The length of the mitotic spindle varies among different cell types. A simple model for spindle length regulation requires balancing two forces: pulling, due to micro-tubules that attach to the chromosomes at their kinetochores, and pushing, due to interactions between microtubules that emanate from opposite spindle poles. In the budding yeast Saccharomyces cerevisiae, we show that spindle leng...

During anaphase, the nonkinetochore microtubules in the spindle midzone become compacted into the central spindle, a structure which is required to both initiate and complete cytokinesis. We show that Tektin 2 (Tek2) associates with the spindle poles throughout mitosis, organizes the spindle midzone microtubules during anaphase, and assembles into the midbody matrix surrounding the compacted mi...

Spontaneous and sensory evoked spindle bursts represent a functional hallmark of the developing cerebral cortex in vitro and in vivo. They have been observed in various neocortical areas of numerous species, including newborn rodents and preterm human infants. Spindle bursts are generated in complex neocortical-subcortical circuits involving in many cases the participation of motor brain region...

Faithful action of the mitotic spindle segregates duplicated chromosomes into daughter cells. Perturbations of this process result in chromosome mis-segregation, leading to chromosomal instability and cancer development. Chromosomes are not simply passengers segregated by spindle microtubules but rather play a major active role in spindle assembly. The GTP bound form of the Ran GTPase (RanGTP),...

At the end of the cell cycle a cell physically divides into two daughter cells in a process called cytokinesis. Cytokinesis consists of at least four steps: (1) The position of the presumptive cytokinesis furrow is specified. (2) A contractile ring is formed. (3) The contractile ring contracts, resulting in furrow ingression. (4) Cytokinesis completes with sealing of the membranes. The mitotic ...

During cell division, the molecular motor Eg5 crosslinks overlapping antiparallel microtubules and pushes them apart to separate mitotic spindle poles. Dynein has been proposed as a direct antagonist of Eg5 at the spindle equator, pulling on antiparallel microtubules and favoring spindle collapse. Some of the experiments supporting this hypothesis relied on endpoint quantifications of spindle p...

Spindle assembly required during mitosis depends on microtubule polymerization. We demonstrate that the evolutionarily conserved low-complexity protein, BuGZ, undergoes phase transition or coacervation to promote assembly of both spindles and their associated components. BuGZ forms temperature-dependent liquid droplets alone or on microtubules in physiological buffers. Coacervation in vitro or ...

In the process of cell division, chromosomes are segregated by mitotic spindles -- bipolar microtubule arrays that have a characteristic fusiform shape. Mitotic spindle function is based on motor-generated forces of hundreds of piconewtons. These forces have to deform the spindle, yet the role of microtubule elastic deformations in the spindle remains unclear. Here we solve equations of elastic...

In many eucaryotic cells, the midzone of the mitotic spindle forms a distinct structure containing a specific set of proteins. We have isolated ASE1, a gene encoding a component of the Saccharomyces cerevisiae spindle midzone. Strains lacking both ASE1 and BIK1, which encodes an S. cerevisiae microtubule-associated protein, are inviable. The analysis of the phenotype of a bik1 ase1 conditional ...

it was first introduced by Enzinger and Harvey (1). The three principal components of spindle cell lipoma are mature adipocytes, small, undifferentiated spindle cells and short bundles of brightly eosinophilic collagen that are associated with the spindle cells. The relative proportion of these three elements within a given lesion varies quite markedly, with the spindle cell areas accounting fo...