DOCSLIB.ORG

Protista and the Origin of Metazoans

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Protista and the Origin of Metazoans SEM of Paramecium Protista and the Origin of Metazoans Goals: Introduction Review characteristics of single I. Body Plan cell body plan A. S.A./Volume Constraint Explore the limitations of life B. Reynolds number Kingdom as a single cell II. Important Protists Protista Learn some of the ways in which protists are important A. In food webs B. Agents of disease Evaluate evidence for the origin of animals from protist ancestors III. Origin of Metazoans Evidence for colonial origin and metazoan ancestors (Based on Textbook Chapter 3) Protista Defy Tidy Definition: Body plan characterized by: - >10 phyla, believed by some that they should be A. Unicellularity (most) classified as Kingdoms B. Small Size (< 5-250 µm) - Among them are the C. Lacking Organ Systems ancestors of multicell (including a nervous system) organisms including animals. Each individual is a cell that is functionally more versatile than any single cell from a multicell organism Means of locomotion and associated structures are no longer Most Common TYPES of Protista: considered key characters in establishing the phylongeny (evolutionary relatedness) of Protista. Ciliates (Phylum Ciliophora): externally ciliated Sarcodinids: 4 phyla of amoeboid types Paramecium (Amoebas, foramenifera, radiozoans, heliozoans) Ciliates foramenifera dinoflagellate Flagellates: several phyla of flagella-bearing Euglenoid types, including many photosynthetic forms and Some important parasitic forms Spore-Formers: Phylum Apicomplexa and other Didinium very important parasitic forms Amoeboid Flagellated 1 Kingdom Protozoa Picture of the Day Giant foraminifera Phylogeny is Complicated/Unresolved - Eats crustaceans -important Notodendrodes antarctikus predator Alveolate Amoeboid Flagellated - Makes a sand case; selects grains Protozoa of only certain sizes from Protozoa Protozoa 1 sediments….. Central to discussion Inch about intelligence EUGLENOZOA (2.5 cm) PH CILIOPHORA - Charles Darwin had this to say: GRANULORETICULOSA trypanosomes - (ciliates) (foramenifera) euglinids "The case of the three species of RADIOZOA protozoan (I forget the names) which DINOZOA trichomonads apparently select differently sized (dinoflagellates) (radiolarians) grains of sand, etc., is almost the most Giardia wonderful fact I ever heard of. One APICOMPLEXA ACANTHARIA cannot believe that they have mental (coccidians (actinarians) power enough to do so… “ e.g. Plasmodium) HELIOZOA (heliozoans) See pie chart ad taxonomic detail on pg 75 http://kabinetofcuriosities.blogspot.com/2010/02/tree- foraminifera.html SOFI Comments… Kingdom Protozoa Too much phylogeny and evolution! This is not necessarily Phylogeny is Complicated/Unresolved interesting to students. I never knew what we had to learn and what he thought was just cool to Alveolate Amoeboid Flagellated know Protozoa Protozoa Protozoa I will not need to know most of the things i learned, but i did learn things other than what i knew before. It was hard for me to get EUGLENOZOA PH CILIOPHORA interested and excited, but the teacher was GRANULORETICULOSA trypanosomes (ciliates) (foramenifera) euglinids This was one of my harder classes this semester. The tests were quite RADIOZOA DINOZOA trichomonads difficult and I really had to study to do well on them. (dinoflagellates) (radiolarians) Giardia APICOMPLEXA ACANTHARIA The grading is very fair. I really appreciate classes where if you put in (coccidians (actinarians) the effort you can do well and the professor doesn't try to trick you e.g. Plasmodium) with weird questions etc. on tests. It's fair that everything on the HELIOZOA tests we have gone over in class, it's just the students job to decide if (heliozoans) they want to study it or not. I wish more of my classes were like this. See pie chart ad taxonomic detail on pg 75 Protista and the Origin of Metazoans I. Protistan Body Plan is Characterized by Introduction -- Primarily unicellular I. Body Plan -- Small, 5 -300 µm A. S.A./Volume Constraint -- Lack organs B. Reynolds number (Lack a nervous system) II. Important Protists A. In food webs B. Agents of disease What constraints does the small unicellular body plan impose on the biology of protistans? III. Origin of Metazoans Evidence for colonial origin and metazoan ancestors 2 S.A./Vol relationship imposes a limit on cell size As a cell increases in size, exchange with the environment Some Amebas becomes more difficult partly solve 1 this problem Inch L Surface Area ~ L2 (2.5 cm) Volume ~ L3 Therefore S.A./V declines L as L increases Cytoplasmic streaming provides continuous mixing or circulation of the cytosol Small Size also affects scaling of physical forces Re = velocity x length of the organism Viscocity of Medium Balance of inertia and drag When Re is high, drag is relatively negligible on a moving organism (example, Re is 30,000 for a dragonfly in flight) Depends on the size and velocity of the organism When Re is low, drag forces dominate movement and on the viscocity of the medium. (example, Re for a protist could be <0.1) Expressed as Reynolds Number (Re) Re = velocity x length of the organism In what way would low Reynolds Viscocity of Medium numbers affect the ecology of protists? Re = vel x L Vis Re = velocity x length of the organism Viscocity of Medium What is life like at Low Reynolds numbers?? -- no inertia -- force of gravity balanced by viscocity -- yet ciliates travel 2 mm per sec. (8 body lengths) -- feeding also affected Vorticella feeding 3 Re = vel x L I. Protistan Body Plan is Characterized by Vis -- Primarily unicellular -- Small, 5 -300 µm Viscous forces can -- Lack organs also be important in (Lack a nervous system) air but the medium is not very dense what conditions will What constraints does the small unicellular produce a low Re??? body plan impose on the biology of protistans? Midge Anterior Organelles are the Food functional equivalents of vacuole organs. Oral nuclei groove Organelles not generally found in metazoans Cyto- - contractile vacuoles stome - trichocysts - toxicysts Fig 3.19 contractile Posterior http://www.youtube.com/watch?v=hSFJ- Paramecium Feeding vacuole Contraction spnn6c&NR=1 II. Importance of Protozoa Spasmin filaments The spasmoneme is a biological A. Major role in ecosystems as decomposers, food source for spring organelle. Contraction is metazoans completed in 2 ms at speeds up to 8 cm/sec and is triggered B. Responsible for a large number of human ailments, including by Ca++ activated interactions malaria, dysentery, sleeping sickness along the length of the supramolecular structure. The reaction does not require ATP C. Provided biologists with outstanding material for genetic, physiological and other studies. 4 Chagas’ Disease Trypanosoma cruzi Protista and the Origin of Metazoans (American trypanosome) Introduction Vector is a biting bug; parasite infects I. Body Plan bug through feces A. S.A./Volume Constraint Affects the nervous system and the heart; can be fatal B. Reynolds number Child with Acute infection II. Important Protists A. In food webs B. Agents of disease III. Origin of Metazoans Evidence for colonial origin and metazoan ancestors Metazoa arose from Protozoa sometime before the Cambrian 1200-600 mya What is a “metazoan”?? Which protozoan group was the ancestor?? Eukaryotic and multicellular By what process was first metazoan formed?? Cell differentiation and coordination; more than a colony or aggregation of cells Are metazoans Monophyletic or Polyphyletic?? Layers of cells organized into “tissues” What were the first Metazoans like?? Embryonic development; gastrulation CAN WE EVER REALLY KNOW?? 3 Phyla are Possible Candidates as Basal Group of all Animals Symbiotic Hypothesis Theoretically 3 ways in which a multicellular Colonial Hypothesis organism could evolve from a protist. Cnidarians Cellularization Hypothesis Sponges Flatworms 5 Cellularization Strengths: Paramecium-flatworms are similar Weaknesses: no evidence of “compartmentalization” Strengths: Origin of Eukaryotes from prokaryotes :flatworms with complex embryology Weakness: Genetic obstacles to reproduction. How :What about Cnidaria, Sponges ?? do they integrate into a reproducing organism? Stained Paramecium showing multiple ”inclusions” Macronucleus (Haeckle’s favorite) Blastea Gastrea Strengths: models exist (Volvox, choanoflag.) : parallels animal embryology Weaknesses: ??? Similarities of Choanocytes (sponge cells) and choanoflagellates (protozoan) Choanoflagellates live as solitary and colonial forms Choanocyte Choanoflagellate 6 Model organization Eudorina Opisthokonts share: Pandorina uniflagellate (reproductive) stages with flagellum at the posterior Mitochondria with flattened, plate-like cristae Volvox Genetic Evidence (18S r-DNA) Based on sequence analyses of 5 proteins Monosiga has 86% sequence homology with animals. Mol. Biol. Evol. 23: 93-106 2006 Conclusions on Metazoan Origin Evidence best supports the colonial theory Choanoflagellate group is most likely ancestor; Evidence includes cell structure and genetic similarities a. Phylogeny based on protein domain comparisons Idea that metazoans are monophyletic is supported b-d. choanoflagellate cells bear a single Flagellum and an apical collar of actin- filled microvilli (bracket, c). D. an overlay of b-tubulin (reen), polymerized actin (red) and DNA (blue) localization reveals the position of the flagellum within the collar of microvilli. 7 .
Load more

Recommended publications
  • 1 Lessons from Simple Marine Models on the Bacterial Regulation
    bioRxiv preprint doi: https://doi.org/10.1101/211797; this version posted October 31, 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-NC-ND 4.0 International license. Lessons from simple marine models on the bacterial regulation of eukaryotic development Arielle Woznicaa and Nicole Kinga,1 a Howard Hughes Medical Institute and Department of Molecular and Cell Biology, University of California, Berkeley, California 94720, United States 1 Corresponding author, [email protected]. 1 bioRxiv preprint doi: https://doi.org/10.1101/211797; this version posted October 31, 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-NC-ND 4.0 International license. 1 Highlights 2 - Cues from environmental bacteria influence the development of many marine 3 eukaryotes 4 5 - The molecular cues produced by environmental bacteria are structurally diverse 6 7 - Eukaryotes can respond to many different environmental bacteria 8 9 - Some environmental bacteria act as “information hubs” for diverse eukaryotes 10 11 - Experimentally tractable systems, like the choanoflagellate S. rosetta, promise to 12 reveal molecular mechanisms underlying these interactions 13 14 Abstract 15 Molecular cues from environmental bacteria influence important developmental 16 decisions in diverse marine eukaryotes. Yet, relatively little is understood about the 17 mechanisms underlying these interactions, in part because marine ecosystems are 18 dynamic and complex.
    [Show full text]
  • 28-Protistsf20r.Ppt [Compatibility Mode]
    9/3/20 Ch 28: The Protists (a.k.a. Protoctists) (meet these in more detail in your book and lab) 1 Protists invent: eukaryotic cells size complexity Remember: 1°(primary) endosymbiosis? -> mitochondrion -> chloroplast genome unicellular -> multicellular 2 1 9/3/20 For chloroplasts 2° (secondary) happened (more complicated) {3°(tertiary) happened too} 3 4 Eukaryotic “supergroups” (SG; between K and P) 4 2 9/3/20 Protists invent sex: meiosis and fertilization -> 3 Life Cycles/Histories (Fig 13.6) Spores and some protists (Humans do this one) 5 “Algae” Group PS Pigments Euglenoids chl a & b (& carotenoids) Dinoflagellates chl a & c (usually) (& carotenoids) Diatoms chl a & c (& carotenoids) Xanthophytes chl a & c (& carotenoids) Chrysophytes chl a & c (& carotenoids) Coccolithophorids chl a & c (& carotenoids) Browns chl a & c (& carotenoids) Reds chl a, phycobilins (& carotenoids) Greens chl a & b (& carotenoids) (more groups exist) 6 3 9/3/20 Name word roots (indicate nutrition) “algae” (-phyt-) protozoa (no consistent word ending) “fungal-like” (-myc-) Ecological terms plankton phytoplankton zooplankton 7 SG: Excavata/Excavates “excavated” feeding groove some have reduced mitochondria (e.g.: mitosomes, hydrogenosomes) 8 4 9/3/20 SG: Excavata O: Diplomonads: †Giardia Cl: Parabasalids: Trichonympha (bk only) †Trichomonas P: Euglenophyta/zoa C: Kinetoplastids = trypanosomes/hemoflagellates: †Trypanosoma C: Euglenids: Euglena 9 SG: “SAR” clade: Clade Alveolates cell membrane 10 5 9/3/20 SG: “SAR” clade: Clade Alveolates P: Dinoflagellata/Pyrrophyta:
    [Show full text]
  • Phylogenetic Classification of Life
    Proc. Natl. Accad. Sci. USA Vol. 93, pp. 1071-1076, February 1996 Evolution Archaeal- eubacterial mergers in the origin of Eukarya: Phylogenetic classification of life (centriole-kinetosome DNA/Protoctista/kingdom classification/symbiogenesis/archaeprotist) LYNN MARGULIS Department of Biology, University of Massachusetts, Amherst, MA 01003-5810 Conitribluted by Lynnl Marglulis, September 15, 1995 ABSTRACT A symbiosis-based phylogeny leads to a con- these features evolved in their ancestors by inferable steps (4, sistent, useful classification system for all life. "Kingdoms" 20). rRNA gene sequences (Trichomonas, Coronympha, Giar- and "Domains" are replaced by biological names for the most dia; ref. 11) confirm these as descendants of anaerobic eu- inclusive taxa: Prokarya (bacteria) and Eukarya (symbiosis- karyotes that evolved prior to the "crown group" (12)-e.g., derived nucleated organisms). The earliest Eukarya, anaero- animals, fungi, or plants. bic mastigotes, hypothetically originated from permanent If eukaryotes began as motility symbioses between Ar- whole-cell fusion between members of Archaea (e.g., Thermo- chaea-e.g., Thermoplasma acidophilum-like and Eubacteria plasma-like organisms) and of Eubacteria (e.g., Spirochaeta- (Spirochaeta-, Spirosymplokos-, or Diplocalyx-like microbes; like organisms). Molecular biology, life-history, and fossil ref. 4) where cell-genetic integration led to the nucleus- record evidence support the reunification of bacteria as cytoskeletal system that defines eukaryotes (21)-then an Prokarya while
    [Show full text]
  • Plant Evolution an Introduction to the History of Life
    Plant Evolution An Introduction to the History of Life KARL J. NIKLAS The University of Chicago Press Chicago and London CONTENTS Preface vii Introduction 1 1 Origins and Early Events 29 2 The Invasion of Land and Air 93 3 Population Genetics, Adaptation, and Evolution 153 4 Development and Evolution 217 5 Speciation and Microevolution 271 6 Macroevolution 325 7 The Evolution of Multicellularity 377 8 Biophysics and Evolution 431 9 Ecology and Evolution 483 Glossary 537 Index 547 v Introduction The unpredictable and the predetermined unfold together to make everything the way it is. It’s how nature creates itself, on every scale, the snowflake and the snowstorm. — TOM STOPPARD, Arcadia, Act 1, Scene 4 (1993) Much has been written about evolution from the perspective of the history and biology of animals, but significantly less has been writ- ten about the evolutionary biology of plants. Zoocentricism in the biological literature is understandable to some extent because we are after all animals and not plants and because our self- interest is not entirely egotistical, since no biologist can deny the fact that animals have played significant and important roles as the actors on the stage of evolution come and go. The nearly romantic fascination with di- nosaurs and what caused their extinction is understandable, even though we should be equally fascinated with the monarchs of the Carboniferous, the tree lycopods and calamites, and with what caused their extinction (fig. 0.1). Yet, it must be understood that plants are as fascinating as animals, and that they are just as important to the study of biology in general and to understanding evolutionary theory in particular.
    [Show full text]
  • There Is Not a Latin Root Word Clear Your Desk Protist Quiz Grade Quiz
    There is not a Latin Root Word Clear your desk Protist Quiz Grade Quiz Malaria Fever Wars Classification Kingdom Protista contains THREE main groups of organisms: 1. Protozoa: “animal-like protists” 2. Algae: “plant-like protists” 3. Slime & Water Molds: “fungus-like protists” Basics of Protozoa Unicellular Eukaryotic unlike bacteria 65, 000 different species Heterotrophic Free-living (move in aquatic environments) or Parasitic Habitats include oceans, rivers, ponds, soil, and other organisms. Protozoa Reproduction ALL protozoa can use asexual reproduction through binary fission or multiple fission FEW protozoa reproduce sexually through conjugation. Adaptation Special Protozoa Adaptations Eyespot: detects changes in the quantity/ quality of light, and physical/chemical changes in their environment Cyst: hardened external covering that protects protozoa in extreme environments. Basics of Algae: “Plant-like” protists. MOST unicellular; SOME multicellular. Make food by photosynthesis (“autotrophic prostists”). Were classified as plants, BUT… – Lack tissue differentiation- NO roots, stems, leaves, etc. – Reproduce differently Most algal cells have pyrenoids (organelles that make and store starch) Can use asexual or sexual reproduction. Algae Structure: Thallus: body portion; usually haploid Body Structure: 1) unicellular: single-celled; aquatic (Ex.phytoplankton, Chlamydomonas) 2) colonial: groups of coordinated cells; “division of labor” (Ex. Volvox) 3) filamentous: rod-shaped thallus; some anchor to ocean bottom (Ex. Spyrogyra) 4) multicellular: large, complex, leaflike thallus (Ex. Macrocystis- giant kelp) Basics of Fungus-like Protists: Slime Molds: Water Molds: Once classified as fungi Fungus-like; composed of Found in damp soil, branching filaments rotting logs, and other Commonly freshwater; decaying matter. some in soil; some Some white, most yellow parasites.
    [Show full text]
  • Wrc Research Report No. 131 Effects of Feedlot Runoff
    WRC RESEARCH REPORT NO. 131 EFFECTS OF FEEDLOT RUNOFF ON FREE-LIVING AQUATIC CILIATED PROTOZOA BY Kenneth S. Todd, Jr. College of Veterinary Medicine Department of Veterinary Pathology and Hygiene University of Illinois Urbana, Illinois 61801 FINAL REPORT PROJECT NO. A-074-ILL This project was partially supported by the U. S. ~epartmentof the Interior in accordance with the Water Resources Research Act of 1964, P .L. 88-379, Agreement No. 14-31-0001-7030. UNIVERSITY OF ILLINOIS WATER RESOURCES CENTER 2535 Hydrosystems Laboratory Urbana, Illinois 61801 AUGUST 1977 ABSTRACT Water samples and free-living and sessite ciliated protozoa were col- lected at various distances above and below a stream that received runoff from a feedlot. No correlation was found between the species of protozoa recovered, water chemistry, location in the stream, or time of collection. Kenneth S. Todd, Jr'. EFFECTS OF FEEDLOT RUNOFF ON FREE-LIVING AQUATIC CILIATED PROTOZOA Final Report Project A-074-ILL, Office of Water Resources Research, Department of the Interior, August 1977, Washington, D.C., 13 p. KEYWORDS--*ciliated protozoa/feed lots runoff/*water pollution/water chemistry/Illinois/surface water INTRODUCTION The current trend for feeding livestock in the United States is toward large confinement types of operation. Most of these large commercial feedlots have some means of manure disposal and programs to prevent runoff from feed- lots from reaching streams. However, there are still large numbers of smaller feedlots, many of which do not have adequate facilities for disposal of manure or preventing runoff from reaching waterways. The production of wastes by domestic animals was often not considered in the past, but management of wastes is currently one of the largest problems facing the livestock industry.
    [Show full text]
  • An Evolutionary Switch in the Specificity of an Endosomal CORVET Tether Underlies
    bioRxiv preprint doi: https://doi.org/10.1101/210328; this version posted October 27, 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-NC-ND 4.0 International license. Title: An evolutionary switch in the specificity of an endosomal CORVET tether underlies formation of regulated secretory vesicles in the ciliate Tetrahymena thermophila Daniela Sparvolia, Elisabeth Richardsonb*, Hiroko Osakadac*, Xun Land,e*, Masaaki Iwamotoc, Grant R. Bowmana,f, Cassandra Kontura,g, William A. Bourlandh, Denis H. Lynni,j, Jonathan K. Pritchardd,e,k, Tokuko Haraguchic,l, Joel B. Dacksb, and Aaron P. Turkewitza th a Department of Molecular Genetics and Cell Biology, The University of Chicago, 920 E 58 Street, Chicago IL USA b Department of Cell Biology, University of Alberta, Canada c Advanced ICT Research Institute, National Institute of Information and Communications Technology (NICT), Kobe 651-2492, Japan. d Department of Genetics, Stanford University, Stanford, CA, 94305 e Howard Hughes Medical Institute, Stanford University, Stanford, CA 94305 f current affiliation: Department of Molecular Biology, University of Wyoming, Laramie g current affiliation: Department of Genetics, Yale University School of Medicine, New Haven, CT 06510 h Department of Biological Sciences, Boise State University, Boise ID 83725-1515 I Department of Integrative Biology, University of Guelph, Guelph ON N1G 2W1, Canada j current affiliation: Department of Zoology, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada k Department of Biology, Stanford University, Stanford, CA, 94305 l Graduate School of Frontier Biosciences, Osaka University, Suita 565-0871, Japan.
    [Show full text]
  • Bacterial Cues Regulate Multicellular Development and Mating in the Choanoflagellate, S
    Bacterial cues regulate multicellular development and mating in the choanoflagellate, S. rosetta By Arielle Woznica A dissertation submitted in partial satisfaction of the requirements for the degree of Doctor of Philosophy in Molecular and Cell Biology in the Graduate Division of the University of California, Berkeley Committee in charge: Professor Nicole King, Chair Professor Russell Vance Professor Diana Bautista Professor Brian Staskawicz Spring 2017 Abstract Bacterial cues regulate multicellular development and mating in the choanoflagellate, S. rosetta By Arielle Woznica Doctor of Philosophy in Molecular and Cell Biology University of California, Berkeley Professor Nicole King, Chair Animals first diverged from their unicellular ancestors in oceans dominated by bacteria, and have lived in close association with bacteria ever since. Interactions with bacteria critically shape diverse aspects of animal biology today, including developmental processes that were long thought to be autonomous. Yet, the multicellularity of animals and the often-complex communities of bacteria with which they are associated make it challenging to characterize the mechanisms underlying many bacterial-animal interactions. Thus, developing experimentally tractable host-microbe model systems will be essential for revealing the molecules and mechanisms by which bacteria influence animal development. The choanoflagellate Salpingoeca rosetta, one of the closest living relatives of animals, has emerged as an attractive model for studying host-microbe interactions. Like all choanoflagellates, S. rosetta feeds on bacteria; however, we have found that interactions between S. rosetta and bacteria extend beyond those of predator and prey. In fact, two key transitions in the life history of S. rosetta, multicellular “rosette” development and sexual reproduction, are regulated by environmental bacteria.
    [Show full text]
  • The Plankton Lifeform Extraction Tool: a Digital Tool to Increase The
    Discussions https://doi.org/10.5194/essd-2021-171 Earth System Preprint. Discussion started: 21 July 2021 Science c Author(s) 2021. CC BY 4.0 License. Open Access Open Data The Plankton Lifeform Extraction Tool: A digital tool to increase the discoverability and usability of plankton time-series data Clare Ostle1*, Kevin Paxman1, Carolyn A. Graves2, Mathew Arnold1, Felipe Artigas3, Angus Atkinson4, Anaïs Aubert5, Malcolm Baptie6, Beth Bear7, Jacob Bedford8, Michael Best9, Eileen 5 Bresnan10, Rachel Brittain1, Derek Broughton1, Alexandre Budria5,11, Kathryn Cook12, Michelle Devlin7, George Graham1, Nick Halliday1, Pierre Hélaouët1, Marie Johansen13, David G. Johns1, Dan Lear1, Margarita Machairopoulou10, April McKinney14, Adam Mellor14, Alex Milligan7, Sophie Pitois7, Isabelle Rombouts5, Cordula Scherer15, Paul Tett16, Claire Widdicombe4, and Abigail McQuatters-Gollop8 1 10 The Marine Biological Association (MBA), The Laboratory, Citadel Hill, Plymouth, PL1 2PB, UK. 2 Centre for Environment Fisheries and Aquacu∑lture Science (Cefas), Weymouth, UK. 3 Université du Littoral Côte d’Opale, Université de Lille, CNRS UMR 8187 LOG, Laboratoire d’Océanologie et de Géosciences, Wimereux, France. 4 Plymouth Marine Laboratory, Prospect Place, Plymouth, PL1 3DH, UK. 5 15 Muséum National d’Histoire Naturelle (MNHN), CRESCO, 38 UMS Patrinat, Dinard, France. 6 Scottish Environment Protection Agency, Angus Smith Building, Maxim 6, Parklands Avenue, Eurocentral, Holytown, North Lanarkshire ML1 4WQ, UK. 7 Centre for Environment Fisheries and Aquaculture Science (Cefas), Lowestoft, UK. 8 Marine Conservation Research Group, University of Plymouth, Drake Circus, Plymouth, PL4 8AA, UK. 9 20 The Environment Agency, Kingfisher House, Goldhay Way, Peterborough, PE4 6HL, UK. 10 Marine Scotland Science, Marine Laboratory, 375 Victoria Road, Aberdeen, AB11 9DB, UK.
    [Show full text]
  • Kingdom Animalia: Phylum Summary Table
    KINGDOM ANIMALIA: PHYLUM SUMMARY TABLE Phylum PORIFERA CNIDARIA PLATYHELMINTHES (flatworms) NEMATODA (roundworms) ANNELIDA (segmented worms) Examples Sponges Sea jellies, Hydra, coral Planaria, tapeworm Trichinella, hookworm, Earthworm, polychaete worms, colonies, sea anemones nematode leech Body type Asymmetry Radial symmetry Bilateral symmetry Bilateral symmetry Bilateral symmetry (Symmetry) Ecological roles Food source Food source Food source Food source Food source home / shelter Reef- home, protect Parasitic Parasitic Parasitic symbiotic with shores Eat dead animals – Aerate soil Aerate soil bacteria Chem. – anticancer saprophyte Breakdown material Breakdown material Body organization 2 germ layers 2 layers: ecto & endo 3 layers: ectoderm, mesoderm, 3 layers: ectoderm, 3 layers: ectoderm, mesoderm, (# germ layers) Ectoderm, endoderm With mesoglea between endoderm mesoderm, endoderm endoderm Body cavity Acoelom Acoelom Acoelom Pseudocoelom Coelom Digestive system Filter feed: collar cells, Gastrovascular cavity, Mouth and gastrovascular Complete digestive Complete digestive system: food vacuoles, mouth, and cavity system: mouth & anus mouth & anus osculum nematocysts to capture food Mouth also serves as anus Special organs Special organs Reproduction Sexual: Sexual: male & female Sexual: hermaphroditic – Sexual: separate sexes = Sexual: hermaphroditic – heramaphroditic – medusa – gametes fuse cross fertilization dioecious cross fertilization gametes released in H2O Asexual: budding, Asexual: fragmentation Asexual: budding, regeneration
    [Show full text]
  • Ecophysiology of the Brine Dinoflagellate, Polarella Glacialis
    Ecophysiology of the brine dinoflagellate, Po/are/la glacialis, and Antarctic Fast Ice Brine Communities by o-<cl. <?~(:;:;V Paul Thomson B.App.Sci. Grad.Dip ASOS (Hons) ADARM Submitted in fulfilment of the requirements for the degree of Doctor of Philosophy Institute of Antarctic and Southern Ocean Studies University of Tasmania Hobart February,2000 Declaration This is to certify that the material composing this thesis has never been accepted for any other degree or award in any other tertiary institution and, to the best of my knowledge and belief, is soley the work of the author, and contains no material previously published or written by another person, except where due reference is made in the text. Paul Gerard Thomson Authority of Access This thesis may be made available for loan and limited copying in accordance with the Copyright Act 1968. ~ Paul Gerard Thomson ·' i Abstract Extremes in salinity and temperature and high levels of incident ultraviolet radiation (UVR) characterise the brine pockets and channels of upper Antarctic fast ice. Data on the composition and distribution of the microbial community inhabiting this environment is limited. Furthermore, how this community tolerates the immoderate physical and chemical parameters of the upper ice brine is poorly understood. The microbial community in the Davis upper fast ice consists of cryo- and halotolerant autotrophic flagellates, a few diatoms, one ciliate species and several heterotrophic species. Small autotrophic dinoflagellates and chrysophytes dominate a community containing greater flagellate diversity than previously reported. A cryptomonad and two species of Pyramimonas are reported for the first time. The abundant dinoflagellate of Davis fast ice, identified using molecular taxonomy, is Polarella glacialis Montresor et al.
    [Show full text]
  • Sak/Plk4 and Mitotic Fidelity
    Oncogene (2005) 24, 306–312 & 2005 Nature Publishing Group All rights reserved 0950-9232/05 $30.00 www.nature.com/onc Sak/Plk4 and mitotic fidelity Carol J Swallow1,2, Michael A Ko1,2, Najeeb U Siddiqui1,3,4, John W Hudson5 and James W Dennis*,1,3,4 1Samuel Lunenfeld Research Institute, Mount Sinai Hospital, 600 University Ave. R988, Toronto, Ontario, Canada M5G 1X5; 2Department of Surgery, University of Toronto, Ontario, Canada; 3Department of Microbiology and Medical Genetics, University of Toronto, Ontario, Canada; 4Department of Laboratory Medicine and Pathobiology, University of Toronto, Ontario, Canada; 5Department of Biological Sciences, University of Windsor, Ontario, Canada Sak/Plk4 differs from other polo-like kinases in having (Fernebro et al., 2002). Mutation of classical tumor only a single polo box, which assumes a novel dimer fold suppressor genes follows the Knudsen 2-hit model, that localizes to the nucleolus, centrosomes and the whereby loss of the wild-type allele as a ‘second hit’ cleavage furrow.Sak expression increases gradually in S frequently results in relaxed cellular growth controls through M phase, and Sak is destroyed by APC/C (Knudson, 1971). Inherited cancer syndromes such as dependent proteolysis.Sak-deficient mouse embryos Li-Fraumeni (p53, Chk2) and ataxia telangiectasia arrest at E7.5 and display an increased incidence of (ATM) are examples of autosomal recessive mutations apoptosis and anaphase arrest.Sak þ /À mice are haploin- in checkpoint proteins that normally delay the cell cycle sufficient for tumor suppression, with spontaneous tumors in response to DNA damage and environmental stresses developing primarily in the liver with advanced age.
    [Show full text]