title: RNA as a fundamental component of interphase chromosomes: could repeats prove key?
abstract: Beginning with the precedent of XIST RNA as a 'chromosomal RNA' (cRNA), there is growing interest in the possibility that a diversity of non-coding RNAs may function in chromatin. We review findings which lead us to suggest that RNA is essentially a widespread component of interphase chromosomes. Further, RNA likely contributes to architecture and regulation, with repeat-rich 'junk' RNA in euchromatin (ecRNA) promoting a more open chromatin state. Thousands of low-abundance nuclear RNAs have been reported, however it remains a challenge to determine which of these may function in chromatin. Recent findings indicate that repetitive sequences are enriched in chromosome-associated non-coding RNAs, and repeat-rich RNA shows unusual properties, including localization and stability, with similarities to XIST RNA. We suggest two frontiers in genome biology are emerging and may intersect: the broad contribution of RNA to interphase chromosomes and the distinctive properties of repeat-rich intronic or intergenic junk sequences that may play a role in chromosome structure and regulation.
authors.affiliation: Department of Cell & Developmental Biology, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, MA 01655, USA.
authors.forename: Lisa L
authors.initials: LL
authors.lastname: Hall
authors.affiliation: Department of Cell & Developmental Biology, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, MA 01655, USA. Electronic address: Jeanne.Lawrence@umassmed.edu.
authors.forename: Jeanne B
authors.initials: JB
authors.lastname: Lawrence
mesh_terms: D001483:Base Sequence / Q000235:genetics; D002843:Chromatin / Q000235:genetics*; D002875:Chromosomes / Q000235:genetics*; D022041:Euchromatin / Q000235:genetics; D016678:Genome; D007399:Interphase / Q000235:genetics*; D012313:RNA / Q000235:genetics*; D062085:RNA, Long Noncoding / Q000235:genetics
chemical_list: D002843:Chromatin; D022041:Euchromatin; D062085:RNA, Long Noncoding; C077885:XIST non-coding RNA; D012313:RNA