title: A role for transcription from a piRNA cluster in de novo piRNA production.
abstract: PIWI-interacting RNAs (piRNAs) are at the heart of the nucleic acid-based adaptive immune system against transposons in animal gonads. To date, how the piRNA pathway senses an element as a substrate and how de novo piRNA production is initiated remain elusive. Here, by utilizing a GFP transgene, we screened and obtained clonal silkworm BmN4 cell lines producing massively amplified GFP-derived piRNAs capable of silencing GFP in trans. In multiple independent cell lines where GFP expression was silenced by the piRNA pathway, we detected a common transcript from an endogenous piRNA cluster, in which a part of the cluster is uniquely fused with an antisense GFP sequence. Bioinformatic analyses suggest that the fusion transcript is a source of GFP primary piRNAs. Our data implicate a role for transcription from a piRNA cluster in initiating de novo piRNA production against a new insertion.
authors.affiliation: Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo, Japan.
authors.forename: Shinpei
authors.initials: S
authors.lastname: Kawaoka
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Mitsutake
authors.forename: Takashi
authors.initials: T
authors.lastname: Kiuchi
authors.forename: Maki
authors.initials: M
authors.lastname: Kobayashi
authors.forename: Mayu
authors.initials: M
authors.lastname: Yoshikawa
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Suzuki
authors.forename: Sumio
authors.initials: S
authors.lastname: Sugano
authors.forename: Toru
authors.initials: T
authors.lastname: Shimada
authors.forename: Jun
authors.initials: J
authors.lastname: Kobayashi
authors.forename: Yukihide
authors.initials: Y
authors.lastname: Tomari
authors.forename: Susumu
authors.initials: S
authors.lastname: Katsuma
mesh_terms: D000818:Animals; D012831:Bombyx / Q000235:genetics / Q000378:metabolism; D002460:Cell Line; D005260:Female; D020868:Gene Silencing; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D010053:Ovary / Q000378:metabolism; D012326:RNA Splicing / Q000235:genetics; D034741:RNA, Small Interfering / Q000096:biosynthesis* / Q000235:genetics* / Q000378:metabolism; D019076:Transgenes
chemical_list: D034741:RNA, Small Interfering; D049452:Green Fluorescent Proteins