INSERM, UMRS_U968, Institut de la Vision, Paris, F-75012, France; Sorbonne Universités, UPMC Univ Paris 06, Institut de la Vision, Paris, F-75012, France; CNRS, UMR_7210, Paris, F-75012, France.
Glia. 2015 Apr;63(4):699-717. doi: 10.1002/glia.22779. Epub 2014 Dec 21.
Oligodendrocytes are the myelinating cells of the central nervous system. Multiple markers are available to analyze the populations of oligodendroglial cells and their precursors during development and in pathological conditions. However, the behavior of oligodendrocytes remains poorly characterized in vivo, especially at the level of individual cells. Studying this aspect has been impaired so far by the lack of suitable methods for visualizing single oligodendrocytes, their processes, and their interactions during myelination. Here, we have used multicolor labeling technology to single-out simultaneously many individual oligodendrocytes in the postnatal mouse optic nerve. This method is based on Brainbow, a transgenic system for stochastic expression of multiple fluorescent protein genes through Cre-lox recombination, previously used for visualizing axons and neurons. We used tamoxifen-inducible recombination in myelinating cells of Brainbow transgenic mice to obtain multicolor labeling of oligodendrocytes. We show that the palette of colors expressed by labeled oligodendrocytes is tamoxifen dependent, with the highest doses producing the densest and most colorful labeling. At low doses of tamoxifen, the morphology of single or small clusters of fluorescent oligodendrocytes can be studied during postnatal development and in adult. Internodes are labeled to their extremities, revealing nodes of Ranvier. The new mouse model presented here opens new possibilities to explore the organization and development of the oligodendrocyte network with single-cell resolution.
少突胶质细胞是中枢神经系统的髓鞘形成细胞。有多种标记物可用于分析发育过程中和病理条件下少突胶质细胞及其前体细胞的群体。然而，少突胶质细胞的行为在体内仍未得到很好的描述，尤其是在单个细胞水平上。到目前为止，由于缺乏合适的方法来可视化单个少突胶质细胞、其过程及其在髓鞘形成过程中的相互作用，研究这一方面受到了阻碍。在这里，我们使用多色标记技术在新生小鼠视神经中同时分离出许多单个少突胶质细胞。该方法基于 Brainbow，这是一种通过 Cre-lox 重组随机表达多种荧光蛋白基因的转基因系统，以前曾用于可视化轴突和神经元。我们使用 tamoxifen 诱导的重组在 Brainbow 转基因小鼠的髓鞘细胞中获得少突胶质细胞的多色标记。我们表明，标记少突胶质细胞表达的颜色谱依赖于 tamoxifen，高剂量产生最密集和最丰富多彩的标记。在 tamoxifen 的低剂量下，可以在出生后发育和成年期间研究单个或小簇荧光少突胶质细胞的形态。节间段被标记到其末端，揭示了郎飞结。这里介绍的新小鼠模型为探索具有单细胞分辨率的少突胶质细胞网络的组织和发育提供了新的可能性。
