Large-scale chromatin organization of the major histocompatibility complex and other regions of human chromosome 6 and its response to interferon in interphase nuclei.
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.
Volpi
E V
EV
Human Cytogenetics Laboratory, Imperial Cancer Research Fund, London WC2A 3PX, UK.
Chevret
E
E
Jones
T
T
Vatcheva
R
R
Williamson
J
J
Beck
S
S
Campbell
R D
RD
Goldsworthy
M
M
Powis
S H
SH
Ragoussis
J
J
Trowsdale
J
J
Sheer
D
D
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
D002843:Chromatin; D007371:Interferon-gamma