The initial description of genomes organization has consisted in the separation between regulatory and protein-coding DNA stretches.
This simple and elegant model has supported the “one region-one function” theory: a genome is a linear arrangement of functional elements interspersed with nonfunctional regions. Recently the advances in transcriptomics technologies have shown that a genomic region can be used for different purposes and that functional elements can co-locate in the same region of the genome.
