Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka, Japan.
Proc Natl Acad Sci U S A. 2012 Oct 9;109(41):16737-42. doi: 10.1073/pnas.1209166109. Epub 2012 Sep 24.
Precisely arranged cytoarchitectures such as layers and nuclei depend on neuronal migration, of which many in vitro studies have revealed the mode and underlying mechanisms. However, how neuronal migration is achieved in vivo remains unknown. Here we established an imaging system that allows direct visualization of cortical interneuron migration in living mouse embryos. We found that during nucleokinesis, translocation of the Golgi apparatus either precedes or occurs in parallel to that of the nucleus, suggesting the existence of both a Golgi/centrosome-dependent and -independent mechanism of nucleokinesis. Changes in migratory direction occur when the nucleus enters one of the leading process branches, which is accompanied by the retraction of other branches. The nucleus occasionally swings between two branches before translocating into one of them, the occurrence of which is most often preceded by Golgi apparatus translocation into that branch. These in vivo observations provide important insight into the mechanisms of neuronal migration and demonstrate the usefulness of our system for studying dynamic events in living animals.
精确排列的细胞结构，如层和核，取决于神经元迁移，体外研究揭示了许多迁移的模式和潜在机制。然而，神经元迁移是如何在体内实现的仍然未知。在这里，我们建立了一个成像系统，允许在活体小鼠胚胎中直接观察皮质中间神经元的迁移。我们发现，在核迁移过程中，高尔基体的移位要么先于核迁移，要么与核迁移同时发生，这表明存在高尔基体/中心体依赖和非依赖的核迁移机制。当细胞核进入一个前导突起分支时，迁移方向会发生变化，同时其他分支会回缩。细胞核偶尔会在进入其中一个分支之前在两个分支之间摆动，这种情况的发生通常伴随着高尔基体向该分支的移位。这些体内观察为神经元迁移的机制提供了重要的见解，并证明了我们的系统在研究活体动物中的动态事件的有用性。
