High-throughput chromatin motion tracking in living yeast reveals the flexibility of the fiber throughout the genome
- Houssam Hajjoul1,2,6,
- Julien Mathon1,2,6,
- Hubert Ranchon1,2,
- Isabelle Goiffon2,3,
- Julien Mozziconacci4,5,
- Benjamin Albert2,3,
- Pascal Carrivain4,5,
- Jean-Marc Victor4,5,
- Olivier Gadal2,3,
- Kerstin Bystricky2,3 and
- Aurélien Bancaud1,2,7
- 1LAAS, CNRS, F-31400 Toulouse, France;
- 2University of Toulouse, F-31062 Toulouse, France;
- 3LBME, CNRS, F-31000 Toulouse, France;
- 4LPTMC UMR 7600, CNRS, University Pierre et Marie Curie-Paris 6, 75252 Paris Cedex 05, France;
- 5CNRS GDR 3536, University Pierre et Marie Curie-Paris 6, 75252 Paris Cedex 05, France
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↵6 These authors contributed equally to this work.
Abstract
Chromosome dynamics are recognized to be intimately linked to genomic transactions, yet the physical principles governing spatial fluctuations of chromatin are still a matter of debate. Using high-throughput single-particle tracking, we recorded the movements of nine fluorescently labeled chromosome loci located on chromosomes III, IV, XII, and XIV of Saccharomyces cerevisiae over an extended temporal range spanning more than four orders of magnitude (10−2–103 sec). Spatial fluctuations appear to be characterized by an anomalous diffusive behavior, which is homogeneous in the time domain, for all sites analyzed. We show that this response is consistent with the Rouse polymer model, and we confirm the relevance of the model with Brownian dynamics simulations and the analysis of the statistical properties of the trajectories. Moreover, the analysis of the amplitude of fluctuations by the Rouse model shows that yeast chromatin is highly flexible, its persistence length being qualitatively estimated to <30 nm. Finally, we show that the Rouse model is also relevant to analyze chromosome motion in mutant cells depleted of proteins that bind to or assemble chromatin, and suggest that it provides a consistent framework to study chromatin dynamics. We discuss the implications of our findings for yeast genome architecture and for target search mechanisms in the nucleus.
Footnotes
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↵7 Corresponding author
E-mail abancaud{at}laas.fr
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[Supplemental material is available for this article.]
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Article published online before print. Article, supplemental material, and publication date are at http://www.genome.org/cgi/doi/10.1101/gr.157008.113.
- Received February 28, 2013.
- Accepted July 3, 2013.
This article is distributed exclusively by Cold Spring Harbor Laboratory Press for the first six months after the full-issue publication date (see http://genome.cshlp.org/site/misc/terms.xhtml). After six months, it is available under a Creative Commons License (Attribution-NonCommercial 3.0 Unported), as described at http://creativecommons.org/licenses/by-nc/3.0/.