ULTIMATE COMPUTING - Quantum Consciousness Studies

Cytoskeleton/Cytocomputer 95
Figure 5.10: DeBrabander’s model of MTOC action. Upper left: A centriole is
surrounded by a dense material that lowers Cc, the critical concentration of
tubulin required for microtubule assembly. At the beginning of mitosis, new MT
are preferentially nucleated near the MTOC. Upper right: Kinetochore plates
associated with chromosomes also have the Cc lowering material but anchor plus
ends; new MT form. Middle: MT minus ends are stabilized by the pericentriolar
dense material and plus ends grow outward. Free MT are unstabilized and remain
short due to consumption of tubulin subunits by MTOC stabilized MT. Bottom:
stabilized MT slide along one another to pull chromosomes apart. With
permission from Marc DeBrabander (1982).