Huang Sui
Institute for Systems Biology, Seattle, Washington.
PLoS Biol. 2016 May 19;14(5):e1002463. doi: 10.1371/journal.pbio.1002463. eCollection 2016 May.
Cell migration in the "correct" direction is pivotal for many biological processes. Although most work is devoted to its molecular mechanisms, the cell's preference for one direction over others, thus overcoming intrinsic random motility, epitomizes a profound principle that underlies all complex systems: the choice of one axis, in structure or motion, from a uniform or symmetric set of options. Explaining directional motility by an external chemo-attractant gradient does not solve but only shifts the problem of causation: whence the gradient? A new study in PLOS Biology shows cell migration in a self-generated gradient, offering an opportunity to take a broader look at the old dualism of extrinsic instruction versus intrinsic symmetry-breaking in cell biology.
细胞沿“正确”方向迁移对许多生物学过程至关重要。尽管大多数研究致力于其分子机制，但细胞对一个方向而非其他方向的偏好，从而克服内在的随机运动，体现了一个深刻的原则，该原则是所有复杂系统的基础：从一组均匀或对称的选项中选择一个结构或运动轴。用外部化学引诱剂梯度来解释定向运动并不能解决问题，而只是转移了因果关系的问题：梯度从何而来？发表在《公共科学图书馆·生物学》上的一项新研究表明，细胞在自我产生的梯度中迁移，这为更广泛地审视细胞生物学中外在指令与内在对称性破缺的旧二元论提供了一个契机。
