title: Mechanism of chromosomal boundary action: roadblock, sink, or loop?
abstract: Boundary elements or insulators subdivide eukaryotic chromosomes into a series of structurally and functionally autonomous domains. They ensure that the action of enhancers and silencers is restricted to the domain in which these regulatory elements reside. Three models, the roadblock, sink/decoy, and topological loop, have been proposed to explain the insulating activity of boundary elements. Strong predictions about how boundaries will function in different experimental contexts can be drawn from these models. In the studies reported here, we have designed assays that test these predictions. The results of our assays are inconsistent with the expectations of the roadblock and sink models. Instead, they support the topological loop model.
authors.affiliation: Department of Molecular Biology, Princeton University, Princeton, New Jersey 08540, USA.
authors.forename: Daryl
authors.initials: D
authors.lastname: Gohl
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Aoki
authors.forename: Jason
authors.initials: J
authors.lastname: Blanton
authors.forename: Greg
authors.initials: G
authors.lastname: Shanower
authors.forename: Gretchen
authors.initials: G
authors.lastname: Kappes
authors.forename: Paul
authors.initials: P
authors.lastname: Schedl
mesh_terms: D000818:Animals; D002875:Chromosomes / Q000235:genetics*; D004331:Drosophila melanogaster / Q000235:genetics*; D038101:Insulator Elements / Q000235:genetics*; D010641:Phenotype; D050436:Regulatory Elements, Transcriptional / Q000235:genetics*; D037941:Silencer Elements, Transcriptional / Q000235:genetics*