Hepler P K, Callaham D A
Botany Department, University of Massachusetts, Amherst 01003.
J Cell Biol. 1987 Nov;105(5):2137-43. doi: 10.1083/jcb.105.5.2137.
Changes in free calcium concentration [( Ca]) have been detected during anaphase in stamen hair cells of Tradescantia. Cells have been injected iontophoretically with the calcium sensitive metallochromic dye arsenazo III and changes in differential absorbance have been measured using a spinning wheel microspectrophotometer. The results obtained on single cells progressing from midmetaphase through to cytokinesis show that the free [Ca] first begins in increase after the initial separation of the sister chromosomes marking the onset of anaphase. The increase continues for 10-15 min while the chromosomes move to the poles; thereafter the [Ca] declines with the cell plate appearing about the time that the ion returns to its basal level. The close temporal correlation firstly between the rise in [Ca] and the breakdown of spindle microtubules (MTs) during anaphase and secondly, between the subsequent fall in [Ca] and the emergence of the MT-containing phragmoplast provides evidence consistent with the idea that endogenous fluctuations in [Ca] control the disassembly/assembly of MTs during mitosis.
在紫露草雄蕊毛细胞的后期，已检测到游离钙浓度[Ca]的变化。通过离子电泳法向细胞中注入钙敏金属显色染料偶氮胂III，并使用旋转轮显微分光光度计测量吸光度的变化。对从中期到胞质分裂的单个细胞进行的实验结果表明，在姐妹染色单体最初分离标志着后期开始后，游离[Ca]首先开始增加。当染色体向两极移动时，这种增加持续10 - 15分钟；此后，随着细胞板出现，[Ca]下降，此时离子浓度回到基础水平。首先，后期[Ca]的升高与纺锤体微管（MTs）的解体之间存在紧密的时间相关性；其次，随后[Ca]的下降与含MT的成膜体的出现之间存在紧密的时间相关性，这提供了与以下观点一致的证据：[Ca]的内源性波动在有丝分裂期间控制MTs的拆卸/组装。
