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Analysis of microtubule movement on isolated Xenopus egg cortices provides evidence that the cortical rotation involves dynein as well as Kinesin Related Proteins and is regulated by local microtubule polymerisation
- Source :
- Developmental biology. 257(1)
- Publication Year :
- 2003
-
Abstract
- In amphibians, the cortical rotation, a translocation of the egg cortex relative to the cytoplasm, specifies the dorsoventral axis. The cortical rotation involves an array of subcortical microtubules whose alignment is mediated by Kinesin–related proteins (KRPs), and stops as M-phase promoting factor (MPF) activation propagates across the egg. To dissect the role of different motor proteins in the cortical rotation and to analyse their regulation, we have developed an open cell assay system involving reactivation of microtubule movement on isolated cortices. Microtubule movements were dependent on ATP and consisted mainly of wriggling and flailing without net displacement, consistent with a tethering of microtubules to the cortex. Reactivated movements were inhibited by anti-KRP and anti-dynein antibodies perfused together but not separately, the KRP antibody alone becoming fixed to the cortex. Neither antibody could inhibit movement in the presence of MPF, indicating that arrest of the cortical rotation is not due to MPF-dependent inhibition of motor molecules. In contrast, D2O treatment of live eggs to protect microtubules from progressive depolymerisation prolonged the cortical rotation. We conclude that the cortical rotation probably involves cytoplasmic dynein as well as cortical KRPs and terminates as a result of local MPF-dependent microtubule depolymerisation.
- Subjects :
- Xenopus
Dynein
Maturation-Promoting Factor
Kinesins
Mitosis
Biology
Microtubules
Motor protein
Adenosine Triphosphate
Microtubule
Cortex (anatomy)
Molecular motor
medicine
Animals
Molecular Biology
Ovum
Microscopy, Confocal
Staining and Labeling
Rhodamines
Dyneins
Molecular motors
Cell Biology
biology.organism_classification
Cell biology
medicine.anatomical_structure
Xenopus egg extracts
Cytoplasm
Kinesin
Maturation/M-phase promoting factor (MPF)
Female
Developmental Biology
Subjects
Details
- ISSN :
- 00121606
- Volume :
- 257
- Issue :
- 1
- Database :
- OpenAIRE
- Journal :
- Developmental biology
- Accession number :
- edsair.doi.dedup.....0d126d7b7913df9b69e504393c72c64a