Cell-Type Specific Profiling of Histone Post-Translational Modifications in the Adult Mouse Striatum

Histone post-translational modifications (hPTMs) regulate gene expression via changes in chromatin accessibility and transcription factor recruitment. At a given locus, the coordinated enrichment of several distinct hPTMs regulate gene expression in response to external stimuli. However, neuronal hPTMs have been primarily characterized in bulk brain tissue and/or tissue pooled across subjects. This obscures both cell-type and individual variability, features essential to understand individual susceptibility to psychiatric disease. To address this limitation, we optimized a hybrid protocol, ICuRuS, to profile both activating and repressive hPTMs in neuronal subtypes from a single mouse. We report here profiling of striatal medium spiny neuron (MSN) subtypes, genetically defined by expression of Adenosine 2a Receptor (A2a) or Dopamine Receptor D1 (D1), which differentially regulate reward processing and pathophysiology. Using ICuRuS, we defined genome-wide, A2a- or D1-specific combinatorial hPTM profiles, and discovered regulatory epigenomic features at genes implicated in neurobiological function and disease.