The Neuronal Gene Arc Encodes a Repurposed Retrotransposon Gag Protein that Mediates Intercellular RNA TransferElissa D. Pastuzyn & Cameron E. Day & Rachel B. Kearns & Madeleine Kyrke-Smith & Andrew V. Taibi & John McCormick & Nathan Yoder & David M. Belnap & Simon Erlendsson & Dustin R. Morado & John A.G. Briggs & Cédric Feschotte & Jason D. Shepherd2018PDF12 MBEN