Fig. 3

The nucleus has areas of chromosome territories (colored clouds) and regions that are open containing RNA polymerases (central orange cloud). A specific set of transcription figures creates an enhanceosome which binds to a specific enhancer. It also binds to a realisator gene which is on its own loop divided into introns and exons. If the gene and enhancer is open, as in realisator loop 1, the DNA can be bound to the enhanceosome if the correct transcription factors are present and form a regulatory archipelago. The gene is then transcribed. If the DNA is sequestered, as in Realisator Loops 2, the DNA cannot be bound the enhanceosome even if the correct transcription factors are present. If the DNA is condensed (as in Realisator Loops 3 and 4 and their enhancers) it completely inaccessible