title: A gene loop containing the floral repressor FLC is disrupted in the early phase of vernalization.
abstract: Gene activation in eukaryotes frequently involves interactions between chromosomal regions. We have investigated whether higher-order chromatin structures are involved in the regulation of the Arabidopsis floral repressor gene FLC, a target of several chromatin regulatory pathways. Here, we identify a gene loop involving the physical interaction of the 5' and 3' flanking regions of the FLC locus using chromosome conformation capture. The FLC loop is unaffected by mutations disrupting conserved chromatin regulatory pathways leading to very different expression states. However, the loop is disrupted during vernalization, the cold-induced, Polycomb-dependent epigenetic silencing of FLC. Loop disruption parallels timing of the cold-induced FLC transcriptional shut-down and upregulation of FLC antisense transcripts, but does not need a cold-induced PHD protein required for the epigenetic silencing. We suggest that gene loop disruption is an early step in the switch from an expressed to a Polycomb-silenced state.
authors.affiliation: Department of Cell and Developmental Biology, John Innes Centre, Norwich, UK.
authors.forename: Pedro
authors.initials: P
authors.lastname: Crevillén
authors.forename: Cagla
authors.initials: C
authors.lastname: Sonmez
authors.forename: Zhe
authors.initials: Z
authors.lastname: Wu
authors.forename: Caroline
authors.initials: C
authors.lastname: Dean
mesh_terms: D024509:3' Flanking Region / Q000235:genetics; D024506:5' Flanking Region / Q000235:genetics; D000064:Acclimatization / Q000235:genetics; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D002843:Chromatin / Q000235:genetics*; D003080:Cold Temperature; D015536:Down-Regulation; D044127:Epigenesis, Genetic; D035264:Flowers / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D018506:Gene Expression Regulation, Plant; D020868:Gene Silencing; D026161:MADS Domain Proteins / Q000235:genetics* / Q000378:metabolism; D009154:Mutation; D063146:Polycomb-Group Proteins / Q000235:genetics* / Q000378:metabolism; D016372:RNA, Antisense / Q000235:genetics; D018749:RNA, Plant / Q000235:genetics; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism; D036226:Seedlings; D015533:Transcriptional Activation / Q000235:genetics; D015854:Up-Regulation
chemical_list: D029681:Arabidopsis Proteins; D002843:Chromatin; C418902:At5g10140 protein, Arabidopsis; D026161:MADS Domain Proteins; D063146:Polycomb-Group Proteins; D016372:RNA, Antisense; D018749:RNA, Plant; D012097:Repressor Proteins