Characterization of myelination in the developing zebrafish
Characterization of myelination in the developing zebrafish
复制标题
DOI：
10.1002/glia.10088
复制
发表时间：
2002-07-01
期刊：
影响因子：
6.2
通讯作者：
Halpern, ME
中科院分区：
文献类型：
--
作者：
Brösamle, C;Halpern, ME
髓鞘形成是神经胶质细胞包裹轴突并使轴突电绝缘的过程，已被深入研究。然而，关于髓鞘形成是如何调节的，或者髓鞘形成细胞如何与神经元交流的知识仍然不完整。作为这些过程的遗传分析的前奏，我们已经确定了斑马鱼的直系同源基因编码的主要髓鞘蛋白质和髓鞘形成的特点在幼虫斑马鱼。在受精后2天（dpf）检测对应于蛋白脂质蛋白（PLP/DM 20）、髓磷脂蛋白零（PO）和髓磷脂碱性蛋白（MBP）的基因的表达，首先在腹侧后脑中，接近中线。在接下来的8天中，表达扩散到中脑和视神经的吻侧，并向脊髓的尾侧。DM 20仅在CNS中表达，而MBP转录物在CNS和侧线的许旺细胞、颅神经和脊髓运动神经中均检测到。与其最接近的同源物鳟鱼IP 1不同，斑马鱼PO转录物仅限于CNS。超微结构上，髓鞘基因的表达与髓鞘形成相关，虽然髓鞘形成表现出时间滞后。有髓鞘的轴突首先在4 dpf在腹侧后脑中被检测到，在那里它们被神经胶质细胞的突起松散地包裹。到7 dpf时，在同一区域观察到成束的重髓鞘轴突。侧线和视神经的轴突也被致密的髓鞘包围。基因表达模式的保守性和有髓鞘轴突的早期出现，支持使用斑马鱼通过遗传方法来解剖髓鞘形成的过程。
Myelination, the process by which glial cells ensheath and electrically insulate axons, has been investigated intensely. Nevertheless, knowledge of how myelination is regulated or how myelinating cells communicate with neurons is still incomplete. As a prelude to genetic analyses of these processes, we have identified zebrafish orthologues of genes encoding major myelin proteins and have characterized myelination in the larval zebrafish. Expression of genes corresponding to proteolipid protein (PLP/DM20), myelin protein zero (PO), and myelin basic protein (MBP) is detected at 2 days postfertilization (dpf), first in the ventral hindbrain, close to the midline. During the next 8 days, expression spreads rostrally to the midbrain and optic nerve, and caudally to the spinal cord. DM20 is expressed in the CNS only, while MBP transcripts are detected both in the CNS and in Schwann cells of the lateral line, cranial nerves, and spinal motor nerves. Unlike its closest homologue, trout IP1, zebrafish PO transcripts were restricted to the CNS. Ultrastructurally, the expression of myelin genes correlated well with myelination, although myelination showed a temporal lag. Myelinated axons were first detected at 4 dpf in the ventral hindbrain, where they were loosely wrapped by processes of glia cells. By 7 dpf, bundles of heavily myelinated axons were observed in the same region. Axons in the lateral line and optic nerves were also surrounded by compact myelin. Conservation in gene expression patterns and the early appearance of myelinated axons, support using the zebrafish to dissect the process of myelination by a genetic approach.