Targeted DamID detects cell-type specific histone modificationsin vivo

Abstract

AbstractHistone modifications play a key role in regulating gene expression and cell fate during development and disease. Current methods for cell-type specific genome-wide profiling of histone modifications require dissociation and isolation of cells and are not compatible with all tissue types. Here we adapt Targeted DamID to recognise specific histone marks, by fusing chromatin binding proteins or single-chain antibodies to Dam, anE. coliDNA adenine methylase. When combined with Targeted DamID (TaDa), this enables cell-type specific chromatin profiling in intact tissues or organisms. We first profiled H3K4me3, H3K9ac, H3K27me3 and H4K20me1in vivoin neural stem cells of the developingDrosophilabrain. Next, we mapped cell-type specific H3K4me3 distribution in neural stem cells of the developing mouse brain. Finally, we injected RNA encoding DamID constructs into 1-cell stageXenopusembryos to profile H3K4me3 distribution during gastrulation and neurulation. These results illustrate the versatility of Targeted DamID to profile cell-type specific histone marks throughout the genome in diverse model systems.Summary statementTargeted DamID enables genome-wide cell-type specific detection of histone modificationsin vivoinDrosophila, mouse andXenopus.