1931-OswaldT.Averyfound that bacterialtransformation can occur in the culture mediumwithoutusinganimalsHeat-killedScomponentsinmediumTimeLivingRformLivingSformFig.6.5a6-11
Copyright © The McGraw-Hill Companies, Inc. Permission required to reproduce or display 6-11 Fig. 6.5 a 1931 – Oswald T. Avery Oswald T. Avery found that bacterial found that bacterial transformation can occur in the culture medium transformation can occur in the culture medium without using animals. without using animals
Purification of the“transforming principle”PurificationHeat-killedScomponentsTransformingprincipleFig.6.5b6-12
Copyright © The McGraw-Hill Companies, Inc. Permission required to reproduce or display 6-12 Fig. 6.5 b Purification of the “transforming principle” Purification Transforming principle
1944-Oswald T.Avery, Colin MacLeod, and MaclynMcCarty found that the transforming principle is DNA,but not proteins,RNAs,lipids or polysaccharides.ScellsIntroduce intoProteaseProteinRcellsdestroyed(Transformation)RNaseRNAIntroduceintoScellsRcellsdestroyed(Transformation)DNaseDNAIntroduceintoRcellsRcellsdestroyed(Notransformation)ScellsUltracentrifugationFatsIntroduceintoRcells(Transformation)eliminatedTransformingIndicatesPhysical andprinciplepredominancechemicalofDNAanalysisFig.6.5c6-13
Copyright © The McGraw-Hill Companies, Inc. Permission required to reproduce or display 6-13 Fig. 6.5 c 1944 – Oswald T. Avery Oswald T. Avery, Colin MacLeod Colin MacLeod, and Maclyn McCarty McCarty found that the transforming principle is DNA, found that the transforming principle is DNA, but not proteins, but not proteins, RNAs, lipids or polysaccharides. , lipids or polysaccharides. Transforming principle
The Hershey-Chase experiment1952-Alfred Hershey andMartha Chasetestedwhether the injectedmaterial is composed ofprotein or DNA.Waring blenderexperimentusing T2bacteriophage andbacteria.Martha Chase Aifred Hershey(1927-2003)(1908-1997)6-14
Copyright © The McGraw-Hill Companies, Inc. Permission required to reproduce or display 6-14 1952 – Alfred Hershey Alfred Hershey and Martha Chase Martha Chase tested whether the injected whether the injected material is composed of material is composed of protein or DNA. protein or DNA. Waring blender blender experiment experiment using T2 using T2 bacteriophage bacteriophage and bacteria. bacteria. The Hershey The Hershey-Chase experiment Chase experiment Martha Chase (1927-2003) Alfred Hershey (1908-1997)
1.PhageattachesProteincoattobacterium(host).DNACellburstsreleasingnewphage.公专2FCore2.PhageinjectsHostcell wallitsgenes intohostcell.NT2phage4.Phageparticles3.PhageDNAreplicatesassemble.newphageproteinsaremadeFig.6.66-15
Copyright © The McGraw-Hill Companies, Inc. Permission required to reproduce or display 6-15 Fig. 6.6