Mitotic spindle morphogenesis in animal cells.

Assembly of the mitotic spindle is an interesting example of morphogenesis at the cellular level. The temporal control of this major event involves the periodic activation of the cyclin-cdc2 kinase complex. In this review, I report recent results that have shed some light on the temporal regulation of centrosome duplication, microtubule nucleation and microtubule dynamics. Reorganization of highly dynamic microtubules into a bipolar spindle probably requires kinesin and dynein-like motors and their role is discussed in an hypothetical model that may be applicable to all mitotic spindles.