Functional maps of a genomic locus reveal confinement of an enhancer by its target gene

Abstract

AbstractGenes are often activated by enhancers located at large genomic distances. The importance of this positioning is poorly understood. By relocating promoter-reporter constructs into >1,000 alternative positions within a single locus, we dissected the positional relationship between the mouseSox2gene and its distal enhancer. This revealed an intricate, sharply confined activation landscape, in which the nativeSox2gene occupies an optimal position for its activation. Deletion of the gene relaxes this confinement and broadly increases reporter activity. Surprisingly, the confining effect of theSox2gene is partially conferred by its ∼1 kb coding region. Our local relocation approach provides high-resolution functional maps of a genomic locus and reveals that a gene can strongly constrain the realm of influence of its enhancer.