Does a unique olfactory genome imply a unique olfactory world?

摘要

Olfaction holds in itself a major mystery: no scientist or perfumer can look at the structure of a novel molecule and predict its odor or smell a novel odor and predict its molecular structure. Many argued that this mystery would be solved following a pivotal study published in 1991, where Linda Buck and Richard Axel identified a family of -1,000 genes that encode seven-transmembrane G protein-coupled olfactory receptors. Subsequent studies found that each receptor subtype was responsive to a small number of different odorants and that each odorant activated a small number of different receptor subtypes, suggesting a combinatorial code for olfaction. Thus, researchers embarked on a quest to de-orphan olfactory receptor subtypes by expressing each of them in vitro, bombarding them with panels of odorants and characterizing their molecular receptive range. It was hypothesized that once de-orphaning was accomplished for all olfactory receptor subtypes, we could unravel the combinatorial code of olfaction and solve the mystery of smell.