Retinoid Signaling in Neural Patterning in Zebrafish

描述(申请人的描述)：神经系统检查结果的缺陷 不受控制神经发育的正常机制的破坏。因此， 要了解遗传性神经疾病的基础需要 了解控制花纹的胚胎分子和遗传过程 神经前体的形成。其中包括组织间的相互作用 建立神经管的主轴，它的分化为 不同的神经元类型，以及它们之间的相互联系，形成了一种功能 神经网络。这项建议使用遗传学和 斑马鱼作为模型的胚胎学优势。斑马鱼胚胎形成一种 简单的神经系统，在那里与人脑和 脊髓是可识别的，许多形成这些区域的基因 一直保存在鱼和人类之间。据认为，一名少校 神经系统前-后模式的成分是维甲酸 酸(RA)，一种引导神经元发育模式的信号 身体轴。外源性RA截断前部发育，并已被证明 会导致人类严重的神经和颅面缺陷。实验是 建议使用斑马鱼突变体来分析这一信号的作用 视黄醛脱氢酶(RALDH2)，一种在体内合成RA的酶 胚胎，以及特定的RA拮抗剂或显性阴性形式 受体(RAR)。目标1是描述基因表达缺陷的特征。 RALDH2突变，并与RAR干扰的影响进行比较，以确定 类风湿性关节炎及其可能的靶基因的需求程度 神经系统。目标2是分析斑马鱼初级种群的简单模式 神经元，结合生活中神经发育的实时成像 使用转基因方法的胚胎，在这种方法中，发育中的神经元表达一个 RALDH2突变体和RAR基因突变胚胎中的荧光标记 发信号。这将阐明类风湿关节炎影响的总体程度 身体轴及其在几乎每一个人的行为和命运中的角色 系统中的神经元。转基因生物的光学清晰度和可用性 斑马鱼使其特别适合于这项研究。目标3侧重于一个特定的 中胚层和发育中的神经之间需要类风湿因子的组织相互作用 试管，通过使用细胞移植在RALDH2突变体中获得生化 神经模式的基础。

DESCRIPTION (Applicant's Description): Defects of the nervous system result from disruptions of the normal mechanisms that control neural development. Thus understanding the basis for inherited neurological disorders requires a knowledge of the embryonic molecular and genetic processes that control pattern formation in neural precursors. These include the tissue interactions that establish the primary axes of the neural tube, its differentiation into different neuronal types, and their interconnections to form a functional neural network. This proposal examines these issues using the genetics and embryological advantages of the zebrafish as a model. Zebrafish embryos form a simple nervous system, where homologies with regions of the human brain and spinal cord are recognizable and many of the genes that pattern these regions have been conserved between fish and humans. It is thought that a major component of anterior-posterior patterning of the nervous system is retinoic acid (RA), a signal that directs patterns of neuronal development along the body axis. Exogenous RA truncates anterior development and has been shown to cause severe neural and craniofacial defects in humans. Experiments are proposed to dissect the role of this signal using a zebrafish mutant in retinaldehyde dehydrogenase (RALDH2), an enzyme that synthesizes RA in the embryo, as well as specific antagonists or dominant negative forms of RA receptors (RARs). Aim 1 is to characterize defects in gene expression in the RALDH2 mutant and compare them with the effects of RAR disruption, to define the extent of the requirement for RA and its possible target genes in the nervous system. Aim 2 is to analyze the simple pattern of zebrafish primary neurons, combined with real time imaging of neural development in living embryos using a transgenic approach in which developing neurons express a fluorescent marker, both in RALDH2 mutants and in embryos with disrupted RAR signalling. This will elucidate the overall extent of the influence of RA along the body axis and its roles in the behaviors and fates of virtually every neuron in the system. The optical clarity and availability of transgenic zebrafish make it uniquely suited for this study. Aim 3 focuses on a particular tissue interaction that requires RA, between the mesoderm and developing neural tube, by using cell transplantation in RALDH2 mutants to get to the biochemical basis for neural patterning.