Abstract
The completion of cytokinesis is dominated by the midbody, a tightly-packed microtubule (MT)-based bridge that transiently connects the two daughter cells. Assembled from condensed, spindle-MTs and numerous associated proteins, the midbody gradually narrows down until daughter cell partitioning occurs at this site. Although described many years ago, detailed understanding of the abscission process remains lacking. Applying cryo-electron tomography to purified midbodies, in combination with fluorescence microscopy, we present here new insight into MT organization within the midbody. We find that the midbody is spatially divided into a core bundle of MTs that traverses the electron-dense overlap region (continuous MTs), surrounded by MTs that terminate within the overlap region (polar MTs). Residual continuous MTs remained intact up to the verge of abscission, whereas the residual polar MTs lost their organization and retreated from the overlap region at late cytokinesis stages. A detailed localization of the microtubule-bundling protein PRC1 supports the above notion. Our study thus provides a detailed account of the abscission process and suggests that the midbody, having acquired a distinct MT architecture as compared to the preceding central spindle, actively facilitates the final stage of cytokinesis.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.