title: RNAi components are required for nuclear clustering of Polycomb group response elements.
abstract: Drosophila Polycomb group (PcG) proteins silence homeotic genes through binding to Polycomb group response elements (PREs). Fab-7 is a PRE-containing regulatory element from the homeotic gene Abdominal-B. When present in multiple copies in the genome, Fab-7 can induce long-distance gene contacts that enhance PcG-dependent silencing. We show here that components of the RNA interference (RNAi) machinery are involved in PcG-mediated silencing at Fab-7 and in the production of small RNAs at transgenic Fab-7 copies. In general, these mutations do not affect the recruitment of PcG components, but they are specifically required for the maintenance of long-range contacts between Fab-7 copies. Dicer-2, PIWI, and Argonaute1, three RNAi components, frequently colocalize with PcG bodies, and their mutation significantly reduces the frequency of PcG-dependent chromosomal associations of endogenous homeotic genes. This suggests a novel role for the RNAi machinery in regulating the nuclear organization of PcG chromatin targets.
authors.affiliation: Institute of Human Genetics, CNRS, 141 rue de la Cardonille, 34396 Montpellier Cedex 5, France.
authors.forename: Charlotte
authors.initials: C
authors.lastname: Grimaud
authors.forename: Frédéric
authors.initials: F
authors.lastname: Bantignies
authors.forename: Manika
authors.initials: M
authors.lastname: Pal-Bhadra
authors.forename: Pallavi
authors.initials: P
authors.lastname: Ghana
authors.forename: Utpal
authors.initials: U
authors.lastname: Bhadra
authors.forename: Giacomo
authors.initials: G
authors.lastname: Cavalli
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D002467:Cell Nucleus / Q000378:metabolism*; D002875:Chromosomes / Q000378:metabolism; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D020868:Gene Silencing; D017404:In Situ Hybridization, Fluorescence; D007814:Larva / Q000033:anatomy & histology / Q000502:physiology; D009154:Mutation; D010641:Phenotype; D063150:Polycomb Repressive Complex 1; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D020218:Response Elements
chemical_list: D029721:Drosophila Proteins; C066770:Pc protein, Drosophila; D034741:RNA, Small Interfering; D012097:Repressor Proteins; D063150:Polycomb Repressive Complex 1