Figure 1. Long-range interactions in the IRX3/FTO locus.

a, Mouse embryo 4C-seq interactions emanating from each promoter are displayed as links across the circle (darker link implies greater significance). Outer plots show significance of interactions above background (-log(p-value)). The obesity-associated interval is highlighted red. b, Magnified view of the association interval. Contained within are the orthologous locations of obesity-associated SNPs (black pips), and epigenetic marks associated with regulatory elements. Endogenous Irx3 expression is shown (1. lung, 2. brain) in Irx3^lacZ knockin mouse. Three enhancers (rectangles 3–5) drive reporter expression in lungs (3, 5) and brain (4). Other enhancers¹⁷ are shown in black.