title: Evolutionary deterioration of the vomeronasal pheromone transduction pathway in catarrhine primates.
abstract: Pheromones are water-soluble chemicals released and sensed by individuals of the same species to elicit social and reproductive behaviors or physiological changes; they are perceived primarily by the vomeronasal organ (VNO) in terrestrial vertebrates. Humans and some related primates possess only vestigial VNOs and have no or significantly reduced ability to detect pheromones, a phenomenon not well understood at the molecular level. Here we show that genes encoding the TRP2 ion channel and V1R pheromone receptors, two components of the vomeronasal pheromone signal transduction pathway, have been impaired and removed from functional constraints since shortly before the separation of hominoids and Old World monkeys approximately 23 million years ago, and that the random inactivation of pheromone receptor genes is an ongoing process even in present-day humans. The phylogenetic distribution of vomeronasal pheromone insensitivity is concordant with those of conspicuous female sexual swelling and male trichromatic color vision, suggesting that a vision-based signaling-sensory mechanism may have in part replaced the VNO-mediated chemical-based system in the social/reproductive activities of hominoids and Old World monkeys (catarrhines).
authors.affiliation: Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109, USA. jianzhi@umich.edu
authors.forename: Jianzhi
authors.initials: J
authors.lastname: Zhang
authors.forename: David M
authors.initials: DM
authors.lastname: Webb
mesh_terms: D000818:Animals; D001483:Base Sequence; D005075:Biological Evolution; D002427:Cebidae / Q000235:genetics / Q000502:physiology; D002520:Cercopithecidae / Q000235:genetics / Q000502:physiology*; D002630:Chemotactic Factors / Q000235:genetics*; D018389:Codon, Nonsense; D019143:Evolution, Molecular; D005091:Exons / Q000235:genetics; D005260:Female; D005796:Genes; D015186:Hominidae / Q000235:genetics / Q000502:physiology; D006801:Humans; D008297:Male; D008565:Membrane Proteins / Q000235:genetics*; D051379:Mice; D008969:Molecular Sequence Data; D009475:Neurons, Afferent / Q000502:physiology; D010675:Pheromones / Q000502:physiology*; D010802:Phylogeny; D051381:Rats; D016415:Sequence Alignment; D012689:Sequence Homology, Nucleic Acid; D012726:Sexual Behavior, Animal; D015398:Signal Transduction; D013045:Species Specificity; D050052:TRPC Cation Channels; D019147:Vomeronasal Organ / Q000502:physiology*
chemical_list: D002630:Chemotactic Factors; D018389:Codon, Nonsense; D008565:Membrane Proteins; D010675:Pheromones; D050052:TRPC Cation Channels; C491859:TRPC2 protein, human; C113139:Trp2 protein, vertebrate; C491858:Trpc2 protein, mouse; C491857:Trpc2 protein, rat; C485895:V1ra1 protein, mouse; C414724:VN1R1 protein, human