DOCSLIB.ORG

The P38mapk-MK2-HSP27 Axis Regulates the Mrna Stability of The

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
The P38mapk-MK2-HSP27 Axis Regulates the Mrna Stability of The Washington University in St. Louis Washington University Open Scholarship Arts & Sciences Electronic Theses and Dissertations Arts & Sciences Summer 8-15-2016 The p38MAPK-MK2-HSP27 axis regulates the mRNA stability of the pro-tumorigenic senescence-associated secretory phenotype Hayley Reynolds Moore Washington University in St. Louis Follow this and additional works at: https://openscholarship.wustl.edu/art_sci_etds Recommended Citation Moore, Hayley Reynolds, "The p38MAPK-MK2-HSP27 axis regulates the mRNA stability of the pro-tumorigenic senescence- associated secretory phenotype" (2016). Arts & Sciences Electronic Theses and Dissertations. 873. https://openscholarship.wustl.edu/art_sci_etds/873 This Dissertation is brought to you for free and open access by the Arts & Sciences at Washington University Open Scholarship. It has been accepted for inclusion in Arts & Sciences Electronic Theses and Dissertations by an authorized administrator of Washington University Open Scholarship. For more information, please contact [email protected]. WASHINGTON UNIVERSITY IN ST. LOUIS Division of Biology and Biomedical Sciences Molecular Cell Biology Dissertation Examination Committee: Sheila A. Stewart, Chairperson Peter Burgers Nicholas Davidson Sergej Djuranovic Joshua Rubin Zhongsheng You The p38MAPK-MK2-HSP27 axis regulates the mRNA stability of the pro-tumorigenic senescence-associated secretory phenotype by Hayley R. Moore A dissertation presented to the Graduate School of Arts & Sciences of Washington University in partial fulfillment of the requirements for the degree of Doctor of Philosophy August 2016 St. Louis, Missouri Table of Contents List of figures ................................................................................................................................. v Acknowledgements ...................................................................................................................... vii Abstract ......................................................................................................................................... ix Chapter 1: Background and Significance, Senescence .............................. 1 1.1 Overview and significance ..................................................................................... 2 1.2 Mechanisms governing senescence ....................................................................... 4 1.3 The senescence-associated secretory phenotype ................................................... 5 1.4 Transcriptional regulation of the SASP ................................................................. 7 1.5 Post-transcriptional regulation of SASP mRNAs.................................................. 9 1.5.1 AUF1 and AU-rich-element-mediated mRNA degradation ............................ 10 1.5.2 The p38MAPK-MK2 mRNA degradation pathway ........................................ 11 1.6 Summary .............................................................................................................. 13 References ........................................................................................................................ 17 Chapter 2: The p38MAPK-MK2-HSP27 axis regulates the mRNA stability of the senescence-associated secretory phenotype .......................... 23 Abstract ............................................................................................................................ 24 Introduction ...................................................................................................................... 24 Materials and Methods ..................................................................................................... 28 Results .............................................................................................................................. 33 HSP27 destabilizes SASP factor mRNA in pre-senescent cells ........................... 33 p38MAPK and MK2 regulate mRNA stability in senescent cells ........................ 35 The p38MAPK-MK2-AUF1 axis regulates mRNA stability in senescent cells through HSP27 phosphorylation ...................................................................... 37 The p38MAPK-MK2-HSP27 axis promotes stromal-supported tumor cell growth .............................................................................................. 40 Discussion ........................................................................................................................ 41 Acknowledgements .......................................................................................................... 46 References ........................................................................................................................ 54 Chapter 3: Conclusions and Future Directions, Senescence ................ 58 3.1 Summary .............................................................................................................. 59 3.2 The p38MAPK-MK2-HSP27-AUF1 axis regulates post-transcriptional stabilization of SASP factor mRNAs in senescence ........................................ 60 ii 3.3 Inhibiting the p38MAPK-MK2-HSP27 pathway abrogates the growth promotion of epithelial cells by senescent fibroblasts ................... 63 3.4 Conclusions .......................................................................................................... 65 References ........................................................................................................................ 67 Chapter 4: Background and Significance, DNA metabolism ............... 69 4.1 Overview and significance .................................................................................. 70 4.2 Genomic instability as a driver of disease ........................................................... 70 4.2.1 DNA replication fidelity .................................................................................. 71 4.2.2 DNA repair and replication fork progression .................................................. 72 4.2.3 Telomere maintenance ..................................................................................... 73 4.3 Dna2 functions to ensure genomic stability ......................................................... 75 4.3.1 Dna2’s function in lagging-strand DNA replication ........................................ 77 4.3.2 Dna2 participates in homologous recombination ............................................ 78 4.3.3 Dna2 protects telomere integrity ...................................................................... 78 4.4 Summary .............................................................................................................. 80 References ........................................................................................................................ 84 Chapter 5: An Okazaki fragment processing-independent role for human Dna2 during DNA replication ............................... 90 Abstract ............................................................................................................................ 91 Introduction ...................................................................................................................... 92 Materials and Methods ..................................................................................................... 94 Results ............................................................................................................................ 101 hDna2 contributes to genomic stability ............................................................. 101 hDna2’s nuclease and helicase activities are essential ..................................... 102 hDna2 interacts with the replisome protein And-1 in a replication dependent manner ................................................................. 104 hDna2 depletion leads to replication checkpoint activation ............................. 105 Defects in Okazaki fragment processing do not alter replication fork progression ........................................................................... 107 hDna2 depletion does not lead to detectable defects in maturation of newly synthesized DNA ........................................................ 108 Discussion ...................................................................................................................... 110 Acknowledgements ........................................................................................................ 114 References ...................................................................................................................... 124 iii Chapter 6: Conclusions and Future Directions, DNA metabolism ..130 6.1 Summary ............................................................................................................ 131 6.2 Dna2 has non-Okazaki fragment processing roles in DNA replication ............ 131 6.3 Dna2 is required for replication fork restart ...................................................... 133 6.4 Dna2 knockout induces a stringent cell cycle arrest and abnormal metaphase chromosomes ......................................................... 135 6.5 Conclusions ....................................................................................................... 137 Materials and methods ................................................................................................... 138 References .....................................................................................................................
Load more

Recommended publications
  • JOHN J. O'connor Fashionable Tailor
    ^ GNATIAN CONSIDER THE EARNING POWER OF YOUR TRAINING who are graduating or leaving school to enter the Qll business world would do well to earnestly consider the Y•"" I big advantage of a Heald training. Consider what it means to you now—what it will mean to you ten years from now to stand where former Heald graduates now stand—Bank Presidents, Heads of large Corporations, Con­ fidential Accountants, Secretaries, Business Executives in every line of Commercial enterprise. Heald's Courses cover every essential and modern study that make for the best business minds in the country. You need not hesitate if you are behind in some study—you can make it up and receive every help at Heald's. Tour progress is sure and certain—you are not held back by the slower student—no waiting for the other fellow at Heald's. Enroll now. Call or phone Prospect 1540. Heald's Business College VAN NESS AVENUE AND POST ST. San Francisco, Cal. TELEPHONE PROSPECT 1540 But Chips of Glass WO chips of glass. T Jt,'fOle I never saw tlic stars, Nor butterflies with oainted hars, Nor blades of ptsft. The yellow btM 1 never saw. nor lillle birds. But only heard their friendly words From blurred, green trees. The world did seem Vi'.gue. dull—I knew not whv; 1 only knew all earth and sky Dim as a dream. And then these hits of glass! Oh. myriad life! Oh, wonder sight | Oh, jeweled world! Oh, star- hung night! My soul go,*s dancing with de­ light! THANK GOD for chips of glass! Compliments of Dr.
    [Show full text]
  • A Victorian Curate: a Study of the Life and Career of the Rev. Dr John Hunt
    D A Victorian Curate A Study of the Life and Career of the Rev. Dr John Hunt DAVID YEANDLE AVID The Rev. Dr John Hunt (1827-1907) was not a typical clergyman in the Victorian Church of England. He was Sco� sh, of lowly birth, and lacking both social Y ICTORIAN URATE EANDLE A V C connec� ons and private means. He was also a wi� y and fl uent intellectual, whose publica� ons stood alongside the most eminent of his peers during a period when theology was being redefi ned in the light of Darwin’s Origin of Species and other radical scien� fi c advances. Hunt a� racted notoriety and confl ict as well as admira� on and respect: he was A V the subject of ar� cles in Punch and in the wider press concerning his clandes� ne dissec� on of a foetus in the crypt of a City church, while his Essay on Pantheism was proscribed by the Roman Catholic Church. He had many skirmishes with incumbents, both evangelical and catholic, and was dismissed from several of his curacies. ICTORIAN This book analyses his career in London and St Ives (Cambs.) through the lens of his autobiographical narra� ve, Clergymen Made Scarce (1867). David Yeandle has examined a li� le-known copy of the text that includes manuscript annota� ons by Eliza Hunt, the wife of the author, which off er unique insight into the many C anonymous and pseudonymous references in the text. URATE A Victorian Curate: A Study of the Life and Career of the Rev.
    [Show full text]
  • ADAPTATION of FORESTS and PEOPLE to CLIMATE Change – a Global Assessment Report
    International Union of Forest Research Organizations Union Internationale des Instituts de Recherches Forestières Internationaler Verband Forstlicher Forschungsanstalten Unión Internacional de Organizaciones de Investigación Forestal IUFRO World Series Vol. 22 ADAPTATION OF FORESTS AND PEOPLE TO CLIMATE CHANGE – A Global Assessment Report Prepared by the Global Forest Expert Panel on Adaptation of Forests to Climate Change Editors: Risto Seppälä, Panel Chair Alexander Buck, GFEP Coordinator Pia Katila, Content Editor This publication has received funding from the Ministry for Foreign Affairs of Finland, the Swedish International Development Cooperation Agency, the United Kingdom´s Department for International Development, the German Federal Ministry for Economic Cooperation and Development, the Swiss Agency for Development and Cooperation, and the United States Forest Service. The views expressed within this publication do not necessarily reflect official policy of the governments represented by these institutions. Publisher: International Union of Forest Research Organizations (IUFRO) Recommended catalogue entry: Risto Seppälä, Alexander Buck and Pia Katila. (eds.). 2009. Adaptation of Forests and People to Climate Change. A Global Assessment Report. IUFRO World Series Volume 22. Helsinki. 224 p. ISBN 978-3-901347-80-1 ISSN 1016-3263 Published by: International Union of Forest Research Organizations (IUFRO) Available from: IUFRO Headquarters Secretariat c/o Mariabrunn (BFW) Hauptstrasse 7 1140 Vienna Austria Tel: + 43-1-8770151 Fax: + 43-1-8770151-50 E-mail: [email protected] Web site: www.iufro.org/ Cover photographs: Matti Nummelin, John Parrotta and Erkki Oksanen Printed in Finland by Esa-Print Oy, Tampere, 2009 Preface his book is the first product of the Collabora- written so that they can be read independently from Ttive Partnership on Forests’ Global Forest Expert each other.
    [Show full text]
  • Spectacular Fire Ruins Egan Ford Building Here
    770,000 dimes, 308,000 quarters. and one penny (Excedrin headache No. 150,000 for manager of bank at Ovid) By LOWELL G. RINKER I never would have accepted it had I known what call that the money was in Ovid waiting to be un­ determination, It became the duty of the country comfortable in there for a while until the dust Editor it was all about. And I would not wish it on any­ loaded and stored. ToTabor'ssurprise,hefound treasurer in the county where the money was died down. We used a square quarter-inch body." a. heavy equipment truck parked at the side of stored to come in and make an inventory. screen to screen the dust out." OVID—One of the great fascinating untold The story he tells is fascinating, even if it the bank. On it was a single wooden box about "It was just like opening a lock box, actual­ A machine was used to count the coins, but stories of the year 1968 can now he told. It in­ Isn't complete. For understandable reasons, six by 10 feet in size, filled with bags of silver ly," Tabor pointed out. "She (Mrs Velma Beau- even then it took a long time. Three minutes volved more than a million dimes and quarters, Tabor is not disclosing the names of the people coins! fore, Clinton County treasurer) would make an were necessary to count $1,000 in quarters, and plus one penny and probably a hottle of Excedrin. involved nor even where they're from.
    [Show full text]
  • Annual Report 2005
    NATIONAL GALLERY BOARD OF TRUSTEES (as of 30 September 2005) Victoria P. Sant John C. Fontaine Chairman Chair Earl A. Powell III Frederick W. Beinecke Robert F. Erburu Heidi L. Berry John C. Fontaine W. Russell G. Byers, Jr. Sharon P. Rockefeller Melvin S. Cohen John Wilmerding Edwin L. Cox Robert W. Duemling James T. Dyke Victoria P. Sant Barney A. Ebsworth Chairman Mark D. Ein John W. Snow Gregory W. Fazakerley Secretary of the Treasury Doris Fisher Robert F. Erburu Victoria P. Sant Robert F. Erburu Aaron I. Fleischman Chairman President John C. Fontaine Juliet C. Folger Sharon P. Rockefeller John Freidenrich John Wilmerding Marina K. French Morton Funger Lenore Greenberg Robert F. Erburu Rose Ellen Meyerhoff Greene Chairman Richard C. Hedreen John W. Snow Eric H. Holder, Jr. Secretary of the Treasury Victoria P. Sant Robert J. Hurst Alberto Ibarguen John C. Fontaine Betsy K. Karel Sharon P. Rockefeller Linda H. Kaufman John Wilmerding James V. Kimsey Mark J. Kington Robert L. Kirk Ruth Carter Stevenson Leonard A. Lauder Alexander M. Laughlin Alexander M. Laughlin Robert H. Smith LaSalle D. Leffall Julian Ganz, Jr. Joyce Menschel David O. Maxwell Harvey S. Shipley Miller Diane A. Nixon John Wilmerding John G. Roberts, Jr. John G. Pappajohn Chief Justice of the Victoria P. Sant United States President Sally Engelhard Pingree Earl A. Powell III Diana Prince Director Mitchell P. Rales Alan Shestack Catherine B. Reynolds Deputy Director David M. Rubenstein Elizabeth Cropper RogerW. Sant Dean, Center for Advanced Study in the Visual Arts B. Francis Saul II Darrell R. Willson Thomas A.
    [Show full text]
  • Cambridge University Press 978-1-107-15445-2 — Mercury Edited by Sean C
    Cambridge University Press 978-1-107-15445-2 — Mercury Edited by Sean C. Solomon , Larry R. Nittler , Brian J. Anderson Index More Information INDEX 253 Mathilde, 196 BepiColombo, 46, 109, 134, 136, 138, 279, 314, 315, 366, 403, 463, 2P/Encke, 392 487, 488, 535, 544, 546, 547, 548–562, 563, 564, 565 4 Vesta, 195, 196, 350 BELA. See BepiColombo: BepiColombo Laser Altimeter 433 Eros, 195, 196, 339 BepiColombo Laser Altimeter, 554, 557, 558 gravity assists, 555 activation energy, 409, 412 gyroscope, 556 adiabat, 38 HGA. See BepiColombo: high-gain antenna adiabatic decompression melting, 38, 60, 168, 186 high-gain antenna, 556, 560 adiabatic gradient, 96 ISA. See BepiColombo: Italian Spring Accelerometer admittance, 64, 65, 74, 271 Italian Spring Accelerometer, 549, 554, 557, 558 aerodynamic fractionation, 507, 509 Magnetospheric Orbiter Sunshield and Interface, 552, 553, 555, 560 Airy isostasy, 64 MDM. See BepiColombo: Mercury Dust Monitor Al. See aluminum Mercury Dust Monitor, 554, 560–561 Al exosphere. See aluminum exosphere Mercury flybys, 555 albedo, 192, 198 Mercury Gamma-ray and Neutron Spectrometer, 554, 558 compared with other bodies, 196 Mercury Imaging X-ray Spectrometer, 558 Alfvén Mach number, 430, 433, 442, 463 Mercury Magnetospheric Orbiter, 552, 553, 554, 555, 556, 557, aluminum, 36, 38, 147, 177, 178–184, 185, 186, 209, 559–561 210 Mercury Orbiter Radio Science Experiment, 554, 556–558 aluminum exosphere, 371, 399–400, 403, 423–424 Mercury Planetary Orbiter, 366, 549, 550, 551, 552, 553, 554, 555, ground-based observations, 423 556–559, 560, 562 andesite, 179, 182, 183 Mercury Plasma Particle Experiment, 554, 561 Andrade creep function, 100 Mercury Sodium Atmospheric Spectral Imager, 554, 561 Andrade rheological model, 100 Mercury Thermal Infrared Spectrometer, 366, 554, 557–558 anorthosite, 30, 210 Mercury Transfer Module, 552, 553, 555, 561–562 anticline, 70, 251 MERTIS.
    [Show full text]
  • Icy Discoveries on Our Innermost Planet
    Icy Discoveries on Our Innermost Planet Dr Nancy Chabot Dr Carolyn Ernst Ariel Deutsch, PhD Candidate ICY DISCOVERIES ON OUR INNERMOST PLANET The location of water in our solar system may hold the key to understanding how the planets evolved, and indicate other potential places to find life away from Earth. Dr Nancy Chabot and Dr Carolyn Ernst of Johns Hopkins University Applied Physics Laboratory, and Ariel Deutsch at Brown University, use data from NASA’s MESSENGER mission to understand how much ice exists on Mercury and how it may have arrived there. Mercury’s south polar region, with Arecibo radar data in pink indicating the locations of ice, and a colourised map of illumination conditions, showing regions of permanent shadow in black The Search for Water of ice on Mercury using data collected that locations at the planet’s cratered from NASA’s MErcury Surface, Space poles are permanently in shade. In The question of whether we are alone ENvironment, GEochemistry, and this shade, where direct sunlight never in the Universe has fuelled humanity’s Ranging (MESSENGER) spacecraft. reaches, the temperatures can be very curiosity with space since we first looked low, reaching −160°C where ice can be up to the stars. From our perspective, NASA’s MESSENGER Mission stable. Earth is the perfect habitable planet – it has a rocky surface with an atmosphere The MESSENGER mission was the first to The MESSENGER spacecraft was and liquid water to support life. By visit Mercury since the Mariner 10 flybys equipped with a narrow-angle camera looking for evidence of water on in the mid-1970s, and the first mission and a wide-angle filtered camera, and other planets, scientists can start to ever to orbit the planet.
    [Show full text]
  • How Thick Are Mercury's Polar Water Ice Deposits?
    Mon. Not. R. Astron. Soc. 000, 000–000 (0000) Printed 17 November 2016 (MN LATEX style file v2.2) How thick are Mercury’s polar water ice deposits? Vincent R. Eke1, David J. Lawrence2, Lu´ıs F. A. Teodoro3 1Institute for Computational Cosmology, Department of Physics, Durham University, Science Laboratories, South Road, Durham DH1 3LE, U.K. 2Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, U.S.A. 3BAER, Planetary Systems Branch, Space Science and Astrobiology Division, MS: 245-3, NASA Ames Research Center, Moffett Field, CA 94035-1000, U.S.A. 17 November 2016 ABSTRACT An estimate is made of the thickness of the radar-bright deposits in craters near to Mer- cury’s north pole. To construct an objective set of craters for this measurement, an automated crater finding algorithm is developed and applied to a digital elevation model based on data from the Mercury Laser Altimeter onboard the MESSENGER spacecraft. This produces a catalogue of 663 craters with diameters exceeding 4 km, northwards of latitude +55◦. A sub- set of 12 larger, well-sampled and fresh polar craters are selected to search for correlations between topography and radar same-sense backscatter cross-section. It is found that the typ- ical excess height associated with the radar-bright regions within these fresh polar craters is (50 ± 35) m. This puts an approximate upper limit on the total polar water ice deposits on Mercury of ∼ 3 × 1015 kg. 1 INTRODUCTION was that there was multiple scattering occurring within a low-loss medium such as water ice (Hapke 1990; Hagfors et al.
    [Show full text]
  • The Stetson Collegiate, Vol. 03, No. 02, March, 1893
    University of Central Florida STARS Stetson Collegiate Newspapers and Weeklies of Central Florida 3-1-1893 The Stetson Collegiate, Vol. 03, No. 02, March, 1893 Stetson University Find similar works at: https://stars.library.ucf.edu/cfm-stetsoncollegiate University of Central Florida Libraries http://library.ucf.edu This Newspaper is brought to you for free and open access by the Newspapers and Weeklies of Central Florida at STARS. It has been accepted for inclusion in Stetson Collegiate by an authorized administrator of STARS. For more information, please contact [email protected]. STARS Citation Stetson University, "The Stetson Collegiate, Vol. 03, No. 02, March, 1893" (1893). Stetson Collegiate. 10. https://stars.library.ucf.edu/cfm-stetsoncollegiate/10 YOL. III. MARCH, 1896 NO. 2. '•-:>i^-K>l^;^^gfe^>^i,£r-.-'^5<-.- THE STETSON COLLEGIATE PUBLISHED MONTHLY ... BY THE , . STUDENTS OF ... JOHN B. STETSON -«—^UNIVERSITY iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii.iin TMBLE OF=i CONTENTS: EDITORIALS— i MISCELLANEOUS—Continued. Notes, I § Rhetorical Exercises, 7 The American Citizen (poetry), . i ^ Danger in Singing, 7 School Training for Citizenship, . 1-2 E Probing a Volcano, 7 The Spoils System and Civil 1 Exchange Items, 7-8 Service Reform 2-3 = Music Recital, 8 Lord Tennyson, 3 | LOCAL AND PERSONAL, .... 8-9 MISCELLANEOUS- | ADVERTISEMENTS— Palestine, , . 4-5 1 First, second, third and fourth pages of C. T. Sampson, 6 f cover, and pages 10, 11 and 12. THE STETSOJV COLLEGIATE. @IPANY HALTL AT THE CHEAPEST AJVD BEST PLACE IJV TO WJV TO BUY SHOES AJ^D HARJVESS. G. N. MESSIMER. Corell &: Stewart's Sale Stable. HORSES AND MULES FOR SALE PASSENGERS AND BAGGAGE TRANSFERRED TO ANY PART OF THE CITY.
    [Show full text]
  • Annotated Bibliography of Climate and Forest Diseases of Western North America
    Climate and Forest Disease | Ecosystem Effects | Climate Change | PSW Research Station Page 1 of 156 Pacific Southwest Research Station Annotated Bibliography of Climate and Forest Diseases of Western North America Hennon, P.E. 1990. Etiologies of forest declines in western North America. In: Proceedings of Society of American Foresters: Are forests the answer? Washington, D.C.; 1990 July 29-August 1. Bethesda, MD: Society of American Foresters: 154–159. Parker, A.K. 1951. Pole blight recorded on the British Columbia coast. Forest Pathological Notes Number 4. Laboratory of Forest Pathology, Victoria, B.C.: 5 p. Leaphart, C.D.; Stage, A.R. 1971. Climate: a factor in the origin of the pole blight disease of Pinus monticola Dougl.. Ecology. 52: 229–239. Abstract: Measurements of cores or disc samples representing slightly more than 76,000 annual rings from 336 western white pine tree were compiled to obtain a set of deviations from normal growth of healthy trees that would express the response of these trees to variation in the environment during the last 280 years. Their growth was demonstrated to be a function of temperature and available moisture for the period of climatic record from 1912 to 1958. Extrapolating the relation of growth to weather to the long tree ring record of western white pine, we find that the period 1916—40 represents the most adverse growth conditions with regard to intensity and duration in the last 280 years. This drought, superimposed on sites having severe moisture—stress characteristics, triggered the chain of events which ultimately resulted in pole blight. If the unfavorable conditions for growth during 1916—40 do not represent a shift to a new climatic mean and if western white pine is regenerated only on sites with low moisture—stress characteristics, the probability is high that pole blight will not reoccur for many centuries in stands regenerated from this date on.
    [Show full text]
  • Constraining the Depth of Polar Ice Deposits and Evolution of Cold Traps on Mercury with Small Craters in Permanently Shadowed Regions
    Lunar and Planetary Science XLVIII (2017) 1634.pdf CONSTRAINING THE DEPTH OF POLAR ICE DEPOSITS AND EVOLUTION OF COLD TRAPS ON MERCURY WITH SMALL CRATERS IN PERMANENTLY SHADOWED REGIONS. Ariel N. Deutsch1, James W. Head1, Gregory A. Neumann2, Nancy L. Chabot3, 1Department of Earth, Environmental and Planetary Sciences, Brown University, Providence, RI 02912, USA ([email protected]), 2NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA, 3The Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA. Introduction: Earth-based radar observations re- tracks. If these small craters pre-dated ice emplacement, vealed highly reflective deposits at the poles of Mercury then the infilled material can constrain the thickness of [e.g., 1], which collocate with permanently shadowed the ice within them. We suggest that the small craters regions (PSRs) detected from both imagery and altime- were formed before the ice was delivered to these re- try by the MErcury Surface, Space ENvironment, GEo- gions because albedo variations are not correlated with chemistry, and Ranging (MESSENGER) spacecraft the small craters, and there is no evidence for ejecta, [e.g., 2]. MESSENGER also measured higher hydrogen although this could be a resolution effect of the images. concentrations at the north polar region, consistent with Depth-to-diameter ratios. Measurements were taken models for these deposits to be composed primarily of of the diameters of any craters that are visible in the water ice [3]. permanently shadowed, radar-bright deposits. The depth Enigmatic to the characterization of ice deposits on of each small crater was then derived using the defined Mercury is the thickness of these radar-bright features.
    [Show full text]
  • (Quercus Robur L.) and the Microbial Community of Its Phyllosphere Boris Jakuschkin
    Genetic architecture of the interactions between English oak (Quercus robur L.) and the microbial community of its phyllosphere Boris Jakuschkin To cite this version: Boris Jakuschkin. Genetic architecture of the interactions between English oak (Quercus robur L.) and the microbial community of its phyllosphere. Symbiosis. Université de Bordeaux, 2015. English. NNT : 2015BORD0170. tel-01665488 HAL Id: tel-01665488 https://tel.archives-ouvertes.fr/tel-01665488 Submitted on 16 Dec 2017 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. …….. …….. …….. é ….. ….. ….. ….. II Résumé De nombreux et divers micro-organismes vivent dans les tissus interne et externe des feuilles des plantes, la phyllosphère. Ils influencent de nombreux traits, les interactions bio- tiques, le flux d’énergie, la tolérance au stress de leur hôte et en fin de compte la valeur sélec- tive de leurs hôtes. Il a été montré que plusieurs traits quantitatifs de plantes structurent la communauté microbienne de la phyllosphère. Ainsi des Loci de ces traits quantitatifs (Quantitative Trait Loci QTL) liés à la structure de cette communauté étaient attendus. L’objectif principal de ce travail était de rechercher des régions génomiques chez le chêne (Quercus robur L.), dont l’effet se prolonge jusqu’au niveau de la communauté, influencant ainsi le microbiote de la phyllosphère.
    [Show full text]