title: Abundant primary piRNAs, endo-siRNAs, and microRNAs in a Drosophila ovary cell line.
abstract: Piwi proteins, a subclass of Argonaute-family proteins, carry approximately 24-30-nt Piwi-interacting RNAs (piRNAs) that mediate gonadal defense against transposable elements (TEs). We analyzed the Drosophila ovary somatic sheet (OSS) cell line and found that it expresses miRNAs, endogenous small interfering RNAs (endo-siRNAs), and piRNAs in abundance. In contrast to intact gonads, which contain mixtures of germline and somatic cell types that express different Piwi-class proteins, OSS cells are a homogenous somatic cell population that expresses only PIWI and primary piRNAs. Detailed examination of its TE-derived piRNAs and endo-siRNAs revealed aspects of TE defense that do not rely upon ping-pong amplification. In particular, we provide evidence that a subset of piRNA master clusters, including flamenco, are specifically expressed in OSS and ovarian follicle cells. These data indicate that the restriction of certain TEs in somatic gonadal cells is largely mediated by a primary piRNA pathway.
authors: Department of Molecular Biology, Massachusetts General Hospital, Boston, 02114, USA. nlau@brandeis.edu
authors: Nelson C
authors: NC
authors: Lau
authors: Nicolas
authors: N
authors: Robine
authors: Raquel
authors: R
authors: Martin
authors: Wei-Jen
authors: WJ
authors: Chung
authors: Yuzo
authors: Y
authors: Niki
authors: Eugene
authors: E
authors: Berezikov
authors: Eric C
authors: EC
authors: Lai
mesh_terms: D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D004330:Drosophila / Q000235:genetics* / Q000378:metabolism; D005260:Female; D005786:Gene Expression Regulation; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism; D008954:Models, Biological; D008969:Molecular Sequence Data; D010053:Ovary / Q000378:metabolism*; D012322:RNA Precursors / Q000235:genetics* / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics* / Q000378:metabolism; D012689:Sequence Homology, Nucleic Acid
chemical_list: D035683:MicroRNAs; D012322:RNA Precursors; D034741:RNA, Small Interfering