title: Large-scale chromatin organization of the major histocompatibility complex and other regions of human chromosome 6 and its response to interferon in interphase nuclei.
abstract: The large-scale chromatin organization of the major histocompatibility complex and other regions of chromosome 6 was studied by three-dimensional image analysis in human cell types with major differences in transcriptional activity. Entire gene clusters were visualized by fluorescence in situ hybridization with multiple locus-specific probes. Individual genomic regions showed distinct configurations in relation to the chromosome 6 terrritory. Large chromatin loops containing several megabases of DNA were observed extending outwards from the surface of the domain defined by the specific chromosome 6 paint. The frequency with which a genomic region was observed on an external chromatin loop was cell type dependent and appeared to be related to the number of active genes in that region. Transcriptional up-regulation of genes in the major histocompatibility complex by interferon-gamma led to an increase in the frequency with which this large gene cluster was found on an external chromatin loop. Our data are consistent with an association between large-scale chromatin organization of specific genomic regions and their transcriptional status.
authors.affiliation: Human Cytogenetics Laboratory, Imperial Cancer Research Fund, London WC2A 3PX, UK.
authors.forename: E V
authors.initials: EV
authors.lastname: Volpi
authors.forename: E
authors.initials: E
authors.lastname: Chevret
authors.forename: T
authors.initials: T
authors.lastname: Jones
authors.forename: R
authors.initials: R
authors.lastname: Vatcheva
authors.forename: J
authors.initials: J
authors.lastname: Williamson
authors.forename: S
authors.initials: S
authors.lastname: Beck
authors.forename: R D
authors.initials: RD
authors.lastname: Campbell
authors.forename: M
authors.initials: M
authors.lastname: Goldsworthy
authors.forename: S H
authors.initials: SH
authors.lastname: Powis
authors.forename: J
authors.initials: J
authors.lastname: Ragoussis
authors.forename: J
authors.initials: J
authors.lastname: Trowsdale
authors.forename: D
authors.initials: D
authors.lastname: Sheer
mesh_terms: D002460:Cell Line; D002467:Cell Nucleus / Q000187:drug effects*; D002843:Chromatin / Q000235:genetics*; D002896:Chromosomes, Human, Pair 6; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology*; D007399:Interphase / Q000187:drug effects; D008285:Major Histocompatibility Complex / Q000235:genetics*; D008297:Male; D014158:Transcription, Genetic
chemical_list: D002843:Chromatin; D007371:Interferon-gamma