Active diffusion positions the nucleus in mouse oocytes
Active diffusion positions the nucleus in mouse oocytes
复制标题
DOI：
10.1038/ncb3131
复制
发表时间：
2015-04-01
影响因子：
21.3
通讯作者：
Verlhac, Marie-Helene
中科院分区：
文献类型：
--
作者：
Almonacid, Maria;Ahmed, Wylie W.;Verlhac, Marie-Helene
在体细胞中，细胞质心的位置由中心体决定。中心体在细胞核定位中起着重要作用，这两个结构在物理上是相连的。小鼠卵母细胞没有中心体，但有位于中心的核。我们演示了在没有中心体的情况下，卵母细胞如何定义它们的几何中心。利用卵母细胞的实时成像，敲除Forin 2肌动蛋白核仁，细胞核偏心，再加上光学捕获和建模，我们发现了一种前所未有的细胞核定位模式。我们记录了肌球蛋白VB驱动的肌动蛋白包裹的囊泡如何主动扩散，产生足以移动卵母细胞核的压力梯度和推进力。它促进细胞质的流态化，有助于细胞核向中心定向移动。我们的结果突出了主动扩散的潜力，它是细胞内运输的一个重要来源，能够移动细胞核等大型细胞器，为其生物功能提供了体内证据。
In somatic cells, the position of the cell centroid is dictated by the centrosome. The centrosome is instrumental in nucleus positioning, the two structures being physically connected. Mouse oocytes have no centrosomes, yet harbour centrally located nuclei. We demonstrate how oocytes define their geometric centre in the absence of centrosomes. Using live imaging of oocytes, knockout for the formin 2 actin nucleator, with off-centred nuclei, together with optical trapping and modelling, we discover an unprecedented mode of nucleus positioning. We document how active diffusion of actin-coated vesicles, driven by myosin Vb, generates a pressure gradient and a propulsion force sufficient to move the oocyte nucleus. It promotes fluidization of the cytoplasm, contributing to nucleus directional movement towards the centre. Our results highlight the potential of active diffusion, a prominent source of intracellular transport, able to move large organelles such as nuclei, providing in vivo evidence of its biological function.