Abstract
How chromatin folds into mitotic and interphase chromosomes has remained a difficult question for many years. We have used three generations of engineered chromosome regions as a means of visualizing specific chromosome regions in live cells and cells fixed under conditions that preserve large-scale chromatin structure. Our results confirm the existence of large-scale chromatin domains and fibers formed by the folding of 10-nm and 30-nm chromatin fibers into larger, spatially distinct domains. Transcription at levels within severalfold of the levels measured for endogenous loci occur within these large-scale chromatin structures on a condensed template linearly compacted several hundred fold to 1000-fold relative to B-form DNA. However, transcriptional induction is accompanied by a severalfold decondensation of this large-scale chromatin structure that propagates hundreds of kilobases beyond the induced gene. Examination of engineered chromosome regions in mouse embryonic stem cells (ESCs) and differentiated cells suggests a surprising degree of plasticity in this large-scale chromatin structure, allowing long-range DNA interactions within the context of large-scale chromatin fibers. Recapitulation of genespecific differences in large-scale chromatin conformation and nuclear positioning using these engineered chromosome regions will facilitate identification of cis and trans determinants of interphase chromosome architecture.
Original language | English (US) |
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Pages (from-to) | 453-460 |
Number of pages | 8 |
Journal | Cold Spring Harbor symposia on quantitative biology |
Volume | 75 |
DOIs | |
State | Published - 2010 |
ASJC Scopus subject areas
- Biochemistry
- Molecular Biology
- Genetics