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| Functional Role of Interzonal Microtubules in Cytokinesis |
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| S.P. Wheatley and Y.-l. Wang (1996) |
| J. Cell Biol. 135:981-989. |
| To determine the relationship between interzonal microtubules and cytokinesis, we have studied NRK cells that contained an abnormal tripolar spindle. Microtubules dynamics was visualized by microinjecting cells with rhodamine-labeled tubulin. |
| Division of a Tri-Polar Cell into Three Daughter Cells |
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Size = 360 x 240 pixels.| Some abnormal cells form three spindle poles instead of two during division. When interzonal microtubules are present between each pair of spindle poles, the cell divides into three daughter cells. |
| Division of a Tri-Polar Cell into Two Daughter Cells |
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Size = 284 x 236 pixels.| In this tri-polar cell, interzonal microtubules between the upper pair of spindle poles moved downward and became incorporated into other interzonal regions. No furrowing occured in the upper region and this cell divided into two daughter cells. These observations suggest that the site of cleavage is defined by the distribution of interzonal microtubules. |
| Division after Treatment with Nocodazole |
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Size = 360 x 240 pixels.| This cell was microinjected with rhodamine-labeled tubulin and treated with nocodazole to depolymerize microtubules during anaphase. While most microtubules disappeared, some interzonal microtubule bundles were resistant to the drug. The cell cleaved along a curved path, with the advancing edge of the furrow following the residual microtubule bundles. This observation adds additional evidence that the site of cleavage is defined by interzonal microtubule bundles, which in turn may be anchored by other microtubules susceptible to nocodazole treatment. |