show Abstracthide AbstractWe report a vital role for H2Bubi in active and repressive gene transcription during long-term memory formation. We found that fear conditioning increased or decreased the expression of 86 genes in the hippocampus one hour after training. Remarkably, siRNA knockdown of the H2Bubi ligase, Rnf20, abolished changes in all but one of these genes, Per1, suggesting a critical role for the H2Bubi epigenetic mark in active and repressive gene transcription during memory consolidation. Overall design: Male Sprague-Dawley rats were injected into the dorsal hippocampus CA1 region with Accell siRNA against Rnf20 or control (Scr-siRNA). Five days later animals were trained to contextual fear conditioning and the CA1 region (dorsal) was dissected, RNA collected via columns and used for RNA-seq analysis