GSE43499
Genome-wide analysis of histone modifications H3K4me3, H3K4me1, and H3K27ac in primary human corneal epithelial cells
The corneal epithelium is a stratified squamous epithelium that protects the eye from mechanical and toxic stress. In this system, cells are continually being sloughed off from the surface of the eye, and replenished by proliferation from corneal stem cells in the limbus, which migrate in and differentiate. During tissue development and homeostasis, distal regulatory regions called enhancers, which contain binding sites for numerous transcription factors, help to control and coordinate gene expression in a temporal and spatial specific manner. To identify enhancers in cornea epithelia, we performed ChIP-Seq with antibodies to the histone marks H3K4me3, H3K4me1, and H3K27ac in primary human corneal epithelial cells. Active enhancers were defined as having high levels of H3K4me1 and H3K27ac, and low levels of H3K4me3: 12,900 such regions were identified in the corneal epithelial cells. In combination with primary cell histone modification ChIP-Seq data from BROAD, 2946 active enhancer regions were identified that are unique to the corneal epithelial cells: 1551 of theses 2946 also overlie regions of high evolutionary constraint. Motif enrichment analysis of these regions has revealed binding sites for a number of transcription factors, highlighting their roles as key regulators of corneal epithelial development. Overall design: ChIP experiments for histone modifications H3K4me1, H3K4me3, and H3K27ac were performed on primary human corneal epithelial cells, and were sequenced on the Hi-Seq 2000.