FIGURE 1.

Overview of CTCF and cohesin function. The realms of function of CTCF and cohesin partially overlap, and some of these functions also involve DNA looping. Distinct combinations of these factors and DNA looping are observed at different locations and conditions in cells. Maternally and paternally inherited chromosomes are indicated by appropriate symbols under Imprinting. Although this view is partly speculative, experimental evidence exists for many aspects of CTCF and cohesin function. 3′CBE, 3′-CTCF-binding element; TFs, transcription factors.