Blumberg B, Bolado J, Moreno T A, Kintner C, Evans R M, Papalopulu N
Gene Expression Laboratory, Salk Institute, La Jolla, CA 92037, USA.
Development. 1997 Jan;124(2):373-9. doi: 10.1242/dev.124.2.373.
The vertebrate central nervous system (CNS) is induced by signals emanating from the dorsal mesoderm, or organizer, that divert the ectoderm away from an epidermal and towards a neural fate. Additional signals from the organizer pattern the neural ectoderm along the anteroposterior axis. We devised highly specific methods utilizing constitutively active or dominant negative receptors to evaluate the role of retinoids in neural patterning. Microinjection of these reagents either augments or reduces retinoid signaling in specific regions of the embryo. We show that increased receptor activity suppresses anterior neural structures while dominant negative receptors lead to anterior enhancement. Similarly, microinjection of the dominant negative receptor leads to the loss of posterior marker genes. We demonstrate that retinoid receptors comprise a critical component in neural posteriorization and are required for proper neuronal differentiation. These results support a quantitative role for retinoid signaling in regionalization of the CNS.
脊椎动物的中枢神经系统（CNS）由背侧中胚层或组织者发出的信号诱导产生，这些信号使外胚层偏离表皮命运而转向神经命运。来自组织者的其他信号沿前后轴对神经外胚层进行模式化。我们设计了高度特异性的方法，利用组成型激活或显性负性受体来评估视黄酸在神经模式形成中的作用。显微注射这些试剂可增强或降低胚胎特定区域的视黄酸信号传导。我们发现，受体活性增加会抑制前神经结构，而显性负性受体则会导致前部增强。同样，显微注射显性负性受体导致后部标记基因缺失。我们证明视黄酸受体是神经后部化的关键组成部分，是神经元正常分化所必需的。这些结果支持视黄酸信号在中枢神经系统区域化中的定量作用。
