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Active forces shape the metaphase spindle through a mechanical instability.

ABSTRACT: The metaphase spindle is a dynamic structure orchestrating chromosome segregation during cell division. Recently, soft matter approaches have shown that the spindle behaves as an active liquid crystal. Still, it remains unclear how active force generation contributes to its characteristic spindle-like shape. Here we combine theory and experiments to show that molecular motor-driven forces shape the structure through a barreling-type instability. We test our physical model by titrating dynein activity in Xenopus egg extract spindles and quantifying the shape and microtubule orientation. We conclude that spindles are shaped by the interplay between surface tension, nematic elasticity, and motor-driven active forces. Our study reveals how motor proteins can mold liquid crystalline droplets and has implications for the design of active soft materials.

SUBMITTER: Oriola D

PROVIDER: S-EPMC7368317 | biostudies-literature | 2020 Jul

REPOSITORIES: biostudies-literature

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Active forces shape the metaphase spindle through a mechanical instability.

Oriola David D Jülicher Frank F Brugués Jan J

Proceedings of the National Academy of Sciences of the United States of America 20200629 28

The metaphase spindle is a dynamic structure orchestrating chromosome segregation during cell division. Recently, soft matter approaches have shown that the spindle behaves as an active liquid crystal. Still, it remains unclear how active force generation contributes to its characteristic spindle-like shape. Here we combine theory and experiments to show that molecular motor-driven forces shape the structure through a barreling-type instability. We test our physical model by titrating dynein act ...[more]

PMID: 32601228

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