Major Isoform of Zebrafish P0 Is a 23.5 KDa Myelin Glycoprotein Expressed in Selected White Matter Tracts of the Central Nervous System
Major Isoform of Zebrafish P0 Is a 23.5 KDa Myelin Glycoprotein Expressed in Selected White Matter Tracts of the Central Nervous System
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DOI：
10.1002/cne.22587
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发表时间：
2011-06-01
影响因子：
2.5
通讯作者：
Burton, Edward A.
中科院分区：
文献类型：
--
作者：
Bai, Qing;Sun, Ming;Burton, Edward A.
斑马鱼mpz基因编码哺乳动物髓鞘蛋白零的直系同源物，在斑马鱼中枢神经系统（CNS）的少突胶质细胞中表达。推定的基因产物P0除了在致密髓鞘中具有拟议的结构功能外，还涉及促进轴突再生。我们提出了新的斑马鱼P0特异性抗体，并建立了P0是一个23.5 kDa的糖蛋白，含有3 kDa的N-连接的碳水化合物部分。P0定位于髓鞘周围的轴突，但在少突胶质细胞的细胞体或近端过程中没有检测到。许多白色物质束在成年斑马鱼中枢神经系统中的P0，包括传入视觉和嗅觉通路，连合和纵向的大脑，并选择上升和下降的脊髓束的强烈免疫反应。在发育过程中，受精后48小时（hpf），在腹侧后脑的前髓鞘少突胶质细胞中首次检测到P0。72 hpf，短段的纵向取向的P0-免疫反应性髓鞘轴突被认为是在后脑;表达在脊髓，视神经通路，后脑连合，中脑，和周围神经系统。发现mpz转录物是可变剪接的，产生具有可变C-末端的P0同种型。23.5 kDa的亚型是最丰富的中枢神经系统，但其他亚型占主导地位的髓鞘周围的Mauthner轴突。这些数据提供了一个详细的帐户P0的表达，并证明新的P0亚型，这可能有离散的功能特性。P0免疫反应性髓鞘的限制表明，该蛋白质受到严格的细胞内区室化，这可能是通过翻译后机制发生的。神经学比较杂志519：1580-1596，2011。(C)2010 Wiley-Liss，Inc.
The zebrafish mpz gene, encoding the ortholog of mammalian myelin protein zero, is expressed in oligodendrocytes of the zebrafish central nervous system (CNS). The putative gene product, P0, has been implicated in promoting axonal regeneration in addition to its proposed structural functions in compact myelin. We raised novel zebrafish P0-specific antibodies and established that P0 is a 23.5 kDa glycoprotein containing a 3 kDa N-linked carbohydrate moiety. P0 was localized to myelin sheaths surrounding axons, but was not detected in the cell bodies or proximal processes of oligodendrocytes. Many white matter tracts in the adult zebrafish CNS were robustly immunoreactive for P0, including afferent visual and olfactory pathways, commissural and longitudinal tracts of the brain, and selected ascending and descending tracts of the spinal cord. P0 was first detected during development in premyelinating oligodendrocytes of the ventral hindbrain at 48 hours postfertilization (hpf). By 72 hpf, short segments of longitudinally oriented P0-immunoreactive myelinating axons were seen in the hindbrain; expression in the spinal cord, optic pathways, hindbrain commissures, midbrain, and peripheral nervous system followed. The mpz transcript was found to be alternatively spliced, giving rise to P0 isoforms with alternative C-termini. The 23.5 kDa isoform was most abundant in the CNS, but other isoforms predominated in the myelin sheath surrounding the Mauthner axon. These data provide a detailed account of P0 expression and demonstrate novel P0 isoforms, which may have discrete functional properties. The restriction of P0 immunoreactivity to myelin sheaths indicates that the protein is subject to stringent intracellular compartmentalization, which likely occurs through posttranslational mechanisms. J. Comp. Neurol. 519: 1580-1596, 2011. (C) 2010 Wiley-Liss, Inc.