title: Remembering silence.
abstract: Polycomb response elements (PREs) are regulatory switch elements that can direct the genes that they control to be either active or silenced. Once decided, this on or off state is maintained through subsequent cell divisions. We do not know how the switching works, or how it is copied to newly replicated chromosomes. Experiments that switch a silenced PRE to an active state have provided insights into both questions. A PRE switched experimentally can remember its previously silenced state and return to it after several cell divisions. In the most recent study of this phenomen on, the data show that several distinct variables affect the ability of PREs to "remember" and restore their previous state. The authors' interpretation of these results is discussed here.
authors.affiliation: University of Heidelberg, Germany.
authors.forename: L
authors.initials: L
authors.lastname: Ringrose
authors.forename: R
authors.initials: R
authors.lastname: Paro
mesh_terms: D000818:Animals; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000235:genetics*; D005786:Gene Expression Regulation; D020868:Gene Silencing; D017344:Genes, Insect; D019476:Insect Proteins / Q000235:genetics*; D063150:Polycomb Repressive Complex 1; D020218:Response Elements
chemical_list: D029721:Drosophila Proteins; D019476:Insect Proteins; C066770:Pc protein, Drosophila; D063150:Polycomb Repressive Complex 1