title: piRNA production requires heterochromatin formation in Drosophila.
abstract: Protecting the genome from transposable element (TE) mobilization is critical for germline development. In Drosophila, Piwi proteins and their bound small RNAs (piRNAs) provide a potent defense against TE activity. TE targeting piRNAs are processed from TE-dense heterochromatic loci termed piRNA clusters. Although piRNA biogenesis from cluster precursors is beginning to be understood, little is known about piRNA cluster transcriptional regulation. Here, we show that deposition of histone 3 lysine 9 by the methyltransferase dSETDB1 (egg) is required for piRNA cluster transcription. In the absence of dSETDB1, cluster precursor transcription collapses in germline and somatic gonadal cells and TEs are activated, resulting in germline loss and a block in germline stem cell differentiation. We propose that heterochromatin protects the germline by activating the piRNA pathway.
authors.affiliation: Department of Cell Biology, Howard Hughes Medical Institute and Kimmel Center for Biology and Medicine, Skirball Institute, New York University School of Medicine, New York, NY 10016, USA.
authors.forename: Prashanth
authors.initials: P
authors.lastname: Rangan
authors.forename: Colin D
authors.initials: CD
authors.lastname: Malone
authors.forename: Caryn
authors.initials: C
authors.lastname: Navarro
authors.forename: Sam P
authors.initials: SP
authors.lastname: Newbold
authors.forename: Patrick S
authors.initials: PS
authors.lastname: Hayes
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; D042002:Chromatin Assembly and Disassembly; D004251:DNA Transposable Elements; D004331:Drosophila melanogaster / Q000166:cytology / Q000235:genetics* / Q000378:metabolism; D005786:Gene Expression Regulation; D006570:Heterochromatin / Q000378:metabolism*; D008969:Molecular Sequence Data; D034741:RNA, Small Interfering / Q000096:biosynthesis* / Q000235:genetics; D014158:Transcription, Genetic
chemical_list: D004251:DNA Transposable Elements; D006570:Heterochromatin; D034741:RNA, Small Interfering