TRANSCRIPTION FACTORS IN CONTROL OF BRAIN DEVELOPMENT

这个子项目是利用由NIH/NCRR资助的中心拨款提供的资源的许多研究子项目之一。子项目和调查员(PI)可能从另一个NIH来源获得了主要资金，因此可能会出现在其他CRISE条目中。列出的机构是针对中心的，而不一定是针对调查员的机构。我们目前正在研究在发育和成熟的神经系统中作为转录调节因子的DNA结合因子，特别是POU结构域因子BRN-3.0和相关分子。BRN-3.0的表达模式在我们之前的工作中得到了广泛的描述，表明在中枢神经系统和外周感觉系统中特定神经元的终末分化和维持中发挥了作用。我们发现，BRN-3.0在背侧神经管的初始表达模式受到腹侧信号SHH的负调控。与许多在发育过程中瞬时表达的转录因子不同，BRN-3.0在整个生命过程中表征了特定的神经元。这在一定程度上是由于最近在BRN-3.0基因组座位上发现了自我调节元件，通过这些元件，BRN-3.0可以强烈地增强自身的转录。在小鼠中靶向破坏BRN-3.0会导致新生儿死亡，感觉神经节和一些表达该因子的中枢神经系统核中的神经元丢失。这种神经元丢失的一个模型是BRN-3.0(-/-)神经元对生存所需的神经营养素反应失败。目前尚不清楚新生儿死亡是由于BRN-3.0的中枢或外周功能丧失，还是两者兼而有之。我们的目标是：1)进一步确定针对感觉三叉神经节和特定中枢神经系统神经元表达BRN-3.0的独立增强子区域。2)利用在BRN-3.0感觉增强剂控制下表达标记基因的小鼠，检测缺乏神经发育关键调控因子的小鼠的神经元发育，包括BRN-3.0本身，以及选定的神经营养因子及其受体。3)研究BRN-3.0 PNS和CNS特异性表达调控的分子机制。4)通过BRN-3.0位点的同源重组将轴突标志物tau-BGAL靶向BRN-3.0神经元。5)利用Cre-重组酶靶向外周神经系统，然后通过loxP介导的BRN-3.0编码序列的切除，产生PNS特异性BRN-3.0表达缺陷的小鼠。这使得BRN-3.0在中枢和外周感觉系统中的作用得以区分。我们正在使用NCMIR计算资源对胚胎中双标记荧光蛋白的3D共聚焦体积进行统计分析。这些研究将促进我们对神经和行为疾病的理解，这些疾病有遗传或发育因素。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. We are currently studying DNA-binding factors that serve as transcriptional regulators in the developing and mature nervous system, specifically the POU-domain factor Brn-3.0 and related molecules. The expression pattern of Brn-3.0, described extensively in our previous work, indicates a role in the terminal differentiation and maintenance of specific neurons in the CNS and peripheral sensory system. We showed that the initial pattern of Brn-3.0 expression in the dorsal neural tube is negatively regulated by the ventral signal SHH. Unlike many transcription factors expressed transiently in development, Brn-3.0 characterizes specific neurons throughout life. This is due in part to recently identified autoregulatory elements in brn-3.0 genomic locus through which Brn-3.0 can strongly enhance its own transcription. Targeted disruption of Brn-3.0 in mice results in neonatal death and loss of neurons in the sensory ganglia and some CNS nuclei which express this factor. One model for this neuronal loss is a failure of Brn-3.0 (-/-) neurons to respond to neurotrophins necessary for survival. It is not known whether neonatal death is due to loss of the central or peripheral functions of Brn-3.0, or both. Our goals are to: 1) Further define the independent enhancer regions that target Brn-3.0 expression to the sensory PNS and specific CNS neurons. 2) Use mice expressing marker genes under control of the Brn-3.0 sensory enhancer to examine neuronal development in mice deficient in key regulators of neurodevelopment, including Brn-3.0 itself, and selected neurotrophins and their receptors. 3) Examine the molecular mechanisms of the regulation of PNS- and CNS-specific expression of Brn-3.0. 4) Target expression of an axonal marker, tau-bgal, to Brn-3.0 neurons by homologous recombination at the Brn-3.0 locus 5) Use targeting of Cre-recombinase to the peripheral nervous system, followed by loxP-mediated excision of Brn-3.0 coding sequences, to produce mice with PNS-specific defects in Brn-3.0 expression. This allows the roles of Brn-3.0 in the CNS and peripheral sensory system to be distinguished. We are using the NCMIR computational resources for statistical analysis of 3D confocal volumes of dual labeled fluorescent proteins in embryos. These studies will advance our understanding of neurological and behavioral illnesses that have a genetic or developmental component.