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Cleavage furrow establishment by the moving mitotic apparatus
1The Mount Desert Island Biological Laboratory, Salsbury Cove, Maine 04672, USA.
Development, Growth & Differentiation
|April 1, 1997
Summary
Cell division does not require a static mitotic apparatus. Moving the mitotic apparatus in sand dollar eggs shows the division mechanism can still establish, even when disrupted.
Area of Science:
- Cell Biology
- Developmental Biology
- Cytokinesis
Background:
- The establishment of the cell division plane is crucial for cell proliferation.
- Traditionally, a static relationship between the mitotic apparatus and the division plane has been considered essential for this process.
Purpose of the Study:
- To investigate if disrupting the static relationship between the mitotic apparatus and the division plane affects the establishment of the division mechanism.
- To determine the role of mitotic apparatus positioning in cell division.
Main Methods:
- Sand dollar eggs were experimentally reshaped into cylinders.
- The mitotic apparatus was subjected to controlled, reciprocal motion before cleavage.
- Furrowing activity was observed under different movement conditions (continuous vs. discontinuous) and excursion distances.
Main Results:
- Continuous movement of the mitotic apparatus resulted in furrowing near its midpoint, with decreased acuteness correlating with increased movement distance.
- Discontinuous movement with short pauses led to furrowing at the midpoint, while longer pauses induced furrowing at pause sites.
- The results demonstrate that a fixed position of the mitotic apparatus is not necessary for establishing the division mechanism.
Conclusions:
- The normal static relationship between the mitotic apparatus and the division plane is not essential for establishing the cell division mechanism.
- A localized contractile cortex can form independently of a static mitotic apparatus, even with experimentally induced disruption.
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