title: Mago Nashi, Tsunagi/Y14, and Ranshi form a complex that influences oocyte differentiation in Drosophila melanogaster.
abstract: During Drosophila melanogaster oogenesis, a germline stem cell divides forming a cyst of 16 interconnected cells. One cell enters the oogenic pathway, and the remaining 15 differentiate as nurse cells. Although directed transport and localization of oocyte differentiation factors within the single cell are indispensible for selection, maintenance, and differentiation of the oocyte, the mechanisms regulating these events are poorly understood. Mago Nashi and Tsunagi/Y14, core components of the exon junction complex (a multiprotein complex assembled on spliced RNAs), are essential for restricting oocyte fate to a single cell and for localization of oskar mRNA. Here we provide evidence that Mago Nashi and Tsunagi/Y14 form an oogenic complex with Ranshi, a protein with a zinc finger-associated domain and zinc finger domains. Genetic analyses of ranshi reveal that (1) 16-cell cysts are formed, (2) two cells retain synaptonemal complexes, (3) all cells have endoreplicated DNA (as observed in nurse cells), and (4) oocyte-specific cytoplasmic markers accumulate and persist within a single cell but are not localized within the posterior pole of the presumptive oocyte. Our results indicate that Ranshi interacts with the exon junction complex to localize components essential for oocyte differentiation within the posterior pole of the presumptive oocyte.
authors.affiliation: Cell and Molecular Biology Graduate Program, Institute for Cell and Molecular Biology, University of Texas at Austin, Austin, TX 78712, USA.
authors.forename: Jordan P
authors.initials: JP
authors.lastname: Lewandowski
authors.forename: Kathy B
authors.initials: KB
authors.lastname: Sheehan
authors.forename: Paul E
authors.initials: PE
authors.lastname: Bennett
authors.forename: Robert E
authors.initials: RE
authors.lastname: Boswell
mesh_terms: D000818:Animals; D019521:Body Patterning; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D002454:Cell Differentiation; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000378:metabolism*; D017344:Genes, Insect; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D009865:Oocytes / Q000166:cytology* / Q000378:metabolism; D009866:Oogenesis / Q000502:physiology*; D010641:Phenotype; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D002352:Carrier Proteins; D029721:Drosophila Proteins; C107372:Mago protein, Drosophila; D009687:Nuclear Proteins; D016601:RNA-Binding Proteins; C549533:ranshi protein, Drosophila; C440016:tsu protein, Drosophila