Wu Hai-Yin, Nazockdast Ehssan, Shelley Michael J, Needleman Daniel J
Department of Physics, Harvard University, Cambridge, MA, USA.
Faculty of Arts and Sciences Center for Systems Biology, Harvard University, Cambridge, MA, USA.
Bioessays. 2017 Feb;39(2). doi: 10.1002/bies.201600212. Epub 2016 Dec 27.
The position of the spindle determines the position of the cleavage plane, and is thus crucial for cell division. Although spindle positioning has been extensively studied, the underlying forces ultimately responsible for moving the spindle remain poorly understood. A recent pioneering study by Garzon-Coral et al. uses magnetic tweezers to perform the first direct measurements of the forces involved in positioning the mitotic spindle. Combining this with molecular perturbations and geometrical effects, they use their data to argue that the forces that keep the spindle in its proper position for cell division arise from astral microtubules growing and pushing against the cell's cortex. Here, we review these ground-breaking experiments, the various biomechanical models for spindle positioning that they seek to differentiate, and discuss new questions raised by these measurements.
纺锤体的位置决定了分裂平面的位置，因此对细胞分裂至关重要。尽管纺锤体定位已得到广泛研究，但最终负责移动纺锤体的潜在力量仍知之甚少。加尔松 - 科拉尔等人最近的一项开创性研究使用磁性镊子首次直接测量了有丝分裂纺锤体定位过程中涉及的力。他们将此与分子扰动和几何效应相结合，利用数据论证，使纺锤体在细胞分裂时保持在适当位置的力来自星状微管生长并推向细胞皮层。在此，我们回顾这些开创性实验、他们试图区分的各种纺锤体定位生物力学模型，并讨论这些测量提出的新问题。
