Microtubule amplification in the assembly of mitotic spindle and the maturation of kinetochore fibers

Efficient assembly of a mitotic spindle and stable attachment of microtubules (k-fibers) to kinetochores are essential for the high fidelity of chromosome segregation. Both spindle assembly and Mitotic spindle mediates the segregation of chromosomes in the cell cycle and the proper function of the spindle is crucial to the high fidelity of chromosome segregation and to the stability of the genome. Nucleation of microtubules (MTs) from centrosomes and chromatin represents two well-characterized pathways essential for the assembly of a dynamic spindle in mitosis. Recently, we identified a third MT nucleation pathway, in which existing MTs in the spindle acts as a template to promote the nucleation and polymerization of MTs, thereby efficiently amplifying MTs in the spindle. We will review here our current understanding on the molecular mechanism, the physiological function and the cell-cycle regulation of MT amplification.k-fiber formation require robust nucleation and polymerization of microtubules mediate...