Comparison of sequence and function of the Oct-6 genes in zebrafish, chicken and mouse
Comparison of sequence and function of the Oct-6 genes in zebrafish, chicken and mouse
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DOI：
10.1016/s0925-4773(98)00067-7
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发表时间：
1998-06-01
影响因子：
2.6
通讯作者：
Meijer, D
中科院分区：
文献类型：
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作者：
Levavasseur, F;Mandemakers, W;Meijer, D
为了检查 Oct-6 基因在雪旺细胞分化中的作用，我们克隆并鉴定了小鼠 Oct-6 基因的鸡和斑马鱼同源物。虽然在 Pit1-Oct1/2-Unc86 (POU) 结构域中高度同源，但序列相似性在该结构域之外受到限制。两个基因都是无内含子的，并且两种蛋白质都缺乏氨基酸重复，而氨基酸重复是哺乳动物 Oct-6 蛋白质的特征。然而，与哺乳动物一样，鸡和斑马鱼 Oct-6 蛋白的氨基末端部分对于含有八聚体的启动子的反式激活至关重要。通过免疫组织化学，我们发现鸡Oct-6蛋白在胚胎晚期坐骨神经鞘雪旺细胞中表达，并在髓鞘形成过程中迅速下调。神经胶质细胞中的表达谱与小鼠和大鼠中的表达谱相同。此外，斑马鱼 Oct-6 同源物在后侧神经中表达，此时其含有活跃的髓鞘形成雪旺细胞。因此，尽管脊椎动物 Oct-6 蛋白的一级序列存在广泛差异，但鸡和斑马鱼 Oct-6 蛋白的表达与 Oct-6 作为髓磷脂原细胞中执行髓鞘化程序的“能力因子”的概念是一致的。 (C) 1998 Elsevier Science Ireland Ltd. 保留所有权利。
To examine the role of the Oct-6 gene in Schwann cell differentiation we have cloned and characterized the chicken and zebrafish homologues of the mouse Oct-6 gene. While highly homologous in the Pit1-Oct1/2-Unc86 (POU) domain, sequence similarities are limited outside this domain. Both genes are intronless and both proteins lack the amino acid repeats that are a characteristic feature of the mammalian Oct-6 proteins. However as in mammals, the aminoterminal parts of the chicken and zebrafish Oct-6 proteins are essential for transactivation of octamer containing promoters. By immunohistochemistry we have found that the chicken Oct-6 protein is expressed in late embryonic ensheathing Schwann cells of the sciatic nerve and is rapidly downregulated when myelination proceeds. This expression profile in glial cells is identical to that in the mouse and rat. Furthermore the zebrafish Oct-6 homolog is expressed in the posterior lateral nerve at a time when it contains actively myelinating Schwann cells. Thus despite extensive primary sequence divergence among the vertebrate Oct-6 proteins, the expression of the chicken and zebrafish Oct-6 proteins is consistent with the notion that Oct-6 functions as a 'competence factor' in promyelin cells to execute the myelination program. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved.