Chromatin dynamics is correlated with replication timing

Chromosoma. 2009 Aug;118(4):459-70. doi: 10.1007/s00412-009-0208-6. Epub 2009 Mar 19.

Abstract

Discrete chromatin domains (ChrD), containing an average of approximately 1 Mbp DNA, represent the basic structural units for the regulation of DNA organization and replication in situ. In this study, a bio-computational approach is employed to simultaneously measure the translational motion of large populations of ChrD in the cell nucleus of living cells. Both movement and configurational changes are strikingly higher in early S-phase replicating ChrD compared to those that replicate in mid and late S-phase. The chromatin dynamics was not sensitive to transcription inhibition by alpha-amanitin but was significantly reduced by actinomycin D treatment. Since a majority of active genes replicate in early S-phase, our results suggest a correlation between levels of chromatin dynamics and chromatin poised for active transcription. Analysis of ChrD colocalization with transcription sites and cDNA with ChrD and transcription sites further supports this proposal.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Alpha-Amanitin / pharmacology
  • Carbocyanines / chemistry
  • Cell Nucleus / drug effects
  • Cell Nucleus / genetics
  • Cell Nucleus / metabolism
  • Chromatin / drug effects
  • Chromatin / genetics*
  • Chromatin / metabolism
  • Chromosome Positioning / drug effects
  • DNA Replication / drug effects
  • DNA Replication / genetics*
  • Dactinomycin / pharmacology
  • Deoxyuracil Nucleotides / chemistry
  • Deoxyuracil Nucleotides / metabolism
  • Gene Expression
  • HeLa Cells
  • Humans
  • In Situ Hybridization, Fluorescence
  • Kinetics
  • Microinjections
  • Microscopy, Fluorescence
  • S Phase*
  • Time Factors

Substances

  • Alpha-Amanitin
  • Carbocyanines
  • Chromatin
  • Deoxyuracil Nucleotides
  • cyanine dye 3
  • deoxyuridine triphosphate
  • Dactinomycin