Examining how the spatial organization of chromatin signals influences metaphase spindle assembly

Nat Cell Biol. 2006 Sep;8(9):924-32. doi: 10.1038/ncb1455. Epub 2006 Aug 6.


During cell division, the proper assembly of a microtubule-based bipolar spindle depends on signals from chromatin. However, it is unknown how the spatial organization of chromatin signals affects spindle morphology. Here, we use paramagnetic chromatin beads, and magnetic fields for their alignment in cell-free extracts, to examine the spatial components of signals that regulate spindle assembly. We find that for linear chromatin-bead arrays that vary by eightfold in length, metaphase spindle size and shape are constant. Our findings indicate that, although chromatin provides cues for microtubule formation, metaphase spindle organization, which is controlled by microtubule-based motors, is robust to changes in the shape of chromatin signals.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Extracts
  • Chromatin / physiology*
  • Chromatin / ultrastructure
  • Dynactin Complex
  • Dyneins / metabolism
  • Female
  • In Vitro Techniques
  • Kinesin / metabolism
  • Metaphase / physiology*
  • Microtubule-Associated Proteins / metabolism
  • Microtubules / physiology
  • Models, Biological*
  • Oocytes / metabolism
  • Oocytes / ultrastructure
  • Signal Transduction
  • Spindle Apparatus / physiology*
  • Xenopus laevis


  • Cell Extracts
  • Chromatin
  • Dynactin Complex
  • Microtubule-Associated Proteins
  • Dyneins
  • Kinesin