Microtubule-depolymerizing kinesin KLP10A restricts the length of the acentrosomal meiotic spindle in Drosophila females.

During cell division, a bipolar array of microtubules forms the spindle through which the forces required for chromosome segregation are transmitted. Interestingly, the spindle as a whole is stable enough to support these forces even though it is composed of dynamic microtubules, which are constantly undergoing periods of growth and shrinkage. Indeed, the regulation of microtubule dynamics is essential to the integrity and function of the spindle. We show here that a member of an important class of microtubule-depolymerizing kinesins, KLP10A, is required for the proper organization of the acentrosomal meiotic spindle in Drosophila melanogaster oocytes. In the absence of KLP10A, microtubule length is not controlled, resulting in extraordinarily long and disorganized spindles. In addition, the interactions between chromosomes and spindle microtubules are disturbed and can result in the loss of contact. These results indicate that the regulation of microtubule dynamics through KLP10A plays a critical role in restricting the length and maintaining bipolarity of the acentrosomal meiotic spindle and in promoting the contacts that the chromosomes make with microtubules required for meiosis I segregation.