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

• Published in: Nature cell biology Vol. 8; no. 9; pp. 924 - 932
• Main Authors: Gaetz, Jedidiah, Gueroui, Zoher, Libchaber, Albert, Kapoor, Tarun M
• Format: Journal Article
• Language: English
• Published: England Nature Publishing Group 01.09.2006
• Subjects: Animals; Cell division; Cell Extracts; Chromatin; Chromatin - physiology; Chromatin - ultrastructure; DNA; Dynactin Complex; Dyneins - metabolism; Female; In Vitro Techniques; Kinesin - metabolism; Magnetic fields; Metaphase - physiology; Microtubule-Associated Proteins - metabolism; Microtubules - physiology; Models, Biological; Oocytes - metabolism; Oocytes - ultrastructure; Signal Transduction; Spindle (Cell division); Spindle Apparatus - physiology; Xenopus laevis
• ISSN: 1465-7392; 1476-4679
• DOI: 10.1038/ncb1455

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.