title: piRNA pathway is not required for antiviral defense in Drosophila melanogaster.
abstract: Since its discovery, RNA interference has been identified as involved in many different cellular processes, and as a natural antiviral response in plants, nematodes, and insects. In insects, the small interfering RNA (siRNA) pathway is the major antiviral response. In recent years, the Piwi-interacting RNA (piRNA) pathway also has been implicated in antiviral defense in mosquitoes infected with arboviruses. Using Drosophila melanogaster and an array of viruses that infect the fruit fly acutely or persistently or are vertically transmitted through the germ line, we investigated in detail the extent to which the piRNA pathway contributes to antiviral defense in adult flies. Following virus infection, the survival and viral titers of Piwi, Aubergine, Argonaute-3, and Zucchini mutant flies were similar to those of wild type flies. Using next-generation sequencing of small RNAs from wild type and siRNA mutant flies, we showed that no viral-derived piRNAs were produced in fruit flies during different types of viral infection. Our study provides the first evidence, to our knowledge, that the piRNA pathway does not play a major role in antiviral defense in adult Drosophila and demonstrates that viral-derived piRNA production depends on the biology of the host-virus combination rather than being part of a general antiviral process in insects.
authors.affiliation: Viruses and RNA Interference, Institut Pasteur, CNRS Unité Mixte de Recherche 3569, 75724 Paris Cedex 15, France; Sorbonne Universités, Université Pierre et Marie Curie, Institut de Formation Doctorale, 75252 Paris Cedex 05, France;
authors.forename: Marine
authors.initials: M
authors.lastname: Petit
authors.affiliation: Viruses and RNA Interference, Institut Pasteur, CNRS Unité Mixte de Recherche 3569, 75724 Paris Cedex 15, France; vanesa.mongelli@pasteur.fr carla.saleh@pasteur.fr.
authors.forename: Vanesa
authors.initials: V
authors.lastname: Mongelli
authors.affiliation: Viruses and RNA Interference, Institut Pasteur, CNRS Unité Mixte de Recherche 3569, 75724 Paris Cedex 15, France;
authors.forename: Lionel
authors.initials: L
authors.lastname: Frangeul
authors.affiliation: Viruses and RNA Interference, Institut Pasteur, CNRS Unité Mixte de Recherche 3569, 75724 Paris Cedex 15, France;
authors.forename: Hervé
authors.initials: H
authors.lastname: Blanc
authors.affiliation: Department of Genetics, University of Cambridge, Cambridge CB2 3EH, United Kingdom.
authors.forename: Francis
authors.initials: F
authors.lastname: Jiggins
authors.affiliation: Viruses and RNA Interference, Institut Pasteur, CNRS Unité Mixte de Recherche 3569, 75724 Paris Cedex 15, France; vanesa.mongelli@pasteur.fr carla.saleh@pasteur.fr.
authors.forename: Maria-Carla
authors.initials: MC
authors.lastname: Saleh
mesh_terms: D000818:Animals; D004331:Drosophila melanogaster / Q000276:immunology* / Q000821:virology*; D054884:Host-Pathogen Interactions; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics*; D014780:Viruses / Q000235:genetics* / Q000472:pathogenicity
chemical_list: D034741:RNA, Small Interfering
keywords: antiviral RNAi; insect; piRNA; small RNA; virus