Virus classification Structure Replication Youhua xie(谢幼华) MOH&MOE Key Lab of Medical Molecular Virology Shanghai Medical College, Fudan University 复旦大学上海医学院 分子病毒学教育部/卫生部重点实验室 yhxie@fudan.edu.cn
Virus Classification, Structure & Replication Youhua Xie Youhua Xie (谢幼华 ) MOH&MOE Key Lab of Medical Molecular Virology Sh h i M di l C ll F d U i it Shang h ai M edical C ollege, F u dan U niversit y 复旦大学上海医学院 分子病毒学教育部 /卫生部重点实验室 yhxie@fudan.edu.cn
The nature of viruses Viruses are small infectious agents(diameter 20-300 nm) @ Parvovirus picornavirus Papovavirus Adenovirus Influenza virus Ryan K), Ray Co Herpesvirus Infectious agents smaller than viruses s, prons Giant virus: Mimivirus( 400 nm, genome size 1.2 Mb), Pandoravirus (1 um, genome size 1.9-2. 5 Mb)
The Nature of Viruses Viruses are small infectious agents (diameter 20 ‐300 nm) Infectious agents smaller than viruses: viroids, prions Gi t i an v rus: Mi i i m virus (400 nm, genome size 1.2 Mb), Pandoravirus (1 um, genome size 1.9-2.5 Mb)
The nature of viruses Viruses contain one kind of nucleic acid (dNa or RNa genome) inside a protein shell (capsid), which may be surrounded by a lipid bilayer membrane(envelope). The resulting complete virus particle s called a virion Membrane Matrix prote Nucleocapsid Capsid (icosahedral) ource: Ryan K), Ray CG: Sherris Medical Microbiology, Sth Edition: Copyright o The McGraw-Hill Companies, Inc. All rights reserved
The Nature of Viruses ¾ Viruses Viruses contain contain one kind of nucleic nucleic acid (DNA or RNA genome) inside a protein shell (capsid), which may be surrounded by a lipid bila yer membrane (envelo p e). The resultin g com plete virus particle is called a virion
All Cellular Lives survive in a sea of viruses Viruses are major players in the ecosystem, infecting every cellular life Animals: animal viruses Plants: plant viruses Archaea: archae viruses Fungi: mycoviruses(真菌病毒) Bacteria: bacteriophages(噬菌体) Viruses constitute a substantial amount of biomass on the earth (eg. there are 1030 bacteriophage particles alone in waters on the earth) 1 phage weighs about 1 femtogram(10-15 gram) 1030 phages weigh about =10-15 x 1030= 1015 gram 10 kilogram 109 tons
All Cellular Lives Survive in a Sea of Viruses ¾ Viruses are major players in the ecosystem infecting every Viruses are major players in the ecosystem, infecting every cellular life z Animals: animal viruses z Plants: plant viruses z Archaea: archae viruses z Fungi: mycoviruses （真菌病毒 ） z Bacteria: bacteriophages (噬菌体 ） z …… ¾ Viruses constitute a substantial amount of biomass on the earth ( th 1030 (eg. there are 10 b t i h ti l l i t th 30 bac teriop hage parti cles alone in wa ters on the earth) 1 phage weighs about 1 femtogram (10-15 1 phage weighs about 1 femtogram (10 gram ) 1030 phages weigh about = 10-15 x 1030 = 1015 gram = 1012 kilogram = 109 tons
Viruses are obligate cellular Parasites Viruses multiplicate(replicate) inside host cells Viruses utilize cellular machineries for replication synthesis of proteins synthesis of membranes synthesis of amino acid, carbohydrates and lipids generatation of energy
Viruses Are Obligate Cellular Parasites ¾ Viruses multiplicate (replicate) inside host cells ¾ Viruses utilize cell l u ar machi i ner es for repli ti ca on z synthesis of proteins z synthesis of membranes z synthesis of amino acid, carbohydrates and lipids z generatation of energy
Selected Milestones in Virology Discovery Year Scientist Nobel prize Smallpox vaccine 1798 Edward Jenner Rabies vaccine 1885 Louis Pasteur Viruses are filtrable Tobacco mosaic virus 1892 Dimitrii Ivanovski 1898 Martinus beijerinck Rous sarcoma virus 1911 Peyton rous Bacteriophages and the 1915 Frederick Twort plaque assay 1917 Felix d Herelle Crystallization of tobacco 1935 Wendell Stanley and John Northrup 1946 mosaic virus Bacteriophage genes are 1952 Alfred Hershey and Martha Chase 1969 DNA Discovery of interferons 1957 Alick Isaacs and Jean Lindenmann
Selected Milestones in Virology Discovery Year Scientist Nobel prize Smallpox vaccine 1798 Edward Jenner Rabies vaccine Rabies vaccine 1885 Louis Pasteur Louis Pasteur Viruses are filtrable Tobacco mosaic virus 1892 1898 Dimitrii Ivanovski Martinus Beijerinck Martinus Beijerinck Rous Sarcoma virus 1911 Peyton Rous 1966 Bacteriophages and the 1915 Frederick Twort plaque assay 1917 Felix d’Herelle Crystallization of tobacco mosaic virus 1935 Wendell Stanley and John Northrup 1946 mosaic virus Bacteriophage genes are DNA 1952 Alfred Hershey and Martha Chase 1969 Di f i f Discovery o f inter ferons 1957 Ali kc k I d J Li d Isaacs an d Jean Li n denmann
Selected Milestones in Virology Discovery Year Scientists Nobel prize Polio vaccines 1955 Jonas Salk 1960 Albert Sabin Reverse transcriptase of 1971 Howard Temin and David Baltimore 1975 retroviruses Virus vectors and gentic 1970s Paul Berg 1980 engineering Cellular oncogene in a 1976 Michael Bishop and Harold Varmus 1989 retrovirus RNA Splicing in adenovirus 1977 Phillip sharp and richard roberts 1993 Discovery of Human 1983 Barre-Sinoussi F& montagnier L 08 Immunodeficiency Virus HBV vaccine(recombinant) 1986 HPV vaccine(recombinant) 2006
Selected Milestones in Virology Discovery scove r y Year Scientists ie n tists Nobel prize Polio vaccines 1955 1960 Jonas Salk Albert Sabin Albert Sabin Reverse transcriptase of retroviruses 1971 Howard Temin and David Baltimore 1975 Virus vectors and gentic engineering 1970s Paul Berg 1980 Cellular onco gene in a 1976 Michael Bisho p and Harold Varmus 1989 retrovirus RNA splicing in adenovirus 1977 Phillip Sharp and Richard Roberts 1993 Di f H scovery o f Human 1983 B é Si i F & M i L 2008 Immunodeficiency Virus 1983 Barr é -Sinoussi F. & Montagnier L. 2008 HBV vaccine (recombinant) 1986 HPV vaccine (recombinant) 2006
Virus classification http://www.ictvonline.org a virus species is a polythetic class of viruses that constitute a replicating lineage and occupy a particular ecological niche Apolythetic class is one whose members have several properties in common, although they do not necessarily all share a single common defining property. In other words, the members of a virus species are defined collectively by a consensus group of properties
Virus Classification http://www.ictvonline.org/ “a virus species is a polythetic class of viruses that constitute a replicating lineage and occupy a particular ecological niche”. A “polythetic class” is one whose members have several properti i l h h h d il ll ies in common, a l thoug h they do not necessarily all share a single common defining property. In other words, th b f i i d fi d ll ti l b the mem bers o f a virus spec ies are d efine d collective ly by a consensus group of properties
Common Properties for virus classification Virion morphology Nature of genome in virion Presence or absence of lipid membrane (envelope) Genome organization and replication Antigenic properties Biological properties
Common Properties for Virus Classification ¾ Virion morphology ¾ Nature of genome in virion Nature of genome in virion ¾ Presence or absence of lipid membrane (envelope) ¾ Genome organization and replication ¾ Antigenic properties ¾ Biological properties Biological properties
Current ICTV Virus classification The most recent report: Virus Taxonomy: IXth Report of the International Committee on Taxonomy of Viruses", 2012 目 Orders(- virale):7 科 Families( viridae):96 >亚科 Subfamilies( venae):22 属 Genera(irus):420 种 Species:2618
Current ICTV Virus Classification The most recent re p y ort: "Virus Taxonom y: IXth Re port of the International Committee on Taxonomy of Viruses", 2012 ¾ 目 Orders (-virale): 7 ¾ 科 Families ( Families ( -viridae viridae): 96 ¾ 亚科 Subfamilies (-virinae): 22 ¾ 属 Genera (-virus): 420 ¾ 种 Species: 2618 Species: 2618