New concept of microtubule dynamics and microtubule motor movement and new model of chromosome movement in mitosis.

In this study, microtubules are regarded as polymers with positive free surface energy. The dynamics of such polymers is complex, consisting of equilibrium, non-equilibrium, and one-directional processes. This view of microtubules enables us to propose a new model of microtubule dynamics both in vitro and in vivo, and to draw a new conclusion on the role of GTP hydrolysis and calcium cations in microtubule polymerization. The study also offers a new model of chromosome movement in mitosis and a new model of the movement of motor proteins along microtubules. In the conclusion of the similarity and difference between microtubules and microfilaments is examined. We conclude that microfilaments, like microtubules, represent polymers with positive free surface energy, and that the movement of myosins along microfilaments can be realized in the same manner as the movement of motor proteins along microtubules.