Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany.
Center for Systems Biology, Dresden, Germany.
Nat Cell Biol. 2018 Mar;20(3):344-351. doi: 10.1038/s41556-017-0032-9. Epub 2018 Feb 5.
Recent advances in cell biology enable precise molecular perturbations. The spatiotemporal organization of cells and organisms, however, also depends on physical processes such as diffusion or cytoplasmic flows, and strategies to perturb physical transport inside cells are not yet available. Here, we demonstrate focused-light-induced cytoplasmic streaming (FLUCS). FLUCS is local, directional, dynamic, probe-free, physiological, and is even applicable through rigid egg shells or cell walls. We explain FLUCS via time-dependent modelling of thermoviscous flows. Using FLUCS, we demonstrate that cytoplasmic flows drive partitioning-defective protein (PAR) polarization in Caenorhabditis elegans zygotes, and that cortical flows are sufficient to transport PAR domains and invert PAR polarity. In addition, we find that asymmetric cell division is a binary decision based on gradually varying PAR polarization states. Furthermore, the use of FLUCS for active microrheology revealed a metabolically induced fluid-to-solid transition of the yeast cytoplasm. Our findings establish how a wide range of transport-dependent models of cellular organization become testable by FLUCS.
细胞生物学的最新进展使精确的分子扰动成为可能。然而，细胞和生物体的时空组织也依赖于扩散或细胞质流动等物理过程，并且目前还没有用于扰乱细胞内物理传输的策略。在这里，我们展示了聚焦光诱导的细胞质流动（FLUCS）。FLUCS 具有局部性、方向性、动态性、无探针性、生理性，甚至可以穿过刚性的卵壳或细胞壁。我们通过时变热粘性流的建模来解释 FLUCS。利用 FLUCS，我们证明了细胞质流动驱动了秀丽隐杆线虫合子中分配缺陷蛋白（PAR）的极化，并且皮层流动足以运输 PAR 结构域并反转 PAR 极性。此外，我们发现不对称细胞分裂是基于 PAR 极化状态逐渐变化的二元决策。此外，FLUCS 用于主动微流变学的应用揭示了酵母细胞质中代谢诱导的从流体到固体的转变。我们的研究结果表明，FLUCS 可以验证广泛的依赖于运输的细胞组织模型。
