Correlation between DNase I hypersensitive site distribution and gene expression in HeLa S3 cells [DNase-Hypersensitivity]

Mapping DNase I hypersensitive sites (DHSs) within nuclear chromatin is a traditional and powerful method of identifying genetic regulatory elements. DHSs have been mapped by capturing the ends of long DNase I-cut fragments (>100,000 bp), or 100-1200 bp DNase I-double cleavage fragments (also called double-hit fragments). But next generation sequencing requires a DNA library containing DNA fragments of 100-500bp. Therefore, we have modified the double-hit method and use short DNA fragments to generate DNA libraries for next generation sequencing. We call this method Short DHS Assay (Short DNAse I Hypersensitive Site assay). The short segments are 100-300bp and can be directly cloned and used for high-throughput sequencing. We identified 83,897 DHSs in 2,343,479 tags across the human genome. Our results indicate that the DHSs identified by the Short DHS assay are consistent with those identified by longer fragments in previous studies. Overall design: HeLa S3 Nuclear extraction and DNase I digestion