Drosophila Klp67A is required for proper chromosome congression and segregation during meiosis I
Abstract
Drosophila Klp67A belongs to the Kip3 subfamily of Kinesin-type microtubule catastrophe factors. In primary spermatocytes, loss of klp67A leads to defects in karyokinesis and cytokinesis. We show that these cells formed disorganised, bipolar spindles that contained increased numbers of microtubules. The kinetochore fibres were wavy and bent, whereas astral microtubules appeared abnormally robust and formed cortical bundles. Time-lapse studies revealed that during biorientation, the chromosomes in klp67A mutant cells continued to reorient for about twice as long as those in control cells. Metaphase plates were poorly defined in the mutants and often formed at non-equatorial positions. Consistent with the above abnormalities in chromosome congression, we found that in wild-type cells Klp67A associated with prometaphase/metaphase kinetochores before redistributing to the central spindle at anaphase onset. Although the timing of this redistribution of kinetochores argues against a role in anaphase chromosome segregation, dyads in the mutants disjoined but exhibited greatly diminished poleward velocities. They travelled on average at approximately 34% of the velocity of their wild-type counterparts and often decondensed at non-polar locations. Hypomorphic mutations of klp67A may lead to segregation defects.
Additional Information
© The Company of Biologists Limited 2004. Accepted March 10, 2004. We would like to thank the laboratory of G. H. Karpen for the kind gift of the chicken anti-CID antibodies. We also thank E. Mathe for helpful discussions. This work was made possible by a MRC grant to D.M.G. and grants from PAR (University of Sienna) and MIUR to M.G.R. and G.C., respectively.Attached Files
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Additional details
- Eprint ID
- 105902
- Resolver ID
- CaltechAUTHORS:20201007-150756372
- Medical Research Council (UK)
- University of Siena
- Ministero dell'Istruzione, dell'Università e della Ricerca (MIUR)
- Created
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2020-10-07Created from EPrint's datestamp field
- Updated
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2021-11-16Created from EPrint's last_modified field