DOCSLIB.ORG

Dissecting the Molecular Interplay Between Tomato Spotted Wilt Virus and the Insect Vector, Frankliniella Occidentalis

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Dissecting the Molecular Interplay Between Tomato Spotted Wilt Virus and the Insect Vector, Frankliniella Occidentalis DISSECTING THE MOLECULAR INTERPLAY BETWEEN TOMATO SPOTTED WILT VIRUS AND THE INSECT VECTOR, FRANKLINIELLA OCCIDENTALIS by ISMAEL E. BADILLO VARGAS B.S., University of Puerto Rico – Mayagüez, 2006 M.S., University of Wisconsin – Madison, 2008 AN ABSTRACT OF A DISSERTATION submitted in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Department of Plant Pathology College of Agriculture KANSAS STATE UNIVERSITY Manhattan, Kansas 2014 Abstract The Bunyaviridae is a family of animal and plant viruses that pose a threat to human, animal, and plant health worldwide. In nature, the dissemination of these viruses is dependent on arthropod vectors (genera Orthobunyavirus, Nairovirus, Phlebovirus, and Tospovirus) or rodent vectors (genus Hantavirus). The genus Tospovirus is the only one within this virus family that is composed of plant-infecting viruses transmitted by thrips. Tomato spotted wilt virus (TSWV), the type species of the Tospovirus genus, is one of the ten most devastating plant viruses known. It is most efficiently transmitted by the western flower thrips, Frankliniella occidentalis Pergande, in a persistant propagative manner. The insect molecules associated with virus infection and transmission by the thrips vector remain unidentified to date. The aim of this work was to identify F. occidentalis larval thrips proteins that are differentially expressed during TSWV infection of the insect vector and those that directly interact with TSWV. To achieve these goals, I used two-dimensional (2-D) gel electrophoresis and mass spectrometry coupled with Mascot searches. I identified 26 protein spots that displayed differential abundances in response to TSWV infection, which contained 37 proteins. Sixty two percent of these proteins were down-regulated by the viral infection demonstrating a complex response. Moreover, 8 and 11 protein spots that directly interacted with purified TSWV virions and a TSWV glycoprotein (GN), respectively, were identified in overlay assays of larval thrips proteins resolved by 2-D gel electrophoresis. A total of five proteins were identified from these spots. These interacting proteins might play roles in attachment and entry, endocytosis/exocytosis, and escape from different tissues for transmission to occur. Injection of double-stranded RNA (dsRNA) into adult female thrips triggered an RNAi response that resulted in 23% reduction of the target gene transcript level. This significant reduction resulted in increased mortality and decreased fertility compared to insects injected with control dsRNA or water and non-injected insects as well. The work presented here provides new insights on the molecular basis of this virus-vector interaction and describes new tools to conduct functional genomic assays to study gene function and design control strategies of F. occidentalis. DISSECTING THE MOLECULAR INTERPLAY BETWEEN TOMATO SPOTTED WILT VIRUS AND THE INSECT VECTOR, FRANKLINIELLA OCCIDENTALIS by ISMAEL E. BADILLO VARGAS B.S., University of Puerto Rico – Mayagüez, 2006 M.S., University of Wisconsin – Madison, 2008 A DISSERTATION submitted in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Department of Plant Pathology College of Agriculture KANSAS STATE UNIVERSITY Manhattan, Kansas 2014 Approved by: Major Professor Anna E. Whitfield Copyright ISMAEL E. BADILLO VARGAS 2014 Abstract The Bunyaviridae is a family of animal and plant viruses that pose a threat to human, animal, and plant health worldwide. In nature, the dissemination of these viruses is dependent on arthropod vectors (genera Orthobunyavirus, Nairovirus, Phlebovirus, and Tospovirus) or rodent vectors (genus Hantavirus). The genus Tospovirus is the only one within this virus family that is composed of plant-infecting viruses transmitted by thrips. Tomato spotted wilt virus (TSWV), the type species of the Tospovirus genus, is one of the ten most devastating plant viruses known. It is most efficiently transmitted by the western flower thrips, Frankliniella occidentalis Pergande, in a persistant propagative manner. The insect molecules associated with virus infection and transmission by the thrips vector remain unidentified to date. The aim of this work was to identify F. occidentalis larval thrips proteins that are differentially expressed during TSWV infection of the insect vector and those that directly interact with TSWV. To achieve these goals, I used two-dimensional (2-D) gel electrophoresis and mass spectrometry coupled with Mascot searches. I identified 26 protein spots that displayed differential abundances in response to TSWV infection, which contained 37 proteins. Sixty two percent of these proteins were down-regulated by the viral infection demonstrating a complex response. Moreover, 8 and 11 protein spots that directly interacted with purified TSWV virions and a TSWV glycoprotein (GN), respectively, were identified in overlay assays of larval thrips proteins resolved by 2-D gel electrophoresis. A total of five proteins were identified from these spots. These interacting proteins might play roles in attachment and entry, endocytosis/exocytosis, and escape from different tissues for transmission to occur. Injection of double-stranded RNA (dsRNA) into adult female thrips triggered an RNAi response that resulted in 23% reduction of the target gene transcript level. This significant reduction resulted in increased mortality and decreased fertility compared to insects injected with control dsRNA or water and non-injected insects as well. The work presented here provides new insights on the molecular basis of this virus-vector interaction and describes new tools to conduct functional genomic assays to study gene function and design control strategies of F. occidentalis. Table of Contents List of Figures ................................................................................................................................ ix List of Tables ................................................................................................................................. xi Acknowledgements ....................................................................................................................... xii Dedication .................................................................................................................................... xiv Chapter 1 - Introduction and Literature Review ............................................................................. 1 Introduction ................................................................................................................................. 1 Literature Review ....................................................................................................................... 3 Family Bunyaviridae ............................................................................................................... 3 Genus Tospovirus .................................................................................................................... 4 Tomato spotted wilt virus ........................................................................................................ 6 The Thysanoptera, Frankliniella occidentalis and other thrips vector species..................... 10 Tomato spotted wilt virus-Frankliniella occidentalis interaction ......................................... 12 Responses of insects to viral infections ................................................................................ 17 Figures and Tables .................................................................................................................... 23 Chapter 2 - Proteomic analysis of Frankliniella occidentalis and differentially expressed proteins in response to Tomato spotted wilt virus infection ................................................................ 32 Abstract ..................................................................................................................................... 32 Introduction ............................................................................................................................... 32 Results ....................................................................................................................................... 36 Characterization of the larval thrips proteome ...................................................................... 36 Identification of differentially expressed proteins in response to virus infection ................. 37 Discussion ................................................................................................................................. 38 Materials and Methods .............................................................................................................. 45 Frankliniella occidentalis cultures........................................................................................ 45 Collection and protein extraction from healthy larval thrips for proteomic analysis ........... 45 Two-dimensional gel electrophoresis and MALDI-TOF/TOF mass spectrometry .............. 46 Protein identification ............................................................................................................. 47 TSWV maintenance .............................................................................................................. 48 vi Acquisition efficiency of TSWV-exposed L1 thrips ............................................................ 48 Sample preparation for proteomic
Load more

Recommended publications
  • Using Cell Lines to Study Factors Affecting Transmission of Fish Viruses
    Using cell lines to study factors affecting transmission of fish viruses by Phuc Hoang Pham A thesis presented to the University of Waterloo in fulfillment of the thesis requirement for the degree of Doctor of Philosophy in Biology Waterloo, Ontario, Canada, 2014 ©Phuc Hoang Pham 2014 AUTHOR'S DECLARATION I hereby declare that I am the sole author of this thesis. This is a true copy of the thesis, including any required final revisions, as accepted by my examiners. I understand that my thesis may be made electronically available to the public. ii ABSTRACT Factors that can influence the transmission of aquatic viruses in fish production facilities and natural environment are the immune defense of host species, the ability of viruses to infect host cells, and the environmental persistence of viruses. In this thesis, fish cell lines were used to study different aspects of these factors. Five viruses were used in this study: viral hemorrhagic septicemia virus (VHSV) from the Rhabdoviridae family; chum salmon reovirus (CSV) from the Reoviridae family; infectious pancreatic necrosis virus (IPNV) from the Birnaviridae family; and grouper iridovirus (GIV) and frog virus-3 (FV3) from the Iridoviridae family. The first factor affecting the transmission of fish viruses examined in this thesis is the immune defense of host species. In this work, infections of marine VHSV-IVa and freshwater VHSV-IVb were studied in two rainbow trout cell lines, RTgill-W1 from the gill epithelium, and RTS11 from spleen macrophages. RTgill-W1 produced infectious progeny of both VHSV-IVa and -IVb. However, VHSV-IVa was more infectious than IVb toward RTgill-W1: IVa caused cytopathic effects (CPE) at a lower viral titre, elicited CPE earlier, and yielded higher titres.
    [Show full text]
  • Drosophila Biology in the Genomic Age
    Copyright Ó 2007 by the Genetics Society of America DOI: 10.1534/genetics.107.074112 Drosophila Biology in the Genomic Age Therese Ann Markow*,1 and Patrick M. O’Grady† *Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, Arizona 85721 and †Division of Organisms and the Environment, University of California, Berkeley, California 94720 Manuscript received April 9, 2007 Accepted for publication May 10, 2007 ABSTRACT Over the course of the past century, flies in the family Drosophilidae have been important models for understanding genetic, developmental, cellular, ecological, and evolutionary processes. Full genome se- quences from a total of 12 species promise to extend this work by facilitating comparative studies of gene expression, of molecules such as proteins, of developmental mechanisms, and of ecological adaptation. Here we review basic biological and ecological information of the species whose genomes have recently been completely sequenced in the context of current research. F most biologists were given one wish to facilitate their several hundred taxa that await description. Most of I research, many would opt for the fully sequenced these taxa belong to one of two major subgenera: genome of their focal taxon. Others might ask for a Sophophora and Drosophila. Figure 1 shows the phylo- diverse array of genetic tools around which they could genetic relationships and divergence times of the 12 design experiments to answer evolutionary, developmen- species for which whole-genome sequences are now tal, behavioral, or ecological questions. With the recent available. The 12 species with sequenced genomes completion of full genome sequences from 12 species, represent a gradient of evolutionary distances from D.
    [Show full text]
  • Journal of Virology
    JOURNAL OF VIROLOGY Volume 80 March 2006 No. 6 SPOTLIGHT Articles of Significant Interest Selected from This Issue by 2587–2588 the Editors STRUCTURE AND ASSEMBLY Crystal Structure of the Oligomerization Domain of the Haitao Ding, Todd J. Green, 2808–2814 Phosphoprotein of Vesicular Stomatitis Virus Shanyun Lu, and Ming Luo Subcellular Localization of Hepatitis C Virus Structural Yves Rouille´, Franc¸ois Helle, David 2832–2841 Proteins in a Cell Culture System That Efficiently Replicates Delgrange, Philippe Roingeard, the Virus Ce´cile Voisset, Emmanuelle Blanchard, Sandrine Belouzard, Jane McKeating, Arvind H. Patel, Geert Maertens, Takaji Wakita, Czeslaw Wychowski, and Jean Dubuisson A Small Loop in the Capsid Protein of Moloney Murine Marcy R. Auerbach, Kristy R. 2884–2893 Leukemia Virus Controls Assembly of Spherical Cores Brown, Artem Kaplan, Denise de Las Nueces, and Ila R. Singh Identification of the Nucleocapsid, Tegument, and Envelope Jyh-Ming Tsai, Han-Ching Wang, 3021–3029 Proteins of the Shrimp White Spot Syndrome Virus Virion Jiann-Horng Leu, Andrew H.-J. Wang, Ying Zhuang, Peter J. Walker, Guang-Hsiung Kou, and Chu-Fang Lo GENOME REPLICATION AND REGULATION OF VIRAL GENE EXPRESSION Epitope Mapping of Herpes Simplex Virus Type 2 gH/gL Tina M. Cairns, Marie S. Shaner, Yi 2596–2608 Defines Distinct Antigenic Sites, Including Some Associated Zuo, Manuel Ponce-de-Leon, with Biological Function Isabelle Baribaud, Roselyn J. Eisenberg, Gary H. Cohen, and J. Charles Whitbeck The ␣-TIF (VP16) Homologue (ETIF) of Equine Jens von Einem, Daniel 2609–2620 Herpesvirus 1 Is Essential for Secondary Envelopment Schumacher, Dennis J. O’Callaghan, and Virus Egress and Nikolaus Osterrieder Suppression of Viral RNA Recombination by a Host Chi-Ping Cheng, Elena Serviene, 2631–2640 Exoribonuclease and Peter D.
    [Show full text]
  • The Retromer Is Co-Opted to Deliver Lipid Enzymes for the Biogenesis of Lipid-Enriched Tombusviral Replication Organelles
    The retromer is co-opted to deliver lipid enzymes for the biogenesis of lipid-enriched tombusviral replication organelles Zhike Fenga, Jun-ichi Inabaa, and Peter D. Nagya,1 aDepartment of Plant Pathology, University of Kentucky, Lexington, KY 40546 Edited by George E. Bruening, University of California, Davis, CA, and approved November 5, 2020 (received for review July 29, 2020) Biogenesis of viral replication organelles (VROs) is critical for repli- TBSV infections include extensive membrane contact sites (vMCSs) cation of positive-strand RNA viruses. In this work, we demonstrate and harbor numerous spherules (containing VRCs), which are that tomato bushy stunt virus (TBSV) and the closely related carna- vesicle-like invaginations in the peroxisomal membranes (8, 11–13). tion Italian ringspot virus (CIRV) hijack the retromer to facilitate A major gap in our understanding of the biogenesis of VROs, in- building VROs in the surrogate host yeast and in plants. Depletion cluding vMCSs and VRCs, is how the cellular lipid-modifying en- of retromer proteins, which are needed for biogenesis of endosomal zymes are recruited to the sites of viral replication. tubular transport carriers, strongly inhibits the peroxisome-associ- Tombusviruses belong to the large Flavivirus-like supergroup ated TBSV and the mitochondria-associated CIRV replication in yeast that includes important human, animal, and plant pathogens. in planta. and In vitro reconstitution revealed the need for the ret- Tombusviruses have a small single-component (+)RNA genome romer for the full activity of the viral replicase. The viral p33 repli- of ∼4.8 kb that codes for five proteins. Among those, there are cation protein interacts with the retromer complex, including Vps26, two essential replication proteins, namely p33 and p92pol, the Vps29, and Vps35.
    [Show full text]
  • Detection and Characterization of a Novel Marine Birnavirus Isolated from Asian Seabass in Singapore
    Chen et al. Virology Journal (2019) 16:71 https://doi.org/10.1186/s12985-019-1174-0 RESEARCH Open Access Detection and characterization of a novel marine birnavirus isolated from Asian seabass in Singapore Jing Chen1†, Xinyu Toh1†, Jasmine Ong1, Yahui Wang1, Xuan-Hui Teo1, Bernett Lee2, Pui-San Wong3, Denyse Khor1, Shin-Min Chong1, Diana Chee1, Alvin Wee1, Yifan Wang1, Mee-Keun Ng1, Boon-Huan Tan3 and Taoqi Huangfu1* Abstract Background: Lates calcarifer, known as seabass in Asia and barramundi in Australia, is a widely farmed species internationally and in Southeast Asia and any disease outbreak will have a great economic impact on the aquaculture industry. Through disease investigation of Asian seabass from a coastal fish farm in 2015 in Singapore, a novel birnavirus named Lates calcarifer Birnavirus (LCBV) was detected and we sought to isolate and characterize the virus through molecular and biochemical methods. Methods: In order to propagate the novel birnavirus LCBV, the virus was inoculated into the Bluegill Fry (BF-2) cell line and similar clinical signs of disease were reproduced in an experimental fish challenge study using the virus isolate. Virus morphology was visualized using transmission electron microscopy (TEM). Biochemical analysis using chloroform and 5-Bromo-2′-deoxyuridine (BUDR) sensitivity assays were employed to characterize the virus. Next-Generation Sequencing (NGS) was also used to obtain the virus genome for genetic and phylogenetic analyses. Results: The LCBV-infected BF-2 cell line showed cytopathic effects such as rounding and granulation of cells, localized cell death and detachment of cells observed at 3 to 5 days’ post-infection.
    [Show full text]
  • Genome-Wide Screen Identifies Host Genes Affecting Viral RNA Recombination
    Genome-wide screen identifies host genes affecting viral RNA recombination Elena Serviene, Natalia Shapka, Chi-Ping Cheng, Tadas Panavas, Bencharong Phuangrat, Jannine Baker, and Peter D. Nagy* Department of Plant Pathology, University of Kentucky, Plant Science Building, Lexington, KY 40546 Communicated by Paul Ahlquist, University of Wisconsin, Madison, WI, June 9, 2005 (received for review October 12, 2004) Rapid evolution of RNA viruses with mRNA-sense genomes is a in vitro replication͞recombination studies with a small replicon major concern to health and economic welfare because of the RNA, termed defective interfering 72 (DI-72) RNA (21, 22), devastating diseases these viruses inflict on humans, animals, and established a role for RNA sequences͞structures and viral replicase plants. To test whether host genes can affect the evolution of RNA proteins in RNA recombination. Coexpression of the replicon viruses, we used a Saccharomyces cerevisiae single-gene deletion RNA with the two essential tombusviral replicase proteins (see Fig. library, which includes Ϸ80% of yeast genes, in RNA recombination 1A) resulted in robust DI RNA replication in Saccharomyces studies based on a small viral replicon RNA derived from tomato cerevisiae (23, 24), which is a model eukaryotic host. Yeast also bushy stunt virus. The genome-wide screen led to the identifica- supported viral RNA recombination, giving rise to recombinants tion of five host genes whose absence resulted in the rapid similar to those in plants and plant protoplasts (23). Therefore, generation of new viral RNA recombinants. Thus, these genes yeast could be a useful host to study viral RNA recombination and normally suppress viral RNA recombination, but in their absence, to identify host proteins involved in this process.
    [Show full text]
  • CHARACTERIZATION of FIELD STRAINS of INFECTIOUS BURSAL DISEASE VIRUS (IBDV) USING MOLECULAR TECHNIQUES by ALEJANDRO BANDA (Under
    CHARACTERIZATION OF FIELD STRAINS OF INFECTIOUS BURSAL DISEASE VIRUS (IBDV) USING MOLECULAR TECHNIQUES by ALEJANDRO BANDA (Under the Direction of Pedro Villegas) ABSTRACT This study was aimed to apply different molecular techniques in the genotyping of field strains of infectious bursal disease virus (IBDV) currently present in the United States and in some other countries. The different techniques included the reverse transcription-polymerase chain reaction / restriction fragment length polymorphism (RT- PCR/RFLP), heteroduplex mobility assay (HMA), nucleotide and amino acid sequence analysis, and riboprobe in situ hybridization (ISH). From 150 samples analyzed from the United States, 80% exhibited RFLP identical to the variant Delaware E strain, other strains detected included Sal-1, D-78, Lukert, PBG-98, Delaware A, GLS IBDV standard challenge strain –like (STC-like). The analysis of the deduced amino acid sequence of the VP2 hypervariable region from six strains classified as Delaware variant E, revealed some amino acid substitutions that make them somewhat different from the original variant E strain isolated in the mid 1980s. The isolate 9109 was classified as a standard strain, but, it exhibited a unique RFLP pattern characterized by the presence of the Ssp I restriction site characteristic of the very virulent IBDV (vvIBDV) strains. The pathogenic properties of this isolate were compared to those of isolate 9865 (variant strain) and the Edgar strain. All three strains induced subclinical disease, however by in situ hybridization some differences in the tissue tropism were observed. The viral replication of the variant isolate 9865 was more restricted to the bursa of Fabricius. Isolate 9109 and the Edgar strain were also observed in thymus, cecal tonsils, spleen, kidney and proventriculus.
    [Show full text]
  • A Research Review on Tomato Bushy Stunt Virus Disease Complex
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by International Institute for Science, Technology and Education (IISTE): E-Journals Journal of Natural Sciences Research www.iiste.org ISSN 2224-3186 (Paper) ISSN 2225-0921 (Online) Vol.4, No.5, 2014 A Research Review on Tomato Bushy Stunt Virus Disease Complex Hafiz Husnain Nawaz, Muhammad Umer, Sadia Bano, Anam Usmani, Memoona Naseer Institute of Agricultural Sciences, University of the Punjab, Lahore *corresponding e-mail: [email protected] Abstract: Tomato Bushy Stunt Virus (TBSV) was firstly reported on tomatoes by Smith in 1935 in England. The virus belongs to genus Tombusvirus and family Tombusviridae , is a soil-borne virus with isometric particle about 30 nm in diameter. Tomato Bushy Stunt Virus can cause chlorosis, necrosis, stunting, leaf yellowing, leaf mottling, leaf crinkling and fruit setting may be reduced or become zero. These symptoms were depending upon the host morphology. Transmission of this virus is naturally through infected seeds, propagative material and manually by the use of infective cutting tools. A numbers of varieties were affected. But it’s also observed that Lycopersicon pimpinellifolium not susceptible host plant. Gel Electropherotic analysis shows that virus distantly related serologically with several other viral species in the genus Tombusvirus . In phosphotungstic acid, the particles show an angular outline and unresolved surface structure but when mounted in uranyl acetate, they exhibit a rounded outline and somewhat knobby surface and edges. The viral genome is monopartite and TBSV- Ch has been completely sequenced and shown to contain 4,776 nucleotides.
    [Show full text]
  • A-Lovisolo.Vp:Corelventura
    Acta zoologica cracoviensia, 46(suppl.– Fossil Insects): 37-50, Kraków, 15 Oct., 2003 Searching for palaeontological evidence of viruses that multiply in Insecta and Acarina Osvaldo LOVISOLO and Oscar RÖSLER Received: 31 March, 2002 Accepted for publication: 17 Oct., 2002 LOVISOLO O., RÖSLER O. 2003. Searching for palaeontological evidence of viruses that multiply in Insecta and Acarina. Acta zoologica cracoviensia, 46(suppl.– Fossil Insects): 37-50. Abstract. Viruses are known to be agents of important diseases of Insecta and Acarina, and many vertebrate and plant viruses have arthropods as propagative vectors. There is fossil evidence of arthropod pathogens for some micro-organisms, but not for viruses. Iso- lated virions would be hard to detect but, in fossil material, it could be easier to find traces of virus infection, mainly virus-induced cellular structures (VICS), easily recognisable by electron microscopy, such as virions encapsulated in protein occlusion bodies, aggregates of membrane-bounded virus particles and crystalline arrays of numerous virus particles. The following main taxa of viruses that multiply in arthropods are discussed both for some of their evolutionary aspects and for the VICS they cause in arthropods: A. dsDNA Poxviridae, Asfarviridae, Baculoviridae, Iridoviridae, Polydnaviridae and Ascoviridae, infecting mainly Lepidoptera, Hymenoptera, Coleoptera, Diptera and Acarina; B. ssDNA Parvoviridae, infecting mainly Diptera and Lepidoptera; C. dsRNA Reoviridae and Bir- naviridae, infecting mainly Diptera, Hymenoptera and Acarina, and plant viruses also multiplying in Hemiptera; D. Amb.-ssRNA Bunyaviridae and Tenuivirus, that multiply in Diptera and Hemiptera (animal viruses) and in Thysanoptera and Hemiptera (plant vi- ruses); E. -ssRNA Rhabdoviridae, multiplying in Diptera and Acarina (vertebrate vi- ruses), and mainly in Hemiptera (plant viruses); F.
    [Show full text]
  • Ibairwcanjauseum PUBLISHED by the AMERICAN MUSEUM of NATURAL HISTORY CENTRAL PARK WEST at 79TH STREET, NEW YORK 24, N.Y
    AoxfitatesibAirwcanJAuseum PUBLISHED BY THE AMERICAN MUSEUM OF NATURAL HISTORY CENTRAL PARK WEST AT 79TH STREET, NEW YORK 24, N.Y. NUMBER 2203 DECEMBER I5, I964 A Review of the Genus Hypochilus and a Description of a New Species from Colorado (Araneae, Hypochilidae) BY W. J. GERTSCH' The key position ofthe primitive spiders ofthe family Hypochilidae was noted by me in a revisional study ofthe world fauna (Gertsch, 1958). The hypochilids still retain features shared during Carboniferous times with primitive forebears and that are now found in no other true spiders. The disjunct distributions of the four known recent genera (with centers in North America, China, Tasmania, and southern Chile) reflect the early wide range and present near extinction ofthese relict types. The North American genus Hypochilus is reappraised and enlarged to four species in the present paper. In 1958 this genus was known from two principal areas: the southern Appalachian Mountains, with the species thorelli, and the central Sierra Nevada Mountains of California, with the species petrunkevitchi. The evident need for more adequate collections and fuller distributional information has prompted much recent interest in the group. The surprising discovery of a third species, named gertschi by Hoffman (1963), from Virginia and West Virginia was a reward ofvigi- lant collecting in the eastern mountains. Many new collections have been made during recent years in California, and these indicate a much broader range for the far western species than was anticipated. Finally, 'Curator, Department of Entomology, the American Museum of Natural History. 2 AMERICAN MUSEUM NOVITATES NO. 2203 an exciting event has been the discovery of a distinctive new species, bon- neti, in the deep canyons of southern Colorado.
    [Show full text]
  • Virus World As an Evolutionary Network of Viruses and Capsidless Selfish Elements
    Virus World as an Evolutionary Network of Viruses and Capsidless Selfish Elements Koonin, E. V., & Dolja, V. V. (2014). Virus World as an Evolutionary Network of Viruses and Capsidless Selfish Elements. Microbiology and Molecular Biology Reviews, 78(2), 278-303. doi:10.1128/MMBR.00049-13 10.1128/MMBR.00049-13 American Society for Microbiology Version of Record http://cdss.library.oregonstate.edu/sa-termsofuse Virus World as an Evolutionary Network of Viruses and Capsidless Selfish Elements Eugene V. Koonin,a Valerian V. Doljab National Center for Biotechnology Information, National Library of Medicine, Bethesda, Maryland, USAa; Department of Botany and Plant Pathology and Center for Genome Research and Biocomputing, Oregon State University, Corvallis, Oregon, USAb Downloaded from SUMMARY ..................................................................................................................................................278 INTRODUCTION ............................................................................................................................................278 PREVALENCE OF REPLICATION SYSTEM COMPONENTS COMPARED TO CAPSID PROTEINS AMONG VIRUS HALLMARK GENES.......................279 CLASSIFICATION OF VIRUSES BY REPLICATION-EXPRESSION STRATEGY: TYPICAL VIRUSES AND CAPSIDLESS FORMS ................................279 EVOLUTIONARY RELATIONSHIPS BETWEEN VIRUSES AND CAPSIDLESS VIRUS-LIKE GENETIC ELEMENTS ..............................................280 Capsidless Derivatives of Positive-Strand RNA Viruses....................................................................................................280
    [Show full text]
  • THEODOSIUS DOBZHANSKY January 25, 1900-December 18, 1975
    NATIONAL ACADEMY OF SCIENCES T H E O D O S I U S D O B ZHANSKY 1900—1975 A Biographical Memoir by F R A N C I S C O J . A Y A L A Any opinions expressed in this memoir are those of the author(s) and do not necessarily reflect the views of the National Academy of Sciences. Biographical Memoir COPYRIGHT 1985 NATIONAL ACADEMY OF SCIENCES WASHINGTON D.C. THEODOSIUS DOBZHANSKY January 25, 1900-December 18, 1975 BY FRANCISCO J. AYALA HEODOSIUS DOBZHANSKY was born on January 25, 1900 Tin Nemirov, a small town 200 kilometers southeast of Kiev in the Ukraine. He was the only child of Sophia Voinarsky and Grigory Dobrzhansky (precise transliteration of the Russian family name includes the letter "r"), a teacher of high school mathematics. In 1910 the family moved to the outskirts of Kiev, where Dobzhansky lived through the tumultuous years of World War I and the Bolshevik revolu- tion. These were years when the family was at times beset by various privations, including hunger. In his unpublished autobiographical Reminiscences for the Oral History Project of Columbia University, Dobzhansky states that his decision to become a biologist was made around 1912. Through his early high school (Gymnasium) years, Dobzhansky became an avid butterfly collector. A schoolteacher gave him access to a microscope that Dob- zhansky used, particularly during the long winter months. In the winter of 1915—1916, he met Victor Luchnik, a twenty- five-year-old college dropout, who was a dedicated entomol- ogist specializing in Coccinellidae beetles.
    [Show full text]