Constricting restricted transcription: the (actively?) shrinking web

摘要

It is now quite generally accepted that the mammalian genome is, in essence, littered with functionally critical regulatory elements that can be located anywhere in relationship to the gene that they control: internally, 5' or 3', sometimes even more than a megabase away (Lettice et al. 2002). Furthermore, seemingly straightforward activities of a gene can be controlled by multiple spatially or temporally distinct enhancers, even for eliciting, in a single developing tissue, functions that never could have been identified as distinct by conventional methods (Khandekar et al. 2004)