Sex-lethal is a target of Bruno-mediated translational repression in promoting the differentiation of stem cell progeny during Drosophila oogenesis

摘要

TheRNARecognitionMotif(RRM)typeRNAbindingproteinBrunoisrequiredforthedifferentiationofcystoblasts,thecommitteddaughtersofgermlinestemcellsintheemDrosophila/emovary.TounderstandhowBrunocontrolscystoblastdifferentiation,weusedabioinformaticsapproachtoidentifypotentialmRNAtargetsofBruno.OnesuchtargetistheemSex-lethal/em(emSxl/em)transcriptMS11,whichcontainsfourBrunoResponseElements(BREs)inits3prime;untranslatedregion.ElectrophoresismobilityshiftassaysdemonstratedthatBrunospecificallybindstotheBREsofemSxl/emMS11mRNA.TaggedtransgenicemSxl/emMS11cDNAconstructswereusedtoshowthatBrunorepressesthetranslationoftheemSxl/emMS11mRNAviatheBRE-containingregioninthe3prime;UTR.ThelackofeitherBrunoortheBRE-containingregionleadstooverexpressionofSXL,whichinturncausesdefectsincystoblastdifferentiationsimilartotheemBruno/emmutantphenotype.Therefore,emSxl/emMS11representsanoveltargetofBruno-mediatedtranslationalrepressionrequiredforcystoblastdifferentiation./p/div