Polycomb-mediated chromatin loops revealed by a subkilobase-resolution chromatin interaction map

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 114; no. 33; pp. 8764 - 8769
• Main Authors: Eagen, Kyle P., Aiden, Erez Lieberman, Kornberg, Roger D.
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences 15.08.2017
• Subjects: Biological Sciences; Chromatin; Chromosomes; Crosslinking; CTCF protein; Deoxyribonucleic acid; DNA; DNA sequencing; Drosophila; Loops; Polycomb group proteins; Promoters; gene repression; nuclear architecture; DNA loops; Polycomb; chromosome structure
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.1701291114

The locations of chromatin loops in Drosophila were determined by Hi-C (chemical cross-linking, restriction digestion, ligation, and high-throughput DNA sequencing). Whereas most loop boundaries or “anchors” are associated with CTCF protein in mammals, loop anchors in Drosophila were found most often in association with the polycomb group (PcG) protein Polycomb (Pc), a subunit of polycomb repressive complex 1 (PRC1). Loops were frequently located within domains of PcG-repressed chromatin. Promoters located at PRC1 loop anchors regulate some of the most important developmental genes and are less likely to be expressed than those not at PRC1 loop anchors. Although DNA looping has most commonly been associated with enhancer–promoter communication, our results indicate that loops are also associated with gene repression.