Stoichiometric interactions explain spindle dynamics and scaling across 100 million years of nematode evolution.
Stoichiometric interactions explain spindle dynamics and scaling across 100 million years of nematode evolution.
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DOI：
10.7554/elife.55877
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发表时间：
2020-09-23
期刊：
影响因子：
7.7
通讯作者：
Needleman DJ
中科院分区：
文献类型：
--
作者：
Farhadifar R;Yu CH;Fabig G;Wu HY;Stein DB;Rockman M;Müller-Reichert T;Shelley MJ;Needleman DJ
纺锤体显示出显著的多样性，并且随着细胞在进化过程中的变化而以整合的方式变化。在这里，我们提供了一个机械的解释，在线虫的第一个有丝分裂纺锤体的变化。我们使用了数量遗传学和生物物理学的结合，以排除纺锤体长度和动力学调节的广泛类别的模型，并建立在不同方向上作用的皮质拉力平衡的重要性。这些实验使我们构建了一个皮质拉力模型，其中微管和力发生器（每个力发生器只能结合一个微管）的化学计量相互作用是解释纺锤体定位和伸长以及纺锤体最终长度和细胞大小缩放的动力学的关键。这个模型解释了我们在这里研究的所有纺锤体特征的变化，包括物种内和跨越1亿多年进化的线虫物种。
The spindle shows remarkable diversity, and changes in an integrated fashion, as cells vary over evolution. Here, we provide a mechanistic explanation for variations in the first mitotic spindle in nematodes. We used a combination of quantitative genetics and biophysics to rule out broad classes of models of the regulation of spindle length and dynamics, and to establish the importance of a balance of cortical pulling forces acting in different directions. These experiments led us to construct a model of cortical pulling forces in which the stoichiometric interactions of microtubules and force generators (each force generator can bind only one microtubule), is key to explaining the dynamics of spindle positioning and elongation, and spindle final length and scaling with cell size. This model accounts for variations in all the spindle traits we studied here, both within species and across nematode species spanning over 100 million years of evolution.