DNA Recombination/Repair Mechanisms in Memory

描述(申请人提供)：大脑是否拥有一种机制来产生支持记忆存储的遗传多样性？这项提议旨在测试DNA重组/修复机制在大脑记忆存储中发挥特定作用的想法。基因重排可以在大脑中作为一种机制来产生依赖经验的蛋白质多样性，这可能有助于存储一生中获得的信息。DNA重组可能作为转录上游的一种机制，调节一组对长期记忆存储至关重要的特定基因的表达和功能。因此，记忆中基因调控的表观遗传、转录和重组机制不是相互排斥的，而是很可能相互补充的。在这一点上，与大脑中基因重组和记忆形成的想法相关的最耐人寻味的问题是，在神经元中调节这一过程的因素是什么，更重要的是，哪些基因受到这种调节以应对学习。在这个提案中，我们关注条件性味觉厌恶(CTA)的巩固机制，CTA是一种行为范式，其特征是许多动物在经历不愉快或有害的躯体(内脏)反应后，能够学习避免某些物质。目的1研究杏仁核DNA重组机制在大鼠CTA巩固中的作用，通过基因敲除的方法，针对可能的重组效应酶、Fen-1和DNA连接酶IV的功能。目的2研究杏仁核DNA重组靶基因的重排，如原钙粘蛋白p9。特别是，实验将确定原钙粘附素09基因是否在杏仁核神经元中经历与CTA相关的基因组重排。总体而言，这些研究将确立DNA重组/修复过程是大脑用来长期存储信息的初始机制的一部分，表征参与这一过程的特定因素的功能，并有助于证明特定的基因靶标在记忆形成过程中经历基因组重排。

DESCRIPTION (provided by applicant): Does the brain possess a mechanism for generating genetic diversity that could support memory storage? This proposal aims to test the idea that DNA recombination/repair mechanisms play a specific part in memory storage in the brain. Gene rearrangements may be used in the brain as a mechanism to generate experience-dependent protein diversity that could contribute to the storage of information acquired throughout a lifetime. DNA recombination may serve as a mechanism upstream of transcription to regulate the expression and function of a specific set of genes important for long-lasting memory storage. Thus, epigenetic, transcriptional, and recombinational mechanisms of gene regulation in memory do not exclude one another, but most likely complement each other. At this point, the most intriguing questions related to the idea of gene recombination and memory formation in the brain are what are the factors that mediate such a process in neurons and, more importantly, what are the genes that are subjected to this kind of regulation in response to learning. In this proposal, we focus on consolidation mechanisms of conditioned taste aversion (CTA), a behavioral paradigm characterized by the ability of many animals to learn to avoid certain substances after experiencing an unpleasant or harmful somatic (visceral) reaction. Aim # 1 of this proposal addresses the role of amygdalar DNA recombination mechanisms in consolidation of CTA in rats by using or gene knockdown approaches, both targeting the function of putative recombination effector enzymes, Flap Structure-Specific Endonuclease-1 (FEN-1) and DNA ligase IV. AIM # 2 examines amygdalar genomic rearrangement of putative DNA recombination target genes, such as protocadherin p9. Particularly, experiments will determine if the protocadherin 09 gene undergoes CTArelated genomic rearrangement in amygdala neurons. Overall, these studies will establish that DNA recombination/repair processes are part of the initial mechanisms utilized by the brain for the long-lasting storage of information, characterize the function of specific factors involved in this processes, and help demonstrate that specific gene targets undergo genomic rearrangement during memory formation.