Histone modifications in activated and freshly isolated mouse muscle stem cells by ChIP-seq

Regulation of chromatin accessibility is critical for cell fate decisions. Chromatin architecture responds to extrinsic environments rapidly. The traditional adult stem cell isolation approach requires tissue dissociation, and adult stem cells respond to the stimulation and adapt a different chromatin conformation. Here, we characterized the DNA regulatory landscape and transcriptomic profile of muscle stem cell quiescence exit and self-renewal by time-course profiling of the in situ fixed SCs upon injury-induced activation and during aging. Detailed analysis of the chromatin accessibility profiles leads to the identification of enhancer elements for SC quiescence. Constant activation of the enhancer elements promotes stemness and prevents SCs from differentiation, whereas loss of them causes cell-cycle arrest and essentially leads to defects in SC activation. Interestingly, we also showed that aged SCs display a more open chromatin environment than young SCs. Our compre hensive characterization of the chromatin accessibility and transcriptomic landscapes during SC quiescence exit and self-renewal broadens our understanding of this process and identifies functional distal regulatory elements for SC function. We report the application of ChIPmentation on examination of H3K27ac histone marks in freshly isolated satellite cells (FISC) and activated satellite cells isolated after 2.5 days post-injury (ASC). We observed increase of H3K27ac marks around transcription start sites (TSS) and distinct peak patterns in distal intergenic regions during satellite cell activation. Examination of H3K27ac marks in FISC and ASC.