DIFFERENTIAL EXPRESSION OF ODORANT BINDING PROTEINS

菜蛾的三种同源气味结合蛋白(OBP) SextA在嗅神经细胞上皮细胞中唯一表达； 不同的OBP在神经元的不同区域表达 上皮组织和OBP的表达是由昆虫的下降诱导的 类固醇激素20-羟基蜕皮激素。差异表达的证据 来自生化和组织学研究。类固醇的证据 调控来自组织培养研究。三者的互补DNA OBP已经被克隆和测序，并正在进行中。这些实验 在本申请中提出的审查监管机制 解释OBP的差异表达和类固醇调节 基因。 嗅觉器官的发育是以一种循序渐进的方式进行的 至少有三个层次的空间组织：嗅觉 器官包含神经元和非神经元上皮域； 神经元上皮被细分为包含不同亚群的区域 嗅觉神经元；具有相同表型的神经元均匀分布 在他们的领域内，但被认为汇聚到一个表型 大脑中已确定的位置。在RAT和 昆虫；这种组织的基础机制可能高度 在不同的动物群体中保存。六分枝杆菌的表达 OBPS反映了这一组织。M.sexta OBP代表了简单和 可访问的工具，用于识别和控制空间和 嗅觉发育过程中的时间调控基因表达 器官和嗅神经细胞上皮细胞。 提出了四个具体目标：(L)细胞的组织学分析 和亚细胞分布；(2)分离， 一株六分枝杆菌三个OBP基因的序列测定和特征分析 已有的基因组文库；(3)可能的DNA鉴定 OBP基因中负责 差异表达；(4)分子水平鉴定 类固醇对OBP基因表达的调控及可能DNA的鉴定 调节序列对类固醇敏感。

The three homologous Odorant Binding Proteins (OBPs) of the moth Manduca sexta are uniquely expressed in the olfactory neuronal epithelium; the respective OBPs are expressed in different domains of the neuronal epithelium and OBP expression is induced by a decline in the insect steroid hormone 20-hydroxy ecdysone. Evidence for differential expression is from biochemical and histological studies. Evidence for steroid regulation is from tissue culture studies. Complementary DNAs of all three OBPs have been cloned and sequenced and are in hand. The experiments proposed in this application examine the regulatory mechanisms that account for differential expression and steroid regulation of the OBP genes. Development of the olfactory organ occurs in a progressive manner to form a tissue with at least three levels of spatial organization: the olfactory organ contains domains of neuronal and non-neuronal epithelium; the neuronal epithelium is subdivided into domains containing distinct subsets of olfactory neurons; neurons of the same phenotype are evenly distributed within their domain but are thought to converge onto a phenotypically defined site in the brain. This organization is observed in both rat and insect; the mechanisms underlying this organization may be highly conserved among different animal groups. The expression of the M. sexta OBPs reflects this organization. The M. sexta OBPs represent simple and accessible tools for identifying and mechanisms controlling spatially and temporally regulated gene expression during development of the olfactory organ and the olfactory neuronal epithelium. Four specific aims are proposed: (l) histological analysis of the cellular and subcellular distributions of the three M. sexta OBPs; (2) isolation, sequencing and characterization of the three OBP genes from a M. sexta genomic library that is in hand; (3) identification of possible DNA regulatory sequences in the OBP genes that are responsible for differential expression; (4) identification of the molecular level of steroid regulation of OBP expression and identification of possible DNA regulatory sequences sensitive to steroid.