662Cell150,August3,2012©2012ElsevierInc.DOI10.1016/j.cell.2012.07.016SnapShot:EndogenousRNAiMachineryandMechanismsMathieuFlamandandThomasF.DuchaineGoodmanCancerResearchCentre,DepartmentofBiochemisty,McGillUniversity,Montreal,QuebecH3A1A3,CanadaSeeonlineversionforlegendandreferences.Features/PropertiesSourceofTrigger/TargetsKnownBiogenesisRequirementsSize(nt)5´bias2´-O-Meat3´5´phosphatestatusArgonauteSourceoftriggerTargetRNATargettissueSubstratesandfunctionsSilencingmechanismERGO-126GRNA26G+monophosphateERGO-1mRNAs,aberranttranscriptscisgermline(oocyte)andsoma(embryo)generegulation,transcriptsurveil-lancePTGS,recruitmentofRdRPmodulesforproductionof2osiRNAs(22Gs),TGSandnuclearRNAi(viaWAGOs):histonemodification,chroma-tinremodelingDicer:DCR-1;RdRP:RRF-3;others:ERI-5,DRH-3,ERI-1,ERI-3,HENN-1ALG-3/426GRNA26G-monophosphateALG-3/4mRNAs,aberranttranscriptscisgermline(sperm)generegulation,improverobustnessofspermcellstotemperature(proposed)PTGS,recruitmentofRdRPmodulesforproductionof2osiRNAs(22Gs),TGS(viaWAGOs)Dicer:DCR-1;RdRP:RRF-3;others:DRH-3,ERI-1WAGO-22G22Gn.d.triphosphateWAGOstranscriptstargetedbyaprimaryevent(26G,21U-piRNA,miRNA)cisandtransgermlineandsomaticsilencingamplifica-tionofothersmallRNApathways(26GsiRNAs,21URNAs,andinsomecasesmiRNAs)PTGS,andTGSbynuclearRNAi:histonemodification,chroma-tinremodelingDicer:notrequired;RdRP:RRF-1,EGO-1;others:EKL-1,DRH-3CSR-122G22G-triphosphateCSR-1germlineexpressedvarioustranscriptscisgermlinegeneregulation,genomesurveil-lance,chomosomeorganization,cen-tromereassembly,selfversusnonselfdiscriminationchromatinremodeling,butalsodirectsanon-silencingmechanismDicer:notrequired;RdRP:RRF-1,EGO-1;others:EKL-1,DRH-321U-piRNA21U+monophosphatePIWI-cladePRG-1andPRG-2transposons,specifictranscriptcisandtransgermlinegermlinemainte-nanceandfertility,transposonsilenc-ing,inheritableepigeneticsilencingPTGS,feedsintotheWAGO-22GRNAsandnuclearRNAiDicer:notrequired;RdRP:none;others:upstreamDNAmotif,HENN-1casiRNA24A+monophosphateAGO6/AGO4nasce...
