TRANSCRIPTION FACTORS IN CONTROL OF BRAIN DEVELOPMENT

本子项目是利用由NIH/NCRR资助的中心赠款提供的资源的众多研究子项目之一。子项目和研究者（PI）可能已经从另一个NIH来源获得了主要资金，因此可以在其他CRISP条目中表示。列出的机构是中心的，不一定是研究者的机构。我们目前正在研究发育和成熟神经系统中作为转录调节因子的dna结合因子，特别是po -domain因子Brn-3.0及其相关分子。Brn-3.0的表达模式，在我们之前的工作中被广泛描述，表明在中枢神经系统和外周感觉系统中特定神经元的终端分化和维持中起作用。我们发现Brn-3.0在背神经管中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短暂表达的转录因子不同，Brn-3.0在整个生命过程中都是特定神经元的特征。这部分是由于最近发现的brn-3.0基因组位点的自调节元件，通过这些元件，brn-3.0可以强烈增强其自身的转录。靶向破坏小鼠Brn-3.0可导致新生儿死亡，感觉神经节和部分中枢神经系统核中表达该因子的神经元丢失。这种神经元损失的一个模型是Brn-3.0（-/-）神经元对生存所必需的神经营养因子的反应失败。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PNS和特定CNS神经元的Brn-3.0表达的独立增强子区域。2)利用表达Brn-3.0感觉增强剂控制下的标记基因的小鼠，检测神经发育关键调节因子缺失小鼠的神经元发育，包括Brn-3.0本身，以及选定的神经营养因子及其受体。3)探讨Brn-3.0调控PNS和cns特异性表达的分子机制。4)通过Brn-3.0位点的同源重组，将轴突标记物tau-bgal靶向表达到Brn-3.0神经元上5)利用Cre-recombinase靶向周围神经系统，然后通过loxp介导切除Brn-3.0编码序列，产生具有pns特异性Brn-3.0表达缺陷的小鼠。这使得Brn-3.0在中枢神经系统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三维共聚焦体积进行统计分析。这些研究将促进我们对具有遗传或发育成分的神经和行为疾病的理解。

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.