| Autor: |
Allahyar, Amin, Vermeulen, Carlo, Bouwman, Britta A.M., Krijger, Peter H.L., Verstegen, Marjon J.A.M., Geeven, Geert, Kranenburg, Melissa van, Pieterse, Mark, Straver, Roy, Haarhuis, Judith H.I., Teunissen, Hans, Renkens, Ivo J., Kloosterman, Wigard P., Rowland, Benjamin D., de Wit, Elzo, de Ridder, Jeroen, de Laat, Wouter |
| Rok vydání: |
2017 |
| Popis: |
Chromatin folding is increasingly recognized as a regulator of genomic processes such as gene activity. Chromosome conformation capture (3C) methods have been developed to unravel genome topology through the analysis of pair-wise chromatin contacts and have identified many genes and regulatory sequences that, in populations of cells, are engaged in multiple DNA interactions. However, pair-wise methods cannot discern whether contacts occur simultaneously or in competition on the individual chromosome. We present a novel 3C method, Multi-Contact 4C (MC-4C), that applies Nanopore sequencing to study multi-way DNA conformations of tens of thousands individual alleles for distinction between cooperative, random and competing interactions. MC-4C can uncover previously missed structures in sub-populations of cells. It reveals unanticipated cooperative clustering between regulatory chromatin loops, anchored by enhancers and gene promoters, and CTCF and cohesin-bound architectural loops. For example, we show that the constituents of the active b-globin super-enhancer cooperatively form an enhancer hub that can host two genes at a time. We also find cooperative interactions between further dispersed regulatory sequences of the active proto-cadherin locus. When applied to CTCF-bound domain boundaries, we find evidence that chromatin loops can collide, a process that is negatively regulated by the cohesin release factor WAPL. Loop collision is further pronounced in WAPL knockout cells, suggestive of a “cohesin traffic jam”. In summary, single molecule multi-contact analysis methods can reveal how the myriad of regulatory sequences spatially coordinate their actions on individual chromosomes. Insight into these single allele higher-order topological features will facilitate interpreting the consequences of natural and induced genetic variation and help uncovering the mechanisms shaping our genome. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
|
