title: Making connections: insulators organize eukaryotic chromosomes into independent cis-regulatory networks.
abstract: Insulators play a central role in subdividing the chromosome into a series of discrete topologically independent domains and in ensuring that enhancers and silencers contact their appropriate target genes. In this review we first discuss the general characteristics of insulator elements and their associated protein factors. A growing collection of insulator proteins have been identified including a family of proteins whose expression is developmentally regulated. We next consider several unexpected discoveries that require us to completely rethink how insulators function (and how they can best be assayed). These discoveries also require a reevaluation of how insulators might restrict or orchestrate (by preventing or promoting) interactions between regulatory elements and their target genes. We conclude by connecting these new insights into the mechanisms of insulator action to dynamic changes in the three-dimensional topology of the chromatin fiber and the generation of specific patterns of gene activity during development and differentiation.
authors.affiliation: Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia.
authors.forename: Darya
authors.initials: D
authors.lastname: Chetverina
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Aoki
authors.forename: Maksim
authors.initials: M
authors.lastname: Erokhin
authors.forename: Pavel
authors.initials: P
authors.lastname: Georgiev
authors.forename: Paul
authors.initials: P
authors.lastname: Schedl
mesh_terms: D002875:Chromosomes / Q000235:genetics*; D005786:Gene Expression Regulation / Q000235:genetics; D038101:Insulator Elements / Q000235:genetics*; D008954:Models, Biological
keywords: bithorax complex; boundary elements; chromosomal domains; developmental regulation; insulator bypass; insulators; non-autonomy