This Article Full Text Full Text (PDF) All Versions of this Article: biophysj.105.066670v1 89/6/4275    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Levi, V. Articles by Gratton, E. Search for Related Content PubMed PubMed Citation Articles by Levi, V. Articles by Gratton, E.

Chromatin Dynamics in Interphase Cells Revealed by Tracking in a Two-Photon Excitation Microscope

Valeria Levi ^*, QiaoQiao Ruan ^*, Matthew Plutz , Andrew S. Belmont  and Enrico Gratton ^*

^* Laboratory for Fluorescence Dynamics, and Department of Cell and Structural Biology, Chemical and Life Science Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois

Correspondence: Address reprint requests to Enrico Gratton, Laboratory for Fluorescence Dynamics, University of Illinois at Urbana-Champaign, 1110 West Green St., Urbana, IL 61801-3080. Tel.: 217-244-5620; Fax: 217-244-7187; E-mail: enrico{at}scs.uiuc.edu.

Increasing evidence points to a dynamical compartmentalization of the cell nucleus, yet the mechanisms by which interphase chromatin moves and is positioned within nuclei remain unclear. Here, we study the dynamics of chromatin in vivo applying a novel particle-tracking method in a two-photon microscope that provides 10-fold higher spatial and temporal resolutions than previous measurements. We followed the motion of a chromatin sequence containing a lac-operator repeat in cells stably expressing lac repressor fused with enhanced green fluorescent protein, observing long periods of apparent constrained diffusion interrupted by relatively abrupt jumps of 150 nm lasting 0.3–2 s. During these jumps, the particle moved an average of four times faster than in the periods between jumps and in paths more rectilinear than predicted for random diffusion motion. Additionally, the jumps were sensitive to the temperature and absent after ATP depletion. These experimental results point to an energy-dependent mechanism driving fast motion of chromatin in interphase cells.

This article has been cited by other articles:

				G. N. Corry, M. J. Hendzel, and D. A. Underhill Subnuclear localization and mobility are key indicators of PAX3 dysfunction in Waardenburg syndrome Hum. Mol. Genet., June 15, 2008; 17(12): 1825 - 1837. [Abstract] [Full Text] [PDF]

				M. J. Saxton A Biological Interpretation of Transient Anomalous Subdiffusion. I. Qualitative Model Biophys. J., February 15, 2007; 92(4): 1178 - 1191. [Abstract] [Full Text] [PDF]

				B. Banerjee, D. Bhattacharya, and G.V. Shivashankar Chromatin Structure Exhibits Spatio-Temporal Heterogeneity within the Cell Nucleus Biophys. J., September 15, 2006; 91(6): 2297 - 2303. [Abstract] [Full Text] [PDF]