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Chromosomal attachments set length and microtubule number in the Saccharomyces cerevisiae mitotic spindle.

ABSTRACT: 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 length scales with kinetochore number, increasing when kinetochores are inactivated and shortening on addition of synthetic or natural kinetochores, showing that kinetochore-microtubule interactions generate an inward force to balance forces that elongate the spindle. Electron microscopy shows that manipulating kinetochore number alters the number of spindle microtubules: adding extra kinetochores increases the number of spindle microtubules, suggesting kinetochore-based regulation of microtubule number.

SUBMITTER: Nannas NJ

PROVIDER: S-EPMC4263447 | biostudies-literature | 2014 Dec

REPOSITORIES: biostudies-literature

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Chromosomal attachments set length and microtubule number in the Saccharomyces cerevisiae mitotic spindle.

Nannas Natalie J NJ O'Toole Eileen T ET Winey Mark M Murray Andrew W AW

Molecular biology of the cell 20141015 25

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 length scales with kinetochore number, increasing when kinetochores are inactivated and shortening on addit ...[more]

PMID: 25318669

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