title: Noncoding RNA. piRNA-guided transposon cleavage initiates Zucchini-dependent, phased piRNA production.
abstract: PIWI-interacting RNAs (piRNAs) protect the animal germ line by silencing transposons. Primary piRNAs, generated from transcripts of genomic transposon "junkyards" (piRNA clusters), are amplified by the "ping-pong" pathway, yielding secondary piRNAs. We report that secondary piRNAs, bound to the PIWI protein Ago3, can initiate primary piRNA production from cleaved transposon RNAs. The first ~26 nucleotides (nt) of each cleaved RNA becomes a secondary piRNA, but the subsequent ~26 nt become the first in a series of phased primary piRNAs that bind Piwi, allowing piRNAs to spread beyond the site of RNA cleavage. The ping-pong pathway increases only the abundance of piRNAs, whereas production of phased primary piRNAs from cleaved transposon RNAs adds sequence diversity to the piRNA pool, allowing adaptation to changes in transposon sequence.
authors.affiliation: RNA Therapeutics Institute, Howard Hughes Medical Institute, University of Massachusetts Medical School, 368 Plantation Street, Worcester, MA 01605, USA. Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, 368 Plantation Street, Worcester, MA 01605, USA.
authors.forename: Bo W
authors.initials: BW
authors.lastname: Han
authors.affiliation: RNA Therapeutics Institute, Howard Hughes Medical Institute, University of Massachusetts Medical School, 368 Plantation Street, Worcester, MA 01605, USA. Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, 368 Plantation Street, Worcester, MA 01605, USA. Program in Bioinformatics and Integrative Biology, University of Massachusetts Medical School, 368 Plantation Street, Worcester, MA 01605, USA.
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.affiliation: RNA Therapeutics Institute, Howard Hughes Medical Institute, University of Massachusetts Medical School, 368 Plantation Street, Worcester, MA 01605, USA. Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, 368 Plantation Street, Worcester, MA 01605, USA.
authors.forename: Chengjian
authors.initials: C
authors.lastname: Li
authors.affiliation: Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, 368 Plantation Street, Worcester, MA 01605, USA. Program in Bioinformatics and Integrative Biology, University of Massachusetts Medical School, 368 Plantation Street, Worcester, MA 01605, USA. zhiping.weng@umassmed.edu phillip.zamore@umassmed.edu.
authors.forename: Zhiping
authors.initials: Z
authors.lastname: Weng
authors.affiliation: RNA Therapeutics Institute, Howard Hughes Medical Institute, University of Massachusetts Medical School, 368 Plantation Street, Worcester, MA 01605, USA. Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, 368 Plantation Street, Worcester, MA 01605, USA. zhiping.weng@umassmed.edu phillip.zamore@umassmed.edu.
authors.forename: Phillip D
authors.initials: PD
authors.lastname: Zamore
mesh_terms: D000818:Animals; D060565:Argonaute Proteins / Q000235:genetics / Q000378:metabolism*; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000235:genetics / Q000378:metabolism*; D004722:Endoribonucleases / Q000235:genetics / Q000378:metabolism*; D005260:Female; D005854:Germ Cells / Q000378:metabolism; D008297:Male; D053858:Metabolic Networks and Pathways; D051379:Mice; D010053:Ovary / Q000378:metabolism; D010448:Peptide Initiation Factors / Q000235:genetics / Q000378:metabolism*; D059367:RNA Cleavage; D034741:RNA, Small Interfering / Q000096:biosynthesis / Q000378:metabolism*; D018626:Retroelements; D013737:Testis / Q000378:metabolism; D000094704:RNA, Guide, CRISPR-Cas Systems
chemical_list: D060565:Argonaute Proteins; D029721:Drosophila Proteins; D004722:Endoribonucleases; D010448:Peptide Initiation Factors; D034741:RNA, Small Interfering; D018626:Retroelements; D000094704:RNA, Guide, CRISPR-Cas Systems; C518392:AGO3 protein, Drosophila; C436124:aub protein, Drosophila; C521347:Zuc protein, Drosophila