title: zucchini and squash encode two putative nucleases required for rasiRNA production in the Drosophila germline.
abstract: RNAi is a widespread mechanism by which organisms regulate gene expression and defend their genomes against viruses and transposable elements. Here we report the identification of Drosophila zucchini (zuc) and squash (squ), which function in germline RNAi processes. Zuc and Squ contain domains with homologies to nucleases. Mutant females are sterile and show dorsoventral patterning defects during oogenesis. In addition, Oskar protein is ectopically expressed in early oocytes, where it is normally silenced by RNAi mechanisms. Zuc and Squ localize to the perinuclear nuage and interact with Aubergine, a PIWI class protein. Mutations in zuc and squ induce the upregulation of Het-A and Tart, two telomere-specific transposable elements, and the expression of Stellate protein in the Drosophila germline. We show that these defects are due to the inability of zuc and squ mutants to produce repeat-associated small interfering RNAs.
authors.affiliation: Howard Hughes Medical Institute, Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA.
authors.forename: Attilio
authors.initials: A
authors.lastname: Pane
authors.forename: Kristina
authors.initials: K
authors.lastname: Wehr
authors.forename: Trudi
authors.initials: T
authors.lastname: Schüpbach
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D015152:Blotting, Northern; D015153:Blotting, Western; D004251:DNA Transposable Elements / Q000502:physiology; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D004625:Embryo, Nonmammalian / Q000378:metabolism*; D004720:Endonucleases / Q000235:genetics / Q000378:metabolism*; D004722:Endoribonucleases / Q000235:genetics / Q000378:metabolism*; D005260:Female; D015966:Gene Expression Regulation, Fungal; D015683:Gene Products, gag / Q000378:metabolism; D005854:Germ Cells / Q000166:cytology / Q000378:metabolism*; D047468:Immunoprecipitation; D008297:Male; D008969:Molecular Sequence Data; D009154:Mutation; D009865:Oocytes / Q000166:cytology / Q000378:metabolism; D009866:Oogenesis / Q000502:physiology*; D010448:Peptide Initiation Factors / Q000378:metabolism; D012331:RNA, Fungal / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000494:pharmacology*; D017386:Sequence Homology, Amino Acid; D016211:Transforming Growth Factor alpha / Q000378:metabolism
chemical_list: D004251:DNA Transposable Elements; D029721:Drosophila Proteins; D015683:Gene Products, gag; C103996:HeT-A-gag protein, Drosophila; D010448:Peptide Initiation Factors; D012331:RNA, Fungal; D012333:RNA, Messenger; D034741:RNA, Small Interfering; C469435:TART-element-gag protein, Drosophila; D016211:Transforming Growth Factor alpha; C436124:aub protein, Drosophila; C083730:grk protein, Drosophila; C091675:osk protein, Drosophila; D004720:Endonucleases; D004722:Endoribonucleases; C521348:Squ protein, Drosophila; C521347:Zuc protein, Drosophila