A putative olfactory receptor-encoding gene was cloned from human geno
mic DNA and shown to be expressed by isolation of a full-length cDNA f
rom olfactory tissue. A second cDNA clone was found to encode an olfac
tory receptor pseudogene. The expression of a pseudogene from the olfa
ctory gene repertoire, in neurons which express only a single receptor
type, implies that many neurons will be non-functional.