAN CONGRESS OF PROTISTOLOGY in partnership with THE INTERNATIONAL SOCIETY OF PROTISTOLOGISTS (VII ECOP - ISOP Joint Meeting) Conference Paper · September 2015 CITATIONS READS 0 620 1 author: Aurelio Serrano Institute of Plant Biochemistry and Photosynthesis, Joint Center CSIC-Univ. of Seville, Spain 157 PUBLICATIONS 1,824 CITATIONS SEE PROFILE Some of the authors of this publication are also working on these related projects: Use Tetrahymena as a model stress study View project Characterization of true-branching cyanobacteria from geothermal sites and hot springs of Costa Rica View project All content following this page was uploaded by Aurelio Serrano on 04 November 2015. The user has requested enhancement of the downloaded file. VII ECOP - ISOP Joint Meeting / 1 Content VII ECOP - ISOP Joint Meeting ORGANIZING COMMITTEES / 3 WELCOME ADDRESS / 4 CONGRESS USEFUL / 5 INFORMATION SOCIAL PROGRAMME / 12 CITY OF SEVILLE / 14 PROGRAMME OVERVIEW / 18 CONGRESS PROGRAMME / 19 Opening Ceremony / 19 Plenary Lectures / 19 Symposia and Workshops / 20 Special Sessions - Oral Presentations / 35 by PhD Students and Young Postdocts General Oral Sessions / 37 Poster Sessions / 42 ABSTRACTS / 57 Plenary Lectures / 57 Oral Presentations / 66 Posters / 231 AUTHOR INDEX / 423 ACKNOWLEDGMENTS-CREDITS / 429 President of the Organizing Committee Secretary of the Organizing Committee Dr. Aurelio Serrano
    [Show full text]