AAAAAAAADcr1RITSCLRCReplisomeInitiationInitiationDicerAAAAAAAARDE-1RDE-1RdRPRDRCHRDE-1/WAGO-9HRDE-1Swi6GUUGGHRDE-1/WAGO-9GPRG-1RdRPRdRPAAAAGGGAAAACSR-1GCSR-1HPL-2GKinetochoreformationGermline-expressedgenesAmplificationAmplificationloopAmplifcationSilencingSilencingSilencingAmplificationDCL3FlamencopiRNAclusterUMammals(senseprecursor)Drosophila(antisenseprecursor)DrosophilaMouseInitiationUAUUAUAAUUU?SomaRhinoPIWIPIWIGermlineHP1Double-strandbreakRepairDouble-strandbreakRepairfociformationC.elegansMiceandDrosophilaPlantsS.pombeAgo1Ago1Ago1??Arb1/2Arb1/2RDE-126GsiRNAGGG22GsiRNApiRNA22GsiRNA24-mersiRNAAGGGNUCLEUSCYTOPLASMPolIIPolIIPolIIPolIIPolIIPolIIPolIIPolIIPolIIPolIIPolIIPolIIPolV?PolIVPolIVPolIIMeMeMeMeMeMeMeMeMeMeMeMIWI2MIWI2DICER/DROSHADCL2/3/4RDR2/6AGO2AGO4AGO4DRM2/DRD1RDR2KYPCMT3Amplification22-merdiRNAMIWI2MIWI2MIWI2MILIMILIMILIMILIAubAubAubAgo3Ago3Ago3PIWI/AubAmplification(ping-pongcycle)InitiationmRNAsilencingSilencingAApiRNAdual-strandclusterspiRNAdual-strandclustersH3K9meH3K9meDNMT3DNMT3SnapShot:SmallRNA-MediatedEpigeneticModificationsMikelZaratiegui1andRobertA.Martienssen21DepartmentofMolecularBiologyandBiochemistry,RutgersUniversity,Piscataway,NJ08854,USA2HowardHughesMedicalInstitute-GordonandBettyMooreFoundation,WatsonSchoolofBiologicalSciences,ColdSpringHarborLaboratory,ColdSpringHarbor,NY11724,USASeeonlineversionforlegendandreferences.456Cell151,October12,2012©2012ElsevierInc.DOIhttp://dx.doi.org/10.1016/j.cell.2012.10.001456.e1Cell151,October12,2012©2012ElsevierInc.DOIhttp://dx.doi.org/10.1016/j.cell.2012.10.001SnapShot:SmallRNA-MediatedEpigeneticModificationsMikelZaratiegui1andRobertA.Martienssen21DepartmentofMolecularBiologyandBiochemistry,RutgersUniversity,Piscataway,NJ08854,USA2HowardHughesMedicalInstitute-GordonandBettyMooreFoundation,WatsonSchoolofBiologicalSciences,ColdSpringHarborLaboratory,ColdSpringHarbor,NY11724,USAThefunctionofchromatinintranscriptionalcontrolandchromosomalarchitectureisregulatedbyadiversesetofRNAcomponentsinalleukar...
