Figure 1.

3C identifies which loci interact, whereas single-cell imaging reveals the topology of the interaction network. (A) The hypothetical 4C profile of a locus (numbered 4) across a chromosome identifies long-range associations with four other loci. (B) When analysed at the single-cell level, many associations occur in a pairwise manner, and only rarely do multiple loci interact simultaneously. 3C, chromosome conformation capture; 4C, chromosome conformation capture-on-chip or circular chromosome conformation capture.