Department of Microbiology and Immunology, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA.
Cell. 2011 Feb 4;144(3):414-26. doi: 10.1016/j.cell.2011.01.016.
The spatial organization of cells depends on their ability to sense their own shape and size. Here, we investigate how cell shape affects the positioning of the nucleus, spindle and subsequent cell division plane. To manipulate geometrical parameters in a systematic manner, we place individual sea urchin eggs into microfabricated chambers of defined geometry (e.g., triangles, rectangles, and ellipses). In each shape, the nucleus is positioned at the center of mass and is stretched by microtubules along an axis maintained through mitosis and predictive of the future division plane. We develop a simple computational model that posits that microtubules sense cell geometry by probing cellular space and orient the nucleus by exerting pulling forces that scale to microtubule length. This model quantitatively predicts division-axis orientation probability for a wide variety of cell shapes, even in multicellular contexts, and estimates scaling exponents for length-dependent microtubule forces.
细胞的空间组织取决于它们感知自身形状和大小的能力。在这里，我们研究细胞形状如何影响核、纺锤体和随后的细胞分裂面的定位。为了系统地操纵几何参数，我们将单个海胆卵放入具有明确定义几何形状的微加工室中（例如三角形、矩形和椭圆形）。在每种形状中，核位于质心处，并沿通过有丝分裂保持且可预测未来分裂面的轴被微管拉伸。我们开发了一个简单的计算模型，该模型假设微管通过探测细胞空间来感知细胞几何形状，并通过施加与微管长度成比例的拉力来定向核。该模型定量预测了各种细胞形状的分裂轴取向概率，即使在多细胞环境中也是如此，并估计了长度依赖性微管力的标度指数。
