Mitotic spindle scaling during Xenopus development by kif2a and importin α
Open Access
- 19 February 2013
- journal article
- video audio-media
- Published by eLife Sciences Publications, Ltd in eLife
- Vol. 2, e00290
- https://doi.org/10.7554/elife.00290
Abstract
Early development of many animals is characterized by rapid cleavages that dramatically decrease cell size, but how the mitotic spindle adapts to changing cell dimensions is not understood. To identify mechanisms that scale the spindle during Xenopus laevis embryogenesis, we established an in vitro system using cytoplasmic extracts prepared from embryos that recapitulates in vivo spindle size differences between stage 3 (4 cells, 37 µm) and stage 8 (∼4000 cells, 18 µm). We identified the kinesin-13 kif2a as a driver of developmental spindle scaling whose microtubule-destabilizing activity is inhibited in stage 3 spindles by the transport receptor importin α, and activated in stage 8 when importin α partitions to a membrane pool. Altering spindle size in developing embryos impaired spindle orientation during metaphase, but chromosome segregation remained robust. Thus, spindle size in Xenopus development is coupled to cell size through a ratiometric mechanism controlling microtubule destabilization.Funding Information
- National Institutes of Health (R01GM098766)
- National Institutes of Health (R01GM098766)
This publication has 36 references indexed in Scilit:
- The transition from meiotic to mitotic spindle assembly is gradual during early mammalian developmentThe Journal of cell biology, 2012
- Organelle Growth Control through Limiting Pools of Cytoplasmic ComponentsCurrent Biology, 2012
- Nucleation and Transport Organize Microtubules in Metaphase SpindlesCell, 2012
- Centrosome Size Sets Mitotic Spindle Length in Caenorhabditis elegans EmbryosCurrent Biology, 2010
- Xenopus tropicalis egg extracts provide insight into scaling of the mitotic spindleThe Journal of cell biology, 2007
- Efficient Mitosis in Human Cells Lacking Poleward Microtubule FluxCurrent Biology, 2005
- Dynein/dynactin regulate metaphase spindle length by targeting depolymerizing activities to spindle polesThe Journal of cell biology, 2004
- The KinI kinesin Kif2a is required for bipolar spindle assembly through a functional relationship with MCAKThe Journal of cell biology, 2004
- Ran–GTP coordinates regulation of microtubule nucleation and dynamics during mitotic-spindle assemblyNature, 2001
- Ran Induces Spindle Assembly by Reversing the Inhibitory Effect of Importin α on TPX2 ActivityCell, 2001