title: A translation-independent role of oskar RNA in early Drosophila oogenesis.
abstract: The Drosophila maternal effect gene oskar encodes the posterior determinant responsible for the formation of the posterior pole plasm in the egg, and thus of the abdomen and germline of the future fly. Previously identified oskar mutants give rise to offspring that lack both abdominal segments and a germline, thus defining the ;posterior group phenotype'. Common to these classical oskar alleles is that they all produce significant amounts of oskar mRNA. By contrast, two new oskar mutants in which oskar RNA levels are strongly reduced or undetectable are sterile, because of an early arrest of oogenesis. This egg-less phenotype is complemented by oskar nonsense mutant alleles, as well as by oskar transgenes, the protein-coding capacities of which have been annulled. Moreover, we show that expression of the oskar 3' untranslated region (3'UTR) is sufficient to rescue the egg-less defect of the RNA null mutant. Our analysis thus reveals an unexpected role for oskar RNA during early oogenesis, independent of Oskar protein. These findings indicate that oskar RNA acts as a scaffold or regulatory RNA essential for development of the oocyte.
authors.affiliation: European Molecular Biology Laboratory, Meyerhofstrasse 1, 69117 Heidelberg, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Jenny
authors.forename: Olivier
authors.initials: O
authors.lastname: Hachet
authors.forename: Péter
authors.initials: P
authors.lastname: Závorszky
authors.forename: Anna
authors.initials: A
authors.lastname: Cyrklaff
authors.forename: Matthew D J
authors.initials: MD
authors.lastname: Weston
authors.forename: Daniel St
authors.initials: DS
authors.lastname: Johnston
authors.forename: Miklós
authors.initials: M
authors.lastname: Erdélyi
authors.forename: Anne
authors.initials: A
authors.lastname: Ephrussi
mesh_terms: D020413:3' Untranslated Regions; D000818:Animals; D017931:DNA Primers; D004330:Drosophila / Q000502:physiology*; D029721:Drosophila Proteins / Q000235:genetics*; D005260:Female; D018507:Gene Expression Regulation, Developmental; D005816:Genetic Complementation Test; D006579:Heterozygote; D009865:Oocytes / Q000502:physiology*; D009866:Oogenesis / Q000235:genetics / Q000502:physiology*; D012313:RNA / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014158:Transcription, Genetic
chemical_list: D020413:3' Untranslated Regions; D017931:DNA Primers; D029721:Drosophila Proteins; C091675:osk protein, Drosophila; D012313:RNA