MRC Centre for Stem Cell Biology and Regenerative Medicine and Department of Veterinary Medicine, University of Cambridge, Cambridge, United Kingdom.
Glia. 2010 May;58(7):802-12. doi: 10.1002/glia.20964.
Knowledge of the precise timing of myelination is critical to the success of zebrafish-based in vivo screening strategies for potential remyelination therapies. This study provides a systematic review of the timing of myelination in the zebrafish spinal cord and a critique of techniques by which it may be accurately assessed. The onset of myelination was found to be 3 days postfertilization (d.p.f.); earlier than previously reported. This coincided with the dorsal migration and differentiation of oligodendrocytes and the expression of myelin basic protein (Mbp) transcripts and protein. Our data suggests that immunohistochemistry with zebrafish-specific anti-Mbp from 3 d.p.f. is the optimal histological method for myelin visualization, while quantification of myelination is more reliably achieved by quantitative polymerase chain reaction (qPCR) for mbp from 5 d.p.f.. Transgenic fluorescent lines such as olig2:EGFP can be used to assess oligodendrocyte cell number at 3 d.p.f. and the development of new, more specific lines may enable real time visualization of myelin itself. Quantitative ultrastructural analysis revealed that the myelination of zebrafish axons is regulated according to axonal growth and not absolute axonal size. This study confirms the use of the zebrafish larvae as a versatile and efficient in vivo model of myelination and provides a platform on which future myelination screening studies can be based.
髓鞘形成的确切时间的知识对于基于斑马鱼的体内筛选潜在髓鞘再生疗法的成功至关重要。本研究对斑马鱼脊髓髓鞘形成的时间进行了系统综述，并对准确评估髓鞘形成的技术进行了评价。髓鞘形成的起始时间为受精后 3 天（d.p.f.）；早于先前的报道。这与少突胶质细胞的背侧迁移和分化以及髓鞘碱性蛋白（Mbp）转录本和蛋白的表达同时发生。我们的数据表明，从 3 d.p.f.开始用针对斑马鱼的特异性抗 Mbp 进行免疫组织化学染色是显示髓鞘的最佳组织学方法，而从 5 d.p.f.开始用 Mbp 的定量聚合酶链反应（qPCR）进行髓鞘定量更为可靠。像 olig2:EGFP 这样的转基因荧光系可用于在 3 d.p.f.评估少突胶质细胞数量，并且新的、更具特异性的系的发展可能使髓鞘本身的实时可视化成为可能。定量超微结构分析表明，斑马鱼轴突的髓鞘形成是根据轴突生长而不是绝对轴突大小来调节的。本研究证实了将斑马鱼幼虫用作髓鞘化的多功能和高效体内模型，并为未来的髓鞘化筛选研究提供了一个平台。
