A mature olfactory sensory neuron (OSN) of the main olfactory epithelium (MOE) typically expresses one allele of one odorant receptor (OR) gene. It is widely thought that the great majority of the 1,141 intact mouse OR genes are expressed in one of four MOE zones (or bands or stripes), which are largely non-overlapping. Here, we develop a multiplex method to map, in 3D and MOE-wide, the expression areas of multiple OR genes in individual, non-genetically modified mice by three-color fluorescence in situ hybridization, semi-automated image segmentation, and 3D reconstruction. We classify the expression areas of 68 OR genes into 9 zones. These zones are highly overlapping and strikingly complex when viewed in 3D reconstructions. There could well be more zones. We propose that zones reflect distinct OSN types that are each restricted in their choice to a subset of the OR gene repertoire.

主要嗅觉上皮细胞（MOE）的成熟嗅觉感觉神经元（OSN）通常表达一种气味受体（OR）基因的一个等位基因。人们普遍认为，在完整的1141个小鼠OR基因中，绝大多数是在四个MOE区（或条带或条带）之一中表达的，而这些MOE区基本上是不重叠的。在这里，我们开发了一种多重方法，可通过3色荧光原位定位在3D和MOE范围内的单个或非转基因小鼠中多个OR基因的表达区域杂交，半自动图像分割和3D重建。我们将68个OR基因的表达区域分为9个区域。在3D重建中查看时，这些区域高度重叠且非常复杂。可能会有更多区域。我们建议区域反映不同的OSN类型，每种类型的选择仅限于OR基因库的一个子集。