The Zonal Organization of Odorant Receptor Gene Choice in the Main Olfactory Epithelium of the Mouse

Cell Rep. 2020 Mar 24;30(12):4220-4234.e5. doi: 10.1016/j.celrep.2020.02.110.


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.

Keywords: 3D reconstruction; axonal wiring; expression pattern; gene targeting; glomerulus; olfaction; olfactory bulb; olfactory sensory neuron; spatial organization; zone.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Axons / metabolism
  • Gene Expression Regulation
  • Genetic Loci
  • Green Fluorescent Proteins / metabolism
  • Imaging, Three-Dimensional
  • Mice, Inbred C57BL
  • Olfactory Mucosa / innervation
  • Olfactory Mucosa / metabolism*
  • Receptors, Odorant / genetics*


  • Receptors, Odorant
  • Green Fluorescent Proteins