The Schorn lab is interested in mechanisms of small RNA-mediated transposon control, which enabled domestication of transposon sequences for gene regulatory networks and heterochromatin formation, while restricting mutagenic mobility of transposons during epigenetic reprogramming. We found that tRNA fragments (tRF) derived from the 3′-end of mature tRNAs are highly expressed in cells undergoing epigenetic reprogramming and specifically inhibit long terminal repeat (LTR)-retrotransposons and -retroviruses at their highly conserved tRNA primer binding site. These 3′-tRFs are processed from full-length tRNAs under yet unknown conditions and potentially protect many cell types in eukaryotes. They act as an ancient link between RNA interference, transposons and genome stability, with potential roles in epigenetic inheritance and cancer.
Andrea Schorn has a longstanding interest and training in host-pathogen interactions and repetitive sequences in genome regulation, beginning with her undergraduate research at the Virology department, University of Zürich, and the Max-Planck Institute for Infection Biology, Berlin, and continuing during her PhD at the Max-Delbrück Center for Molecular Medicine Berlin. As a postdoctoral fellow at Cold Spring Harbor Laboratory (CSHL), she set out to identify small RNAs that guide genome integrity during epigenetic reprogramming in the early mouse embryo, which resulted in her findings on transposon control by 3′-tRFs. Early 2019, Dr. Schorn started her own independent lab at CSHL, where her group investigates key epigenetic determinants and RNA-binding proteins of this novel small RNA silencing mechanism.