Chapter1Viruses

Chapter1Viruses•Virus:非细胞结构（noncellular），专性寄生的超微小微生物•virion（病毒粒子，毒粒）：完整的具有感染力的病毒体•病毒的特性与宿主细胞相关•病毒可以给宿主带来新的特性ClassificationofVirusesVirusescanhaveeitherDNAorRNAasgeneticmaterial•Accordingtohostsvirusesinfect:–Bacterialviruses(Bacteriophageor噬菌体）–Animalviruses(wellstudied)–Plantviruses(lessstudied)–Others•Accordingtonucleicacidstructures:–DNAviruses–RNAviruses–RNADNAvirusesNatureofthevirionVirusSize:20nmto300nmLargestvirus:Smallpox(天花病毒)is200nmmamavirus（Nature,1-5(2008)Smallestvirus:Poliovirus(脊髄灰质炎病毒)is28nmVirusgenome:Smallerthanthoseofcells,thelargestknownviralgenome:vaccinia(牛痘)isonly190Kbp.Bacterialgenomes:1000-9000KbpBLScolaetal.Nature000,1-5(2008)doi:10.1038/nature07218DifferentmorphologicalaspectsofMamavirusandSputnik.VirusStructureVirusesconsistofnucleicacids,capsid（衣壳）,and/orenvelope（被膜）.VirusMorphology•甲型H1N1病毒VirusLifeCycleHowabacteriophageinjectsitsnucleicacidintoahostcell?