Ruiz i Altaba A
Developmental Genetics Program, Skirball Institute of Biomolecular Medicine, New York, USA.
Int J Dev Biol. 1996 Dec;40(6):1081-8.
Pattern formation in the vertebrate ventral neural tube has been proposed to depend on the ability of notochord-derived signals to induce the differentiation of distinct cell types in a distance-dependent manner. To determine whether the distribution of early differentiating cell types in the ventral neural tube is consistent with the operation of such a mechanism in vivo, the early localization of Isl-1/2+ motor neurons in relation to HNF-3 beta+ floor plate cells has been investigated. In the most immature regions of the caudal spinal cord of early rat and chick embryos, an initial mixed distribution of cell types was detected that develops into a distribution characteristic of the final embryonic pattern where different cell types are found at distinct locations. In addition, a number of cells that coexpress both markers are detected within the floor plate. At later stages, coexpression is also detected in the hindbrain in the boundary region between HNF-3 beta+ ventricular cells and Isl-1/2+ motor neurons. The mixed distribution of early differentiating cells expressing HNF-3 beta and Isl-1/2 and the coexpression of these markers in single cells within the floor plate suggest that secondary cellular interactions are important in the generation of the final embryonic pattern of the neural tube.
脊椎动物腹侧神经管中的模式形成被认为取决于脊索衍生信号以距离依赖方式诱导不同细胞类型分化的能力。为了确定腹侧神经管中早期分化细胞类型的分布是否与体内这种机制的运作一致，研究了Isl-1/2+运动神经元相对于HNF-3β+底板细胞的早期定位。在早期大鼠和鸡胚胎的尾脊髓最不成熟区域，检测到细胞类型的初始混合分布，这种分布发展为最终胚胎模式的特征分布，不同细胞类型位于不同位置。此外，在底板内检测到一些同时表达两种标记物的细胞。在后期阶段，在HNF-3β+室管膜细胞和Isl-1/2+运动神经元之间的边界区域的后脑也检测到共表达。表达HNF-3β和Isl-1/2的早期分化细胞的混合分布以及这些标记物在底板内单个细胞中的共表达表明，二次细胞间相互作用在神经管最终胚胎模式的产生中很重要。
