MOLECULAR BIOLOGY OF OCULOMOTOR SYSTEM DEVELOPMENT

描述（由申请人提供）：本研究的长期目标是了解脑干眼神经控制系统的细胞核和回路的分子发育。 本项目的重点是在中脑眼神经复合体（OMC）和后脑三叉神经核（TrN）的眼神经元生产的调节机制。 建议的实验将在鸡胚中进行，鸡胚具有通过电穿孔进行定点转基因的实验优势，并且与其他鸟类共享由具有不同眼外肌靶点的离散亚核组成的高度组织化的OMC。 第一组实验评估同源结构域转录因子在指定眼神经元身份和产生离散OMC亚核中的作用。 这些实验包括CFEOM 2候选基因PHOX 2A的功能的分子解剖。 第二组实验研究了调节中脑祖细胞到眼神经元命运的分子机制，重点是NKX 6和碱性螺旋-环-螺旋转录因子在这些过程中的作用。 第三组实验是基于我们的发现显着的转录因子的异质性内的TrN和OMC亚核。 我们将研究这种异质性的解剖学相关性，专注于这些分子分裂识别运动神经元与不同的目标，在oculopathy植物的具体假设。 对OMC和TrN发育机制的研究可能会深入了解眼神经系统的遗传疾病，最值得注意的是那些如CFEOM的眼神经元的特定池丢失。 更一般地说，了解独特的分子规格的眼细胞类型可能会提出新的治疗策略，包括干细胞为基础的方法，用于治疗的眼障碍，并可能会给洞察力的眼单位的相对电阻一些运动神经元疾病。

DESCRIPTION (provided by applicant): The long-term goal of this research is to understand the molecular development of the nuclei and circuitry of the brainstem oculomotor control system. The focus of this project is on the regulatory mechanisms underlying oculomotor neuron production in the midbrain oculomotor complex (OMC) and the hindbrain trochlear nucleus (TrN). The proposed experiments will be carried out in chick embryos, which have the experimental advantage of site-directed transgenesis by electroporation and which share with other birds a highly organized OMC composed of discrete subnuclei with distinct extraocular muscle targets. The first set of experiments assesses the roles of homeodomain transcription factors in specifying oculomotor neuron identity and generating discrete OMC subnuclei. These experiments include a molecular dissection of the function of the CFEOM2 candidate gene PHOX2A. The second set of experiments investigates the molecular mechanisms that regulate the specification of midbrain progenitor cells to an oculomotor neuron fate, with a focus on the roles of NKX6 and basic helix-loop-helix transcription factors in these processes. The third set of experiments is based on our findings of pronounced transcription factor heterogeneity within the TrN and OMC subnuclei. We will investigate the anatomical correlate of this heterogeneity, focusing on the specific hypothesis that these molecular divisions identify motor neurons with distinct targets in the oculomotor plant. Study of the mechanisms that govern OMC and TrN development may provide insight into genetic diseases of the oculomotor system, most notably those such as CFEOM in which specific pools of oculomotor neurons are lost. More generally, understanding of the unique molecular specification of oculomotor cell types may suggest novel therapeutic strategies, including stem cell-based approaches, for the treatment of oculomotor disorders, and may give insight to the relative resistance of the oculomotor unit to some motor neuron diseases.