Mutually Exclusive Odorant Receptor Regulation

描述(申请人提供)：基因组是发育的主要工具，编码有机体的遗传部分和程序。随着许多基因组测序的完成，在寻求了解基因和表型之间的关系方面的下一个重大前沿是破译基因组信息是如何调控的。这一前沿包括两个基本属性：基因组中指定基因表达的空间和时间模式的调控代码，以及指定基因组响应的生物背景的表观遗传影响。这项建议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的遗传和表观遗传属性，从而为转录调控如何在全基因组范围内协调提供更多的见解。利用来自神经前体细胞的细胞系，我们的实验将提供对嗅觉感觉神经元(OSN)发育过程中相互排斥OR表达的确定性和随机性的见解。具体地说，我们将表征OSN前体的限制性OR表达潜力，确定单一OR选择是否利用迭代调节机制，阐明表观遗传学对OR共同调节的贡献，并探讨OR RNA核定位的生物学意义。总的来说，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”，因为它与基因共同调节和细胞分化有关。OSN细胞培养系统的开发和表征对神经科学界应该具有深远的实用价值，特别是考虑到嗅觉神经元是哺乳动物中仅有的几种已知的能够在生物体的整个生命周期中再生的中枢神经元类型之一。表观遗传调控的研究对医学界也具有深远的影响，因为印记相关疾病(例如Beckwith-Wiedemann综合征)、致癌转化和其他遗传疾病(例如地中海贫血)与正常染色质状态的扰动有关。总之，该项目将利用并进一步开发一个有前景的体外系统来研究OR表达和OSN的发育，提供一些关于OR表观基因组的第一批数据，并有助于我们理解我们基因组中固有的基因协同调节程序。

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.