Mapping chromosome neighborhoods
Eukaryotic genes don’t generally act alone. Their expression typically is driven by interactions with proximal promoters, promoters who are themselves influenced by the concerted action of distal enhancer and repressor sequences often located hundreds of kilobases away. In short, eukaryotic gene expression is a complex and intricate business. Cartoons and diagrams usually portray these interactions as simple loops, with transcription factors binding to regulatory sequences, acting as bridges to tweak the activity of distant gene promoters. Yet it’s clear that in reality, the nucleus must be loaded with such loops: Mammalian genomes, notes Job Dekker, Professor and Co-director of the Program in Systems Biology at the University of Massachusetts Medical School, are chock full of regulatory sequences, some constitutive, others transmitting subtle developmental cues. Given the genetic cacophony this situation can produce, how can cells limit genetic “distractions” to ensure regulatory sequences act only where they’re supposed to? Read more at BioTechniques. (PDF)
Biotechnically Speaking 