title: Trpc2 pseudogenization dynamics in bats reveal ancestral vomeronasal signaling, then pervasive loss.
abstract: Comparative methods are often used to infer loss or gain of complex phenotypes, but few studies take advantage of genes tightly linked with complex traits to test for shifts in the strength of selection. In mammals, vomerolfaction detects chemical cues mediating many social and reproductive behaviors and is highly conserved, but all bats exhibit degraded vomeronasal structures with the exception of two families (Phyllostomidae and Miniopteridae). These families either regained vomerolfaction after ancestral loss, or there were many independent losses after diversification from an ancestor with functional vomerolfaction. In this study, we use the Transient receptor potential cation channel 2 (Trpc2) as a molecular marker for testing the evolutionary mechanisms of loss and gain of the mammalian vomeronasal system. We sequenced Trpc2 exon 2 in over 100 bat species across 17 of 20 chiropteran families. Most families showed independent pseudogenizing mutations in Trpc2, but the reading frame was highly conserved in phyllostomids and miniopterids. Phylogeny-based simulations suggest loss of function occurred after bat families diverged, and purifying selection in two families has persisted since bats shared a common ancestor. As most bats still display pheromone-mediated behavior, they might detect pheromones through the main olfactory system without using the Trpc2 signaling mechanism.
authors.affiliation: Department of Ecology and Evolution, Stony Brook University, Stony Brook, New York, 11794.
authors.forename: Laurel R
authors.initials: LR
authors.lastname: Yohe
authors.affiliation: Department of Ecology and Evolution, Stony Brook University, Stony Brook, New York, 11794.
authors.forename: Ramatu
authors.initials: R
authors.lastname: Abubakar
authors.affiliation: Department of Ecology and Evolution, Stony Brook University, Stony Brook, New York, 11794.
authors.forename: Christina
authors.initials: C
authors.lastname: Giordano
authors.affiliation: Department of Biology, University of Massachusetts, Amherst, Massachusetts, 01003.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Dumont
authors.affiliation: Carl R. Woese Institute for Genomic Biology, University of Illinois, Urbana, Illinois, 61801.|School of Integrative Biology, Institute for Genome Biology, University of Illinois, Urbana, Illinois, 61801.
authors.forename: Karen E
authors.initials: KE
authors.lastname: Sears
authors.affiliation: School of Biological and Chemical Sciences, Queen Mary University of London, London, E1 4NS, United Kingdom.
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Rossiter
authors.affiliation: Department of Ecology and Evolution, Stony Brook University, Stony Brook, New York, 11794.|Consortium for Inter-Disciplinary Environmental Research, Stony Brook University, Stony Brook, New York, 11794.
authors.forename: Liliana M
authors.initials: LM
authors.lastname: Dávalos
mesh_terms: D000818:Animals; D005075:Biological Evolution; D002685:Chiroptera / Q000235:genetics / Q000502:physiology*; D019143:Evolution, Molecular; D010802:Phylogeny; D011544:Pseudogenes; D017422:Sequence Analysis, DNA; D015398:Signal Transduction; D050051:Transient Receptor Potential Channels / Q000235:genetics* / Q000378:metabolism; D019147:Vomeronasal Organ / Q000502:physiology*
chemical_list: D050051:Transient Receptor Potential Channels
keywords: Pheromone; purifying selection; relaxed selection, Trpc2; vomeronasal system