title: Vreteno, a gonad-specific protein, is essential for germline development and primary piRNA biogenesis in Drosophila.
abstract: In Drosophila, Piwi proteins associate with Piwi-interacting RNAs (piRNAs) and protect the germline genome by silencing mobile genetic elements. This defense system acts in germline and gonadal somatic tissue to preserve germline development. Genetic control for these silencing pathways varies greatly between tissues of the gonad. Here, we identified Vreteno (Vret), a novel gonad-specific protein essential for germline development. Vret is required for piRNA-based transposon regulation in both germline and somatic gonadal tissues. We show that Vret, which contains Tudor domains, associates physically with Piwi and Aubergine (Aub), stabilizing these proteins via a gonad-specific mechanism that is absent in other fly tissues. In the absence of vret, Piwi-bound piRNAs are lost without changes in piRNA precursor transcript production, supporting a role for Vret in primary piRNA biogenesis. In the germline, piRNAs can engage in an Aub- and Argonaute 3 (AGO3)-dependent amplification in the absence of Vret, suggesting that Vret function can distinguish between primary piRNAs loaded into Piwi-Aub complexes and piRNAs engaged in the amplification cycle. We propose that Vret plays an essential role in transposon regulation at an early stage of primary piRNA processing.
authors.affiliation: HHMI and Kimmel Center for Biology and Medicine at Skirball Institute, Department of Cell Biology, New York University School of Medicine, New York, NY 10016, USA.
authors.forename: Andrea L
authors.initials: AL
authors.lastname: Zamparini
authors.forename: Marie Y
authors.initials: MY
authors.lastname: Davis
authors.forename: Colin D
authors.initials: CD
authors.lastname: Malone
authors.forename: Eric
authors.initials: E
authors.lastname: Vieira
authors.forename: Jiri
authors.initials: J
authors.lastname: Zavadil
authors.forename: Ravi
authors.initials: R
authors.lastname: Sachidanandam
authors.forename: Gregory J
authors.initials: GJ
authors.lastname: Hannon
authors.forename: Ruth
authors.initials: R
authors.lastname: Lehmann
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D029721:Drosophila Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D004331:Drosophila melanogaster / Q000196:embryology* / Q000235:genetics* / Q000378:metabolism; D005260:Female; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D020868:Gene Silencing / Q000502:physiology; D005854:Germ Cells / Q000254:growth & development* / Q000378:metabolism; D006066:Gonads / Q000378:metabolism*; D008297:Male; D046228:Microarray Analysis; D009928:Organ Specificity / Q000235:genetics; D010053:Ovary / Q000166:cytology / Q000254:growth & development / Q000378:metabolism; D017434:Protein Structure, Tertiary / Q000502:physiology; D012323:RNA Processing, Post-Transcriptional / Q000235:genetics / Q000502:physiology; D034741:RNA, Small Interfering / Q000096:biosynthesis*
chemical_list: D029721:Drosophila Proteins; D034741:RNA, Small Interfering; C562076:Vret protein, Drosophila