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