Odorant receptor diversity and patterned gene expression in the mammalian olfactory epithelium.

The mammalian olfactory system is capable of discriminating a vast array of structurally diverse odors. We have identified a novel multigene family whose unusual size and diversity suggest that odor discrimination may rely heavily on the existence of many hundreds of different types of odorant receptors which are differentially expressed by olfactory sensory neurons in the nasal cavity. We have found that the members of this family are segregated in their expression into a series of distinct, and highly specified, zones within the olfactory epithelium. Our experiments suggest that the odorant receptor expression zones may provide for an initial organization of sensory information in the nasal cavity which is maintained in the transmission of this information to the olfactory bulb of the brain.