Genome-wide approaches to determining nucleosome occupancy in metazoans using MNase-Seq.

The precise location of nucleosomes in functional regulatory regions in chromatin is critical to the regulation of transcription. The nucleosome structure protects DNA from microccocal nuclease (MNase) digestion and leaves a footprint on DNA that indicates the position of nucleosomes. Short sequence reads (25-36 bp) from ends of mononucleosome-sized DNA generated from MNase digestion of chromatin can be determined using next-generation sequencing techniques. Mapping of these short reads to the genome provides a powerful genome-wide approach to precisely define the nucleosome positions in any genome with known genomic sequence. This chapter outlines the reagents and experimental procedures of MNase-Seq for mapping nucleosome positions in the human genome.