Project description:Non-coding variants coordinate transcription factor (TF) binding and chromatin mark enrichment changes over regions spanning >100 kb. We named these molecularly coordinated regions “variable chromatin modules” (VCMs), providing a conceptual framework of how regulatory variation might shape complex traits. To better understand the molecular mechanisms underlying VCM formation, here, we mechanistically dissect an uncharacterized VCM-modulating non-coding variant that is associated with reduced chronic lymphocytic leukemia (CLL) predisposition and disease progression. This common, germline variant constitutes a 5-bp indel that controls the activity of an AXIN2 gene-linked VCM by creating a MEF2 binding site, which, upon binding, activates a super-enhancer-like regulatory element. This triggers a big change in TF binding activity and chromatin state at an enhancer cluster spanning >150 kb, coinciding with long-range chromatin compaction and AXIN2 up-regulation. Our results support a model in which the indel acts as an AXIN2 VCM-activating TF nucleation event, which modulates CLL pathology.
Project description:We identified 6,975 insertion/deletion events of between 10 and 100 bp in length from the Drosophila simulans and Drosophila sechellia Mercator/MAVID genomic sequence alignment. Replicate pure samples of Drosophila simulans and Drosophila sechellia gDNA were competitively hybridized to measure the expected relative hybridization intensity of alleles from each species. We used these measured intensities to assess the likelihood that the hybridization signal at each probe in an experimental animal reflected homozygosity or heterozygosity at that locus. Indel array Agilent-022089 sim-sech.v.1.3