Measurements of the force produced by the mitotic spindle in anaphase.
Measurements of the force produced by the mitotic spindle in anaphase.
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DOI：
10.1083/jcb.97.2.542
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发表时间：
1983-08
期刊：
影响因子：
--
通讯作者：
Nicklas RB
中科院分区：
文献类型：
--
作者：
Nicklas RB
使用柔性玻璃针测量纺锤体在后期对单个移动染色体施加的力，该玻璃针以每微米尖端偏转的达因进行校准。针用于在染色体上产生力，该力与纺锤体产生的力相反，并且可以通过针尖偏转来测量。在证明细胞表面等材料的存在不会干扰后，在完整的蚱蜢精母细胞中进行了测量。在7个细胞中进行12次实验的结果如下：直到反作用力达到大约10(-5)达因时，染色体速度才受到影响，然后随着作用力的增加而迅速下降。导致染色体速度降至零的反作用力（与纺锤体可以产生的最大力相匹配的力）的量级为 7 X 10(-5) dyn。这个直接测量的最大力势比正常染色体运动的10(-8) dyn的计算值大近10,000倍，其中仅需要克服运动的粘性阻力。纺锤体出乎意料的巨大力潜力促使人们重新审视有丝分裂马达的分子模型、限速调节器以及力有时可能影响微管长度和稳定性的可能性。
The force the spindle exerts on a single moving chromosome in anaphase was measured with a flexible glass needle calibrated in dynes per micron of tip deflection. The needle was used to produce a force on the chromosome, which opposed that produced by the spindle and was measurable from needle tip deflection. The measurements were made in intact grasshopper spermatocytes after proving that the presence of materials such as the cell surface did not interfere. The results from 12 experiments in seven cells are as follows: Chromosome velocity was not affected until the opposing force reached approximately 10(-5) dyn, and then fell rapidly with increasing force. The opposing force that caused chromosome velocity to fall to zero--the force that matched the maximum force the spindle could produce--was of order 7 X 10(-5) dyn. This directly measured maximum force potential is nearly 10,000 times greater than the calculated value of 10(-8) dyn for normal chromosome movement, in which only viscous resistance to movement must be overcome. The spindle's unexpectedly large force potential prompts a fresh look at molecular models for the mitotic motor, at velocity- limiting governors, and at the possibility that force may sometimes affect microtubule length and stability.