title: A genome-wide analysis of open chromatin in human epididymis epithelial cells reveals candidate regulatory elements for genes coordinating epididymal function.
abstract: The epithelium lining the epididymis has a pivotal role in ensuring a luminal environment that can support normal sperm maturation. Many of the individual genes that encode proteins involved in establishing the epididymal luminal fluid are well characterized. They include ion channels, ion exchangers, transporters, and solute carriers. However, the molecular mechanisms that coordinate expression of these genes and modulate their activities in response to biological stimuli are less well understood. To identify cis-regulatory elements for genes expressed in human epididymis epithelial cells, we generated genome-wide maps of open chromatin by DNase-seq. This analysis identified 33,542 epididymis-selective DNase I hypersensitive sites (DHS), which were not evident in five cell types of different lineages. Identification of genes with epididymis-selective DHS at their promoters revealed gene pathways that are active in immature epididymis epithelial cells. These include processes correlating with epithelial function and also others with specific roles in the epididymis, including retinol metabolism and ascorbate and aldarate metabolism. Peaks of epididymis-selective chromatin were seen in the androgen receptor gene and the cystic fibrosis transmembrane conductance regulator (CFTR) gene, which has a critical role in regulating ion transport across the epididymis epithelium. In silico prediction of transcription factor binding sites that were overrepresented in epididymis-selective DHS identified epithelial transcription factors, including ELF5 and ELF3, the androgen receptor, Pax2, and Sox9, as components of epididymis transcriptional networks. Active genes, which are targets of each transcription factor, reveal important biological processes in the epididymis epithelium.
authors.affiliation: Human Molecular Genetics Program, Lurie Children's Research Center, and Department of Pediatrics, Northwestern University Feinberg School of Medicine Chicago, Illinois.
authors.forename: Jared M
authors.initials: JM
authors.lastname: Bischof
authors.forename: Austin E
authors.initials: AE
authors.lastname: Gillen
authors.forename: Lingyun
authors.initials: L
authors.lastname: Song
authors.forename: Nehal
authors.initials: N
authors.lastname: Gosalia
authors.forename: Darin
authors.initials: D
authors.lastname: London
authors.forename: Terrence S
authors.initials: TS
authors.lastname: Furey
authors.forename: Gregory E
authors.initials: GE
authors.lastname: Crawford
authors.forename: Ann
authors.initials: A
authors.lastname: Harris
mesh_terms: D002478:Cells, Cultured; D042002:Chromatin Assembly and Disassembly; D002874:Chromosome Mapping; D019295:Computational Biology; D021901:DNA, Intergenic; D004822:Epididymis / Q000166:cytology / Q000254:growth & development / Q000378:metabolism* / Q000503:physiopathology; D004847:Epithelial Cells / Q000166:cytology / Q000378:metabolism*; D005103:Expert Systems; D005333:Fetus / Q000166:cytology; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D055106:Genome-Wide Association Study; D006801:Humans; D007248:Infertility, Male / Q000235:genetics* / Q000378:metabolism / Q000503:physiopathology; D008297:Male; D009707:Nucleosomes / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis; D009928:Organ Specificity; D011401:Promoter Regions, Genetic; D013091:Spermatogenesis
chemical_list: D021901:DNA, Intergenic; D009707:Nucleosomes
keywords: epididymis epithelium; male infertility; sperm maturation; transcriptional regulation