MOLECULAR BIOLOGY OF OLFACTORY RECEPTOR GENES

了解大脑的发育和功能需要 解释巨细胞病毒产生的机制 具有唯一身份的神经元的数量。此外，数量众多的 不同的神经元最终必须以特定的方式相互连接 模式。嗅觉系统提供了一个很好的模型系统 研究这些问题是因为1000个嗅觉受体基因 作为功能不同的神经元亚群的分子标记。 我们的初步研究表明，控制的层次结构在 嗅觉受体基因家族，这样一个给定的嗅觉神经元 只表达上千种可能基因中的一种。一种涉及的机制 调节嗅觉受体基因表达的等位基因失活 (只表达两个等位基因中的一个)。基于这些研究，目标是 是为了阐明嗅觉感受器的潜在机制 基因调控与等位基因失活： 1.确定DNA重排是否在选择哪一个中起作用 表达嗅觉受体。 2.确定参与调节嗅觉的顺式作用DNA元件 受体基因。 3.进一步确定等位基因失活的特征并鉴定其 潜在的分子机制。 重排的潜在作用将在分子研究中得到解决。 在细胞系中表达特定受体的纯化嗅觉神经元 来源于嗅神经上皮。一旦细胞选择了 一个给定的受体是分离出来的，基因组DNA将被分析以寻找 DNA重排。与重新安排的问题无关，我们希望 来理解控制的要素。我们将使用人工酵母 染色体(YAC)来定位编码嗅觉受体的基因座。独联体 参与受体基因选择的作用DNA元件将在 转基因小鼠实验。确定等位基因特征的实验 失活将涉及对转录和DNA复制的分析 细胞系和转基因小鼠。 这些研究将阐明基因调控导致 为大脑中神经元多样性的非凡一代，并将 对了解脑功能障碍有一定价值。此外， 哺乳动物的嗅觉神经元在生物体的整个生命过程中都会再生。 因此，了解这些神经元使用的基因表达机制是 对理解神经发育障碍有特别的相关性。

Understanding the development and function of the brain requires the elucidation of mechanisms underlying the generation of an extremely large number of neurons with unique identities. Moreover, the multitude of distinct neurons ultimately must connect to each other in specific patterns. The olfactory system provides an excellent model system for investigating these questions because the 1,000 olfactory receptor genes serve as molecular markers for functionally distinct subsets of neurons. Our preliminary studies indicate that a hierarchy of controls operates on the family of olfactory receptor genes, such that a given olfactory neuron expresses only one of the thousand possible genes. One mechanism involved in regulating olfactory receptor gene expression is allelic inactivation (only one of two alleles is expressed). Based on these studies, the aims of this proposal are to elucidate mechanisms underlying olfactory receptor gene regulation and allelic inactivation: 1. To determine if DNA rearrangement plays a role in the choice of which olfactory receptor is expressed. 2. To define the cis-acting DNA elements involved in regulating olfactory receptor genes. 3. To further characterize allelic inactivation and to identify its underlying molecular mechanisms. The potential role of rearrangement will be addressed in molecular studies of purified olfactory neurons expressing a given receptor and in cell lines derived from the olfactory neuroepithelium. Once cells which have chosen a given receptor are isolated, the genomic DNA will be analyzed to look for DNA rearrangement. Independent of the question of rearrangement, we wish to understand elements of control. We will use yeast artificial chromosomes (YACs) to map the loci encoding olfactory receptors. Cis acting DNA elements involved in receptor gene choice will be defined in transgenic mouse experiments. Experiments to characterize allelic inactivation will involve analyses of transcription and DNA replication in cell lines and transgenic mice. These studies will elucidate mechanisms through which gene regulation leads to the remarkable generation of neuronal diversity in the brain, and will be of value in understanding disorders of brain function. Moreover, mammalian olfactory neurons regenerate throughout the life of the organism. Thus, understanding the gene expression mechanisms used by these neurons is of particular relevance to understanding neurodevelopmental disorders.