TY - JOUR TI - Environmentally-induced epigenetic conversion of a piRNA cluster AU - Casier, Karine AU - Delmarre, Valérie AU - Gueguen, Nathalie AU - Hermant, Catherine AU - Viodé, Elise AU - Vaury, Chantal AU - Ronsseray, Stéphane AU - Brasset, Emilie AU - Teysset, Laure AU - Boivin, Antoine A2 - Nilsen, Timothy W A2 - Manley, James L VL - 8 PY - 2019 DA - 2019/03/15 SP - e39842 C1 - eLife 2019;8:e39842 DO - 10.7554/eLife.39842 UR - https://doi.org/10.7554/eLife.39842 AB - Transposable element (TE) activity is repressed in animal gonads by PIWI-interacting RNAs (piRNAs) produced by piRNA clusters. Current models in flies propose that germinal piRNA clusters are functionally defined by the maternal inheritance of piRNAs produced during the previous generation. Taking advantage of an inactive, but ready to go, cluster of P-element derived transgene insertions in Drosophila melanogaster, we show here that raising flies at high temperature (29°C) instead of 25°C triggers the stable conversion of this locus from inactive into actively producing functional piRNAs. The increase of antisense transcripts from the cluster at 29°C combined with the requirement of transcription of euchromatic homologous sequences, suggests a role of double stranded RNA in the production of de novo piRNAs. This report describes the first case of the establishment of an active piRNA cluster by environmental changes in the absence of maternal inheritance of homologous piRNAs. Editorial note: This article has been through an editorial process in which the authors decide how to respond to the issues raised during peer review. The Reviewing Editor's assessment is that all the issues have been addressed (see decision letter). KW - epigenetics KW - germline KW - non coding small RNA KW - transposable element KW - temperature KW - heterochromatin JF - eLife SN - 2050-084X PB - eLife Sciences Publications, Ltd ER -