上游充通大 SHANGHAI JIAO TONG UNIVERSITY 1896 1920 1987 2006 Virus:Growth,quantification,replication and diversity Lecture 9-1 Essentials of Virology CHAPTER 9 in BROCK BIOLOGY OF MICROORGANISMS Chen FengoNG School of Life Science and Biotechnology. Shanghai Jiao Tong University Email:cf2001@sjtu.edu.cn http://micro.sjtu.edu.cn
1896 1920 1987 2006 Lecture 9-1 Essentials of Virology Virus: Growth, quantification, replication and diversity Chen Feng School of Life Science and Biotechnology, Shanghai Jiao Tong University Email: cf2001@sjtu.edu.cn http://micro.sjtu.edu.cn CHAPTER 9 in BROCK BIOLOGY OF MICROORGANISMS
上浒充通大淫 SHANGHAI JIAO TONG UNIVERSITY What is a virus? One type of genetic elements Nucleic acid Replication independent of a cell's chromosome复制独立于细胞的染色体 Multiplication dependent on host cell's metabolism繁殖依赖于细胞的代谢 ·Have Extracellular state-virus particles有胞外 形式（病毒粒子） Chen Feng,Shanghai Jiao Tong University
Chen Feng, Shanghai Jiao Tong University What is a virus? One type of genetic elements • Nucleic acid Replication independent of a cell’s chromosome复制独立于细胞的染色体 • Multiplication dependent on host cell’s metabolism繁殖依赖于细胞的代谢 • Have Extracellular state-virus particles有胞外 形式(病毒粒子)
上游充通大学 SHANGHAI JIAO TONG UNIVERSITY Differences between virus and plasmid? Virus has extracellular state,plasmid does not Virus can cause cell lysis,plasmid does not Chen Feng,Shanghai Jiao Tong University
Chen Feng, Shanghai Jiao Tong University Differences between virus and plasmid? Virus has extracellular state, plasmid does not Virus can cause cell lysis, plasmid does not …………………
上游充通大 SHANGHAI JIAO TONG UNIVERSITY I.VIRUS AND VIRON 9.1 General Properties of Viruses 9.2 Nature of the virion Chen Feng,Shanghai Jiao Tong University
Chen Feng, Shanghai Jiao Tong University I. VIRUS AND VIRION 9.1 General Properties of Viruses 9.2 Nature of the virion
上浒充通大淫 SHANGHAI JIAO TONG UNIVERSITY 9.1 General properties of viruses Extracellular state胞外形式 Is a minute particle containing nucleic acid surrounded by protein(and occasionally,containing other macromolecular components) ·Virus particle/virion:metabolically inert毒粒：代谢隋性 ©Intracellular state胞内形式 Virus Replication occurs:New copies of virus genome are produced,and the virus coat components are synthesized. Infection the process when a virus genome is introduced into a host cell and reproduces感染 Chen Feng,Shanghai Jiao Tong University
Chen Feng, Shanghai Jiao Tong University 9.1 General properties of viruses Extracellular state胞外形式 • Is a minute particle containing nucleic acid surrounded by protein (and occasionally, containing other macromolecular components) • Virus particle/virion: metabolically inert毒粒:代谢隋性 Intracellular state胞内形式 • Virus Replication occurs: New copies of virus genome are produced, and the virus coat components are synthesized. • Infection : the process when a virus genome is introduced into a host cell and reproduces感染
9.1.1 Types of Viral Genomes The genomes of viruses:DNA or RNA,and some use both as their genomic material at different stages in their life cycle.However,only one type of nucleic acid is found in the virion of any particular type of virus.This can be single-stranded (ss),double-stranded (ds). 因组可以是DNA或RNA,可以是单链或双链，但毒粒中只能存在一种核酸 RNA DNA Viral Class DNA viruses RNA viruses viruses Viral Genome SsDNA dsDNA SsRNA SsRNA dsDNA dsRNA (Retroviruses) (Hepadnaviruses) 2012 Pearson Education.Inc. Retroviruses反转录病毒： contain an RNA genome in the Hepatitis B virus乙肝病毒： virion but replicate through a contains partially ds DNA in the DNA intermediate. virion but has an RNA intermediate in replication
9.1.1 Types of Viral Genomes The genomes of viruses: DNA or RNA, and some use both as their genomic material at different stages in their life cycle. However, only one type of nucleic acid is found in the virion of any particular type of virus. This can be single-stranded (ss), double-stranded (ds). 病毒基 因组可以是DNA或RNA, 可以是单链或双链, 但毒粒中只能存在一种核酸. Retroviruses 反转录病毒: contain an RNA genome in the virion but replicate through a DNA intermediate. Hepatitis B virus乙肝病毒: contains partially ds DNA in the virion but has an RNA intermediate in replication
上游充通大￥ SHANGHAI JIAO TONG UNIVERSITY 9.1.2 Viral Taxonomy/Classification分类 Host types ·Bacterial viruses /bacteriophage曦菌体 ·Animal viruses ·Plant viruses Genome types DNA virus,RNA virus,RNA-DNA virus Single strand,double strand Replication of genomic nucleic acid mRNA is the key molecule Chen Feng,Shanghai Jiao Tong University
Chen Feng, Shanghai Jiao Tong University 9.1.2 Viral Taxonomy/ Classification 分类 Host types • Bacterial viruses /bacteriophage噬菌体 • Animal viruses • Plant viruses Genome types • DNA virus, RNA virus, RNA-DNA virus • Single strand, double strand • Replication of genomic nucleic acid • mRNA is the key molecule
上游充通大学 SHANGHAI JIAO TONG UNIVERSITY 9.2 Nature of the Virion Size of virions Ranging from 0.02 to 0.3 um(20-300nm) Smallpox virus天花病毒is about200nmin diameter;poliovirus脊髓灰质炎病毒is only 28nm in diameter (about the size of ribosome). Chen Feng,Shanghai Jiao Tong University
Chen Feng, Shanghai Jiao Tong University 9.2 Nature of the Virion Ranging from 0.02 to 0.3 m (20-300nm). Smallpox virus天花病毒 is about 200nm in diameter; poliovirus脊髓灰质炎病毒is only 28nm in diameter (about the size of ribosome). Size of virions
上游充通大警 SHANGHAI JIAO TONG UNIVERSITY Genome size of virus The largest known viral genome,that of bacteriophage G,is 670 kb. Some viruses have genomes so small they contain less than 5 genes. Bacterial genomes:Most are between 1000 and 5000 kb,with the smallest known being 580kb. Chen Feng,Shanghai Jiao Tong University
Chen Feng, Shanghai Jiao Tong University Genome size of virus The largest known viral genome, that of bacteriophage G, is 670 kb. Some viruses have genomes so small they contain less than 5 genes. Bacterial genomes: Most are between 1000 and 5000 kb, with the smallest known being 580kb
上游充通大￥ SHANGHAI JIAO TONG UNIVERSITY Viral Structure Capsid:the protein shell that surrounds the genome of a virus particle衣壳 . Composed of a number of protein molecules arranged in a precise and highly repetitive pattern around the nucleic acid ©Capsomere:subunit of the capsid衣壳蛋白 Smallest morphological unit visible with an electron microscope 2012 Pearson Education,Inc Chen Feng,Shanghai Jiao Tong University
Chen Feng, Shanghai Jiao Tong University Viral Structure Capsid: the protein shell that surrounds the genome of a virus particle 衣壳 • Composed of a number of protein molecules arranged in a precise and highly repetitive pattern around the nucleic acid Capsomere: subunit of the capsid 衣壳蛋白 • Smallest morphological unit visible with an electron microscope © 2012 Pearson Education, Inc
