Bruno regulates gurken during Drosophila oogenesis.
Translational regulation of localized transcripts is a powerful mechanism to control the precise timing and localization of protein expression within a cell. In the Drosophila germline, oskar transcript must be translationally repressed until its localization at the posterior pole of the oocyte, as ectopic production of Oskar causes severe patterning defects. Translational repression of oskar mRNA is mediated by the RNA-binding protein Bruno, which binds to specific motifs in the oskar 3'UTR. Here we show that Bruno over-expression causes defects in antero-posterior and dorso-ventral patterning, consistent with a role of Bruno in both oskar and gurken mRNA regulation. We also show that Bruno and gurken interact genetically. Finally, we show that Bruno binds specifically to the gurken 3'UTR and that the dorso-ventral defects caused by Bruno over-expression are due to a reduction of Gurken levels in the oocyte. We conclude that Bruno plays similar roles in translational regulation of gurken and oskar.
Filardo
Paolo
P
Developmental Biology Programme, European Molecular Biology Laboratory, Meyerhofstrasse 1, 69117 Heidelberg, Germany.
Ephrussi
Anne
A
D020413:3' Untranslated Regions; D000818:Animals; D030801:Animals, Genetically Modified; D004330:Drosophila / Q000502:physiology*; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D005260:Female; D018628:Gene Dosage; D018507:Gene Expression Regulation, Developmental; D009865:Oocytes / Q000473:pathology; D009866:Oogenesis / Q000235:genetics*; D010053:Ovary / Q000254:growth & development; D010063:Ovum / Q000502:physiology; D012333:RNA, Messenger / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D016211:Transforming Growth Factor alpha / Q000235:genetics* / Q000378:metabolism; D015291:Transforming Growth Factors / Q000235:genetics* / Q000378:metabolism
D020413:3' Untranslated Regions; D029721:Drosophila Proteins; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D016211:Transforming Growth Factor alpha; C093437:bru1 protein, Drosophila; C083730:grk protein, Drosophila; C091675:osk protein, Drosophila; D015291:Transforming Growth Factors