@article {Berkyurek2020.05.01.070433, author = {Ahmet C. Berkyurek and Giulia Furlan and Lisa Lampersberger and Toni Beltran and Eva-Maria Weick and Emily Nischwitz and Isabela Cunha Navarro and Fabian Braukmann and Alper Akay and Jonathan Price and Falk Butter and Peter Sarkies and Eric A. Miska}, title = {The RNA Polymerase II core subunit RPB-9 directs transcriptional elongation at piRNA loci in Caenorhabditis elegans}, elocation-id = {2020.05.01.070433}, year = {2020}, doi = {10.1101/2020.05.01.070433}, publisher = {Cold Spring Harbor Laboratory}, abstract = {PIWI-interacting RNAs (piRNAs) are genome-encoded small RNAs that regulate germ cell development and maintain germline integrity in many animals. Mature piRNAs engage Piwi Argonaute proteins to silence complementary transcripts, including transposable elements and endogenous genes. piRNA biogenesis mechanisms are diverse and remain poorly understood. Here, we identify the RNA Polymerase II (RNA Pol II) core subunit RPB-9 as required for piRNA-mediated silencing in the nematode Caenorhabditis elegans. rpb-9 mutants fail to initiate heritable piRNA-mediated gene silencing. Furthermore, we show that RPB-9 is required to repress two DNA transposon families and a subset of somatic genes in the C. elegans germline. We provide genetic and biochemical evidence that RPB-9 is required for piRNA biogenesis. We demonstrate that RPB-9 acts to promote transcriptional elongation/termination at endogenous piRNA loci. We conclude that as a part of its rapid evolution the piRNA pathway has co-opted another ancient machinery, this time for high-fidelity transcription.Competing Interest StatementThe authors have declared no competing interest.}, URL = {https://www.biorxiv.org/content/early/2020/05/01/2020.05.01.070433}, eprint = {https://www.biorxiv.org/content/early/2020/05/01/2020.05.01.070433.full.pdf}, journal = {bioRxiv} }