Radiation-Induced Cytogenetic Damage in Relation to Changes in Interphase Chromosome Conformation

1986 ◽  
Vol 105 (3) ◽  
pp. 341 ◽  
Author(s):  
Gabriel E. Pantelias
2014 ◽  
Vol 2 ◽  
pp. 23-28
Author(s):  
Ye Zhang ◽  
Jimmy Uhlemeyer ◽  
Megumi Hada ◽  
A. Asaithamby ◽  
David J. Chen ◽  
...  

Radiology ◽  
1968 ◽  
Vol 90 (5) ◽  
pp. 958-961
Author(s):  
S. C. Bushong ◽  
J. A. Watson ◽  
N. Wald

2009 ◽  
Vol 185 (1) ◽  
pp. 87-100 ◽  
Author(s):  
Yan Hu ◽  
Igor Kireev ◽  
Matt Plutz ◽  
Nazanin Ashourian ◽  
Andrew S. Belmont

The structure of interphase chromosomes, and in particular the changes in large-scale chromatin structure accompanying transcriptional activation, remain poorly characterized. Here we use light microscopy and in vivo immunogold labeling to directly visualize the interphase chromosome conformation of 1–2 Mbp chromatin domains formed by multi-copy BAC transgenes containing 130–220 kb of genomic DNA surrounding the DHFR, Hsp70, or MT gene loci. We demonstrate near-endogenous transcription levels in the context of large-scale chromatin fibers compacted nonuniformly well above the 30-nm chromatin fiber. An approximately 1.5–3-fold extension of these large-scale chromatin fibers accompanies transcriptional induction and active genes remain mobile. Heat shock–induced Hsp70 transgenes associate with the exterior of nuclear speckles, with Hsp70 transcripts accumulating within the speckle. Live-cell imaging reveals distinct dynamic events, with Hsp70 transgenes associating with adjacent speckles, nucleating new speckles, or moving to preexisting speckles. Our results call for reexamination of classical models of interphase chromosome organization.


2019 ◽  
Author(s):  
Kristin Abramo ◽  
Anne-Laure Valton ◽  
Sergey V. Venev ◽  
Hakan Ozadam ◽  
A. Nicole Fox ◽  
...  

SummaryChromosome folding is extensively modulated as cells progress through the cell cycle. During mitosis, condensin complexes fold chromosomes in helically arranged nested loop arrays. In interphase, the cohesin complex generates loops that can be stalled at CTCF sites leading to positioned loops and topologically associating domains (TADs), while a separate process of compartmentalization drives the spatial segregation of active and inactive chromatin domains. We used synchronized cell cultures to determine how the mitotic chromosome conformation is transformed into the interphase state. Using Hi-C, chromatin binding assays, and immunofluorescence we show that by telophase condensin-mediated loops are lost and a transient folding intermediate devoid of most loops forms. By late telophase, cohesin-mediated CTCF-CTCF loops and positions of TADs start to emerge rapidly. Compartment boundaries are also established in telophase, but long-range compartmentalization is a slow process and proceeds for several hours after cells enter G1. Our results reveal the kinetics and order of events by which the interphase chromosome state is formed and identify telophase as a critical transition between condensin and cohesin driven chromosome folding.


2006 ◽  
Vol 166 (2) ◽  
pp. 319-326 ◽  
Author(s):  
Jan J. W A. Boei ◽  
Janna Fomina ◽  
Firouz Darroudi ◽  
Nico J. D. Nagelkerke ◽  
Leon H. F. Mullenders

2016 ◽  
Author(s):  
Y.A. Eidelman ◽  
S.V. Slanina ◽  
A.V. Aleshchenko ◽  
S.G. Andreev

ABSTRACTThe progress in experimental techniques aimed at 3D genome study is yet to bring about revelation of basic principles of genome folding. Chromosome conformation capture Hi-C technologies provide genome wide mapping of genomic loci interactions but spatial organization of chromosomes remains unknown. Here, we develop a polymer modeling approach to generate the ensemble of 3D chromosome conformations for mapping genetic loci contacts and the positions of megabase chromosomal domains in interphase chromosome at different time of mitosis-interphase transition. We demonstrate that (*) whole chromosome contact map (interactome) generated for mouse chromosome 18 structure and (**) contact patterns, observed soon after mitotic decondensation and remaining similar during G1, correlate well with the experimental Hi-C contact data. The results suggest that contact map formation and spatial compartmentalization of an interphase chromosome are driven by interactions between different types of domains during formation of globular chromosome state at the end of mitotis-G1 transition.


2015 ◽  
Vol 112 (19) ◽  
pp. 6062-6067 ◽  
Author(s):  
Bin Zhang ◽  
Peter G. Wolynes

Chromosome conformation capture experiments provide a rich set of data concerning the spatial organization of the genome. We use these data along with a maximum entropy approach to derive a least-biased effective energy landscape for the chromosome. Simulations of the ensemble of chromosome conformations based on the resulting information theoretic landscape not only accurately reproduce experimental contact probabilities, but also provide a picture of chromosome dynamics and topology. The topology of the simulated chromosomes is probed by computing the distribution of their knot invariants. The simulated chromosome structures are largely free of knots. Topologically associating domains are shown to be crucial for establishing these knotless structures. The simulated chromosome conformations exhibit a tendency to form fibril-like structures like those observed via light microscopy. The topologically associating domains of the interphase chromosome exhibit multistability with varying liquid crystalline ordering that may allow discrete unfolding events and the landscape is locally funneled toward “ideal” chromosome structures that represent hierarchical fibrils of fibrils.


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