Gobron S, Creveaux I, Meiniel R, Didier R, Dastugue B, Meiniel A
Unité 384, Institut National de la Santé et de la Recherche Médicale, and Laboratiore de Biochimie Médicale, Faculté de Médecine, Clermont-Ferrand, France.
Neuroscience. 1999 Jan;88(2):655-64. doi: 10.1016/s0306-4522(98)00252-8.
Bovine SCO-spondin was shown to be a brain-secreted glycoprotein specifically expressed in the subcommissural organ, an ependymal differentiation located in the roof of the Sylvian aqueduct. Also, SCO-spondin makes part of Reissner's fiber, a phylogenetically and ontogenetically conserved structure present in the central canal of the spinal cord of chordates. This secretion is a large multidomain protein probably involved in axonal growth and/or guidance. As Reissner's fiber is highly conserved in the chordate central nervous system, we sought genes orthologous to the bovine SCO-spondin gene by Southern blot analysis in several members of the chordate phylum: urochordates, cephalochordates, cyclostomes, and lower and higher vertebrates, including humans. In addition, conserved glycoproteins present in the subcommissural organ and Reissner's fiber were revealed by immunohistochemistry using antibodies raised against bovine Reissner's fiber. Variation in the sites of Reissner's fiber production according to chordate subphylum, presence of this structure in the spinal cord, and conservation of the SCO-spondin gene are discussed in the context of chordate central nervous system development. These results indicate that SCO-spondin is an ancient ependymal secretion, making part of Reissner's fiber, that may have had an important function during the evolution of the central nervous system in chordates, including that of the spinal cord.
牛SCO-spondin被证明是一种脑分泌的糖蛋白，在连合下器官中特异性表达，连合下器官是位于中脑导水管顶部的一种室管膜分化结构。此外，SCO-spondin是雷斯纳纤维的组成部分，雷斯纳纤维是一种在脊索动物脊髓中央管中存在的系统发育和个体发育上保守的结构。这种分泌产物是一种大型多结构域蛋白，可能参与轴突生长和/或导向。由于雷斯纳纤维在脊索动物中枢神经系统中高度保守，我们通过Southern印迹分析在脊索动物门的几个成员中寻找与牛SCO-spondin基因同源的基因：尾索动物、头索动物、圆口纲动物以及包括人类在内的低等和高等脊椎动物。此外，使用针对牛雷斯纳纤维产生的抗体通过免疫组织化学揭示了连合下器官和雷斯纳纤维中存在的保守糖蛋白。根据脊索动物亚门讨论了雷斯纳纤维产生部位的变化、该结构在脊髓中的存在以及SCO-spondin基因的保守性，这些讨论是在脊索动物中枢神经系统发育的背景下进行的。这些结果表明，SCO-spondin是一种古老的室管膜分泌产物，是雷斯纳纤维的组成部分，在脊索动物包括脊髓的中枢神经系统进化过程中可能具有重要功能。
