Zebrafish primary neurons initiate expression of the LIM homeodomain protein Isl-1 at the end of gastrulation.
Zebrafish primary neurons initiate expression of the LIM homeodomain protein Isl-1 at the end of gastrulation.
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DOI：
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发表时间：
1993-06
期刊：
影响因子：
4.6
通讯作者：
V. Korzh;T. Edlund;S. Thor
中科院分区：
文献类型：
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作者：
V. Korzh;T. Edlund;S. Thor
ISL-1是鸡脊髓运动神经元发育的最早标记物，受底板和脊索的诱导信号调控。我们现在报道，在斑马鱼中，ISL-1的表达是在神经管形成之前的几个小时，在Rohon-Beard细胞、初级运动神经元、中间神经元和颅神经节中启动的。这种表达在罗洪-比尔德细胞和初级运动神经元中同时启动，在推测的第一体节的轴向水平上。表达ISL-1的运动神经元出现在腹中线的两侧，而中间神经元和Rohon-Beard细胞在生发屏障边缘开始表达。在分化的脊索形成之前，ISL-1在这些细胞中开始表达。受精后24小时，ISL-1在不同功能级别的原代神经元中均有表达。这种同源结构域蛋白在初级神经元中的选择性表达意味着这些神经元共享一个共同的早期发育程序，它们已经进化并被选为一个协调系统。初级神经元的功能之一是发送长轴突，这是斑马鱼胚胎中主轴突束的先驱。ISL-1在原代神经元的先锋表型表达中具有进化保守的功能。
Isl-1 has previously been established as the earliest marker of developing chicken spinal motor neurons where it is regulated by inductive signals from the floorplate and notochord. We now report that, in zebrafish, the expression of Isl-1 is initiated in Rohon-Beard cells, primary motor neurons, interneurons and cranial ganglia, hours before the neural tube itself is formed. The expression is initiated simultaneously in the Rohon-Beard cells and the primary motor neurons, at the axial level of the presumptive first somite. The Isl-1-expressing motor neurons appear on either side of the ventral midline whereas the interneurons and Rohon-Beard cells initiate expression while located at the edge of the germinal shield. Isl-1 expression is initiated in these cells before the formation of a differentiated notochord. Isl-1 is expressed in the various functional classes of primary neurons at 24 hours postfertilization. This selective expression of a homeodomain protein in the primary neurons implies that these neurons share a common program of early development and that they have evolved and been selected for as a coordinated system. One of the functions of the primary neurons is to send long axons which pioneer the major axon tracts in the zebrafish embryo. An evolutionary conserved functional role for Isl-1 in the expression of the pioneering phenotype of the primary neurons is suggested.