An odorant receptor for a key odor constituent of ambergris

Ambergris, a substance derived from the digestive system of sperm whales, has been valued for centuries for its unique aromatic properties. However, historical accounts indicate that certain human populations, particularly in East Asia, utilized ambergris without regard for its odor quality. These observations suggest that ambergris offers a model for studying how pleasant olfactory perception and its regional variations are constructed. Despite its historical and cultural significance, the molecular basis of ambergris perception has remained unclear. Here, we identified OR7A17 as an odorant receptor tuned to (-)-Ambroxide, a key odorant in ambergris. Analysis of genetic and functional variations in OR7A17 revealed that non-functional alleles of this receptor are prevalent in human populations, especially in East Asia. Individuals lacking functional OR7A17 alleles could still detect (-)-Ambroxide but found its scent less pleasant compared to those with functional alleles. These findings elucidate a molecular mechanism that influences the perceived pleasantness of ambergris and shed light on its enduring legacy in perfumery.