Relaxed selective pressure on an essential component of pheromone transduction in primate evolution.
The vomeronasal organ (VNO) detects pheromones in many vertebrate species but is likely to be vestigial in humans. TRPC2(TRP2), a gene that is essential for VNO function in the mouse, is a pseudogene in humans. Because TRPC2 is expressed only in the VNO, the loss of selective pressure on this gene can serve as a molecular marker for the time at which the VNO became vestigial. By analyzing sequence data from the TRPC2 gene of 15 extant primate species, we provide evidence that the VNO was most likely functional in the common ancestor of New World monkeys and Old World monkeys and apes, but then became vestigial in the common ancestor of Old World monkeys and apes. We propose that, at this point in evolution, other modalities, notably the development of color vision, may have largely replaced signaling by pheromones.
Liman
Emily R
ER
Department of Biological Sciences and Program in Neurosciences, University of Southern California, Los Angeles, CA 90089, USA. Liman@USC.edu
Innan
Hideki
H
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015220:Calcium Channels / Q000235:genetics*; D002427:Cebidae / Q000235:genetics; D002520:Cercopithecidae / Q000235:genetics; D004247:DNA / Q000235:genetics; D019143:Evolution, Molecular; D015186:Hominidae / Q000235:genetics; D006801:Humans; D007473:Ion Channels; D008565:Membrane Proteins; D051379:Mice; D008969:Molecular Sequence Data; D009154:Mutation; D010675:Pheromones / Q000502:physiology*; D010802:Phylogeny; D011323:Primates / Q000235:genetics* / Q000502:physiology*; D012641:Selection, Genetic; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity; D050052:TRPC Cation Channels; D050053:TRPM Cation Channels; D019147:Vomeronasal Organ / Q000502:physiology
D015220:Calcium Channels; D007473:Ion Channels; D008565:Membrane Proteins; D010675:Pheromones; D050052:TRPC Cation Channels; C491859:TRPC2 protein, human; D050053:TRPM Cation Channels; C121934:TRPM2 protein, human; D004247:DNA