Lomvardas Stavros, Barnea Gilad, Pisapia David J, Mendelsohn Monica, Kirkland Jennifer, Axel Richard
Department of Biochemistry and Molecular Biophysics and Howard Hughes Medical Institute, College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA.
Cell. 2006 Jul 28;126(2):403-13. doi: 10.1016/j.cell.2006.06.035.
The expression of a single odorant receptor (OR) gene from a large gene family in individual sensory neurons is an essential feature of the organization and function of the olfactory system. We have used chromosome conformation capture to demonstrate the specific association of an enhancer element, H, on chromosome 14 with multiple OR gene promoters on different chromosomes. DNA and RNA fluorescence in situ hybridization (FISH) experiments allow us to visualize the colocalization of the H enhancer with the single OR allele that is transcribed in a sensory neuron. In transgenic mice bearing additional H elements, sensory neurons that express OR pseudogenes also express a second functional receptor. These data suggest a model of receptor choice in which a single trans-acting enhancer element may allow the stochastic activation of only one OR allele in an olfactory sensory neuron.
单个嗅觉受体（OR）基因在大基因家族中于单个感觉神经元中的表达是嗅觉系统组织和功能的一个基本特征。我们利用染色体构象捕获技术证明了14号染色体上的一个增强子元件H与不同染色体上的多个OR基因启动子存在特异性关联。DNA和RNA荧光原位杂交（FISH）实验使我们能够观察到H增强子与在感觉神经元中被转录的单个OR等位基因的共定位。在携带额外H元件的转基因小鼠中，表达OR假基因的感觉神经元也表达第二种功能性受体。这些数据提示了一种受体选择模型，即单个反式作用增强子元件可能允许在嗅觉感觉神经元中仅随机激活一个OR等位基因。
