Germline P Granules Are Liquid Droplets That Localize by Controlled Dissolution/Condensation
Germline P Granules Are Liquid Droplets That Localize by Controlled Dissolution/Condensation
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DOI：
10.1126/science.1172046
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发表时间：
2009-06-26
期刊：
影响因子：
56.9
通讯作者：
Hyman, Anthony A.
中科院分区：
文献类型：
--
作者：
Brangwynne, Clifford P.;Eckmann, Christian R.;Hyman, Anthony A.
在有性生殖的生物体中，胚胎指定生殖细胞，最终产生精子和卵子。在秀丽隐杆线虫中，当RNA和富含蛋白质的P颗粒定位于单细胞胚胎的后部时，建立了第一个生殖细胞。P颗粒的定位及其物理性质仍然知之甚少。在这里，我们表明，P颗粒表现出类似液体的行为，包括融合，滴落，润湿，我们用来估计它们的粘度和表面张力。与其他液体一样，P颗粒迅速溶解和凝结。本地化发生了一个偏向增加P颗粒凝聚在后方。这个过程反映了一个经典的相变，其中极性蛋白质改变了整个细胞的凝聚点。这种相变可能代表了细胞质结构化的基本物理化学机制。
In sexually reproducing organisms, embryos specify germ cells, which ultimately generate sperm and eggs. In Caenorhabditis elegans, the first germ cell is established when RNA and protein-rich P granules localize to the posterior of the one-cell embryo. Localization of P granules and their physical nature remain poorly understood. Here we show that P granules exhibit liquid-like behaviors, including fusion, dripping, and wetting, which we used to estimate their viscosity and surface tension. As with other liquids, P granules rapidly dissolved and condensed. Localization occurred by a biased increase in P granule condensation at the posterior. This process reflects a classic phase transition, in which polarity proteins vary the condensation point across the cell. Such phase transitions may represent a fundamental physicochemical mechanism for structuring the cytoplasm.