title: Positive selection during the diversification of class I vomeronasal receptor-like (V1RL) genes, putative pheromone receptor genes, in human and primate evolution.
abstract: Vomeronasal receptors are the major receptors for pheromones in vertebrates, and five putative type 1 vomeronasal receptors (V1RL) have been identified in humans. The evolution of the V1RL1 gene in non-human primates, and patterns of selection on V1RL genes, were investigated. The presumed ortholog of V1RL1 was sequenced from 13 species of nonhuman primate, and in eight of these species V1RL1 was a pseudogene. Phylogenetic reconstructions reveal that V1RL1 pseudogene formation occurred independently in multiple primate lineages. Using maximum likelihood estimates of dN/dS ratios in PAML, we show that V1RL genes have evolved under neutral evolution in lineages in which they became a pseudogene. In contrast, among lineages in which V1RL genes contain an open reading frame, the majority of sites are under purifying selection and a minority are under significant positive selection. These results provide an interesting case where all three categories of selection can be teased apart in the same data set using maximum likelihood methods. The finding of positive selection on V1RL genes during primate evolution provides indirect support for the hypothesis that V1RL genes have a function in species-specific pheromone detection in primates.
authors.affiliation: Institute of Biological Anthropology, University of Oxford, Oxford, England. nim21@cam.ac.uk
authors.forename: Nicholas I
authors.initials: NI
authors.lastname: Mundy
authors.forename: Shelley
authors.initials: S
authors.lastname: Cook
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D005075:Biological Evolution; D002630:Chemotactic Factors / Q000096:biosynthesis* / Q000235:genetics*; D019143:Evolution, Molecular; D005091:Exons; D015186:Hominidae; D006801:Humans; D016013:Likelihood Functions; D008957:Models, Genetic; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D011323:Primates; D043563:Receptors, Pheromone / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D012984:Software
chemical_list: D002630:Chemotactic Factors; D043563:Receptors, Pheromone; C414724:VN1R1 protein, human