SYNAPTIC CONNECTIVITY IN CENTRAL BRAIN

这个建议的总体目标是表征中枢中间神经元之间突触建立和调节的分子机制。我们将致力于实现这一广泛的目标，通过（1）进一步表征果蝇POU结构域转录调节因子Acj 6的功能及其在中枢建立正确突触连接中的作用，（2）鉴定突触形成期间Acj 6调节的通路的其他组分，以及（3）表征氨基末端Acj 6 POUIV盒在调节Acj 6功能中的作用。 这项建议的具体内容如下：（1）通过完成对acj 6突变表型的增强子和抑制子的遗传筛选来鉴定由Acj 6调节的途径的其它组分，（2）通过产生Acj 6神经元特异性表达转座子来进一步表征突触连接中的acj 6突变缺陷，所述转座子既用作细胞特异性标记物又用于错误表达实验，（3）表征由氨基末端POUIV盒的选择性剪接产生的Acj 6同种型的神经元特异性表达;和（4）完成与Acj 6 POUIV盒相互作用的异源蛋白的酵母双杂交筛选。 突触发生的过程需要精确的初始选择正确的突触伙伴和随后的终端过程和连接的细化。 这种突触选择、细化、加强和/或消除的过程被认为对于学习和记忆形成是重要的，并且可能是许多神经病理学的根源。 果蝇（Drosophila melanogaster）突触功能的遗传学分析对我们了解学习和记忆机制做出了重大贡献。 在初步的研究中，我们已经表明，果蝇转录调节因子，Acj 6，是必不可少的终端轴突分支和突触在中央interneurons的一个子集的调节。 在过去的几年中，转录因子相互作用的显着的进化保守性已经证明了详细表征生物体（如果蝇）中的发育调控机制的价值，这些机制可以更容易地通过实验进行操纵。 从分析果蝇中Acj 6蛋白所起的基本发育作用中获得的信息可以外推到高等生物中，以更好地理解突触连接和某些发育异常中涉及的类似过程。

The overall goal of this proposal is to characterize the molecular mechanisms by which synapses between central interneurons are established and modulated. We will work toward that broad goal by (1) further characterizing the function of the Drosophila POU domain transcriptional regulator, Acj6, and its role in establishing correct synaptic connections in the central brain, (2) identifying other components of the pathway(s) regulated by Acj6 during synapse formation and (3) characterizing the role of the amino terminal Acj6 POUIV box in regulating Acj6 function. The specific alms of this proposal are: (1) to identify other components of the pathway(s) regulated by Acj6 through completion of a genetic screen for enhancers and suppressors of the acj6 mutant phenotype, (2) to further characterize the acj6 mutant defects in synaptic connectivity by generating Acj6 neuron-specific expression transposons for use both as cell-specific markers and for misexpression experiments, (3) to characterize the neuron-specific expression of Acj6 isoforms resulting from alternative splicing of the amino terminal POUIV box; and (4) to complete a yeast two-hybrid screen for heterologous proteins interacting with the Acj6 POUIV box. The process of synaptogenesis requires precise initial selection of the correct synaptic partners and subsequent refinement of terminal processes and connections. This process of synaptic selection, refinement, strengthening and/or elimination is thought to be important for learning and memory formation and may lie at the root of a number of neuropathologies. Genetic analysis of synaptic function in the fruit fly, Drosophila melanogaster, has contributed significantly to our knowledge of learning and memory mechanisms. In preliminary studies, we have shown that the Drosophila transcriptional regulator, Acj6, is essential for regulation of terminal axon branching and synaptogenesis in a subset of central interneurons. The significant evolutionary conservation of transcription factor interactions shown over the past several years has demonstrated the value of detailed characterization of developmental regulatory mechanisms in an organism such as Drosophila which can be more readily manipulated experimentally. Information gained from an analysis of the fundamental developmental roles played by the Acj6 protein in Drosophila can be extrapolated to higher organisms to better understand analogous processes involved in synaptic connectivity and certain developmental abnormalities.