Chromatin boundary elements organize genomic architecture and developmental gene regulation in Drosophila Hox clusters

Figure 1 The roles of chromatin boundary elements in organizing genomic and nuclear architecture. Chromatin boundary element (CBE) complexes (brown ovals) may interact with each other (left), nuclear matrix (middle) or nuclear envelope (right) to tether chromatin loops that modulate enhancer-promoter interactions (curved arrows), and block the spread of silent chromatin (grey forbidden circles). Green and orange arrows indicate promoters of hypothetical genes X and Y, respectively. Green and orange boxes, enhancer elements for genes X and Y, respectively.