Mutations in orbit/mast reveal that the central spindle is comprised of two microtubule populations, those that initiate cleavage and those that propagate furrow ingression
Abstract
We address the relative roles of astral and central spindle microtubules (MTs) in cytokinesis of Drosophila melanogaster primary spermatocytes. Time-lapse imaging studies reveal that the central spindle is comprised of two MT populations, "interior" central spindle MTs found within the spindle envelope and "peripheral" astral MTs that probe the cytoplasm and initiate cleavage furrows where they contact the cortex and form overlapping bundles. The MT-associated protein Orbit/Mast/CLASP concentrates on interior rather than peripheral central spindle MTs. Interior MTs are preferentially affected in hypomorphic orbit mutants, and consequently the interior central spindle fails to form or is unstable. In contrast, peripheral MTs still probe the cortex and form regions of overlap that recruit the Pav-KLP motor and Aurora B kinase. orbit mutants have disorganized or incomplete anillin and actin rings, and although cleavage furrows initiate, they ultimately regress. Our work identifies a new function for Orbit/Mast/CLASP and identifies a novel MT population involved in cleavage furrow initiation.
Additional Information
© The Rockefeller University Press 2004. After the Initial Publication Period, RUP will grant to the public the non-exclusive right to copy, distribute, or display the Article under a Creative Commons Attribution-Noncommercial-Share Alike 4.0 International license, as described at https://creativecommons.org/licenses/by-nc-sa/4.0/legalcode, or updates thereof. Submitted: 9 February 2004. Accepted: 27 May 2004. We would like to thank Y. Akiyama-Oda and H. Oda for the kind gifts of fly strains and C. Field for the kind gift of anillin antibodies. We wish to further acknowledge T. Sugimoto for technical assistance and C.A. Savoian for the open culture slides. This work was supported by Programme Grants from the Medical Research Council and Cancer Research UK. Y.H. Inoue received support from Grants-in-Aid for Scientific Research (A) on Priority Areas (14033224) from the Ministry of Education, Culture, Sports, Science and Technology of Japan. Y.H. Inoue and M.S. Savoian contributed equally to this paper. The online version of this article includes supplemental material.Attached Files
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Additional details
- PMCID
- PMC2172146
- Eprint ID
- 105613
- Resolver ID
- CaltechAUTHORS:20200928-150626417
- Medical Research Council (UK)
- Cancer Research UK
- 14033224
- Ministry of Education, Culture, Sports, Science and Technology (MEXT)
- Created
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2020-09-29Created from EPrint's datestamp field
- Updated
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2021-11-16Created from EPrint's last_modified field