Mutually Exclusive Odorant Receptor Regulation

描述（由申请人提供）：基因组是编码生物体遗传部分和程序的主要发育工具。随着许多基因组测序的完成，在寻求理解基因型和表型之间的关系的下一个伟大的前沿是破译基因组信息是如何调节的。这一前沿包括两个基本属性：基因组中的"硬连线"调控代码，它指定了基因表达的空间和时间模式;表观遗传影响，它指定了基因组响应的生物背景。该提案研究了一个复杂的气味受体（OR）基因调控系统，该系统可能揭示基因组的新遗传和表观遗传特性，从而为转录调控如何在全基因组范围内协调提供额外的见解。使用来自前神经元祖细胞的细胞系，我们的实验将提供见解的确定性和随机性的基础上相互排斥的OR表达过程中的嗅觉感觉神经元（OSN）的发展。具体来说，我们将描述OSN祖细胞中受限的OR表达潜力，确定单一OR选择是否利用迭代调节机制，阐明OR协同调节的表观遗传贡献，并研究OR RNA核定位的生物学意义。从广义上讲，这些研究将有助于我们了解基因组的结构组织和“组蛋白密码”，因为它涉及基因协同调节和细胞分化。OSN细胞培养系统的开发和表征应该对神经科学界具有深远的实用性，特别是考虑到嗅觉神经元是哺乳动物中唯一已知的能够在生物体的整个生命中再生的中枢神经元类型之一。对表观遗传调控的研究对医学界也有深远的影响，因为与印记相关的疾病（例如，Beckwith-Wiedemann综合征）、致癌转化和其他遗传性疾病（例如，地中海贫血）与正常染色质状态的扰动有关。总的来说，该项目将利用并进一步开发一个有前途的体外系统，用于研究OR表达和OSN发育，提供OR表观基因组的一些第一批数据，并有助于我们理解我们基因组中固有的基因共调控程序。

DESCRIPTION (provided by applicant): The genome is the cardinal instrument of development that encodes the genetic parts and programs of an organism. With the sequencing of many genomes now complete, a next great frontier in the quest to understand the relationships between genotype and phenotype is to decipher how genome information is regulated. This frontier encompasses two essential attributes: regulatory code "hardwired" in genomes that specify spatial and temporal patterns of gene expression, and epigenetic influences that specify biological context to which a genome responds. This proposal investigates a complex odorant receptor (OR) gene regulatory system that is likely to reveal both novel genetic and epigenetic properties of the genome, and thus provide additional insights into how transcriptional regulation is coordinated genome-wide. Using cell lines derived from pre-neuronal progenitors, our experiments will provide insights into the deterministic and stochastic properties underlying mutually exclusive OR expression during the development of olfactory sensory neurons (OSNs). Specifically, we will characterize restricted OR expression potential in OSN progenitors, determine whether singular OR selection utilizes iterative regulatory mechanisms, elucidate epigenetic contributions to OR co-regulation, and investigate the biological significance of OR RNA nuclear localization. Broadly, these studies will contribute to our knowledge about the structural organization of genomes and the "histone code" as it pertains to gene co- regulation and cell differentiation. The development and characterization of an OSN cell culture system should have far-reaching utility to the neuroscience community, especially considering that olfactory neurons are one of the only known central neuron types in mammals that are capable of regeneration throughout the life of an organism. Research on epigenetic regulation also has far-reaching implications to the medical community, since imprinting-related diseases (e.g., Beckwith-Wiedemann syndrome), oncogenic transformation, and other genetic disorders (e.g., Thalassemia) are associated with perturbation of normal chromatin states. In total, this project will utilize and further develop a promising in vitro system for studying OR expression and OSN development, provide some of the first data on the OR epigenome, and contribute to our understanding of gene co-regulatory programs inherent in our genome.