EpiDiff: entropy-based quantitative identification of differential epigenetic modification regions from epigenomes.

Genome-wide epigenetic modification dynamics, including DNA methylation and chromatin modification, are involved in biological processes such as development, aging, and disease. Quantitative identification of differential epigenetic modification regions (DEMRs) from various temporal and spatial epigenomes is a crucial step towards investigating the relationship between epigenotype and phenotype. Here, we describe EpiDiff (http://bioinfo.hrbmu.edu.cn/epidiff/), an integrated software platform that supports quantification of epigenetic difference and identification of DEMRs by Shannon entropy. Two main modules, quantitative differential chromatin modification region (QDCMR) and quantitative differentially methylated region (QDMR) are provided for bioinformatic analysis of chromatin modifications and DNA methylation data, respectively. The third module, quantitative differential expressed gene (QDEG), can be used to identify differentially expressed genes. The platform-free and species-free nature of EpiDiff makes it potentially applicable to a wide variety of epigenomes at an unprecedented scale and resolution. The graphical user interface provides biologists with a practicable and reliable way to analyze and visualize epigenetic difference.