The Drosophila putative histone acetyltransferase Enok maintains female germline stem cells through regulating Bruno and the niche

摘要

Maintenanceofadultstemcellsislargelydependentonthebalancebetweentheirself-renewalanddifferentiation.TheemDrosophila/emovariangermlinestemcells(GSCs)provideapowerfuleminvivo/emsystemforstudyingstemcellfateregulation.IthasbeenshownthatmaintainingtheGSCpopulationinvolvesbothgeneticandepigeneticmechanisms.Althoughtheroleofepigeneticregulationinthisprocessisevident,theunderlyingmechanismsremaintobefurtherexplored.Inthisstudy,wefindthatEnokimushroom(Enok),aemDrosophila/emputativeMYSTfamilyhistoneacetyltransferasecontrolsGSCmaintenanceintheovaryatmultiplelevels.RemovalorknockdownofEnokinthegermlinecausesaGSCmaintenancedefect.Furtherstudiesshowthatthecell-autonomousroleofEnokinmaintainingGSCsisnotdependentontheBMP/Bampathway.Interestingly,molecularstudiesrevealanectopicexpressionofBruno,anRNAbindingprotein,intheGSCsandtheirdifferentiatingdaughtercellselicitedbythegermlineEnokdeficiency.MisexpressionofBrunoinGSCsandtheirimmediatedescendantsresultsinaGSClossthatcanbeexacerbatedbyincorporatingonecopyofemenok/emmutantallele.ThesedatasuggestaroleforBrunoinEnok-controlledGSCmaintenance.Inaddition,weobservethatEnokisrequiredformaintainingGSCsnon-autonomously.Compromisedexpressionofemenok/eminthenichecellsimpairsthenichemaintenanceandBMPsignaloutput,therebycausingdefectiveGSCmaintenance.Thisisthefirstdemonstrationthatthenichesizecontrolrequiresanepigeneticmechanism.Takentogether,studiesinthispaperprovidenewinsightsintotheGSCfateregulation./p/div