@article{386faae70735464cbb2b790e2832bb1e,
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.",
keywords = "Pheromone, purifying selection, relaxed selection, Trpc2, vomeronasal system",
author = "Yohe, {Laurel R.} and Ramatu Abubakar and Christina Giordano and Elizabeth Dumont and Sears, {Karen E.} and Rossiter, {Stephen J.} and D{\'a}valos, {Liliana M.}",
note = "Funding Information: This work was supported by the National Science Foundation Graduate Research Fellowship and NSF-DEB 1442142. The Indiana University Mason server funded through NSF-DBI 1458641 provided computing resources for the simulations in this study. For tissue samples, we thank the following individuals and collections: N. B. Simmons and staff of the Ambrose Monell Cryo-Collection at the American Museum of Natural History; B. Patterson and J. D. Phelps at the Field Museum; J. Cook, J. Dunnum, and M. Campbell at the Museum of Southwestern Biology; V. Pacheco at the Museo de Historia Natural at the Universidad Nacional Mayor de San Marcos; C. Conroy at the Museum of Vertebrate Zoology of the University of California, Berkeley; K. Helgen at the Smithsonian Institution; B. Lim and J. Enger at the Royal Ontario Museum; and R. J. Baker and the Mammalogy staff at the Museum of Texas Tech University. We thank E. Leung for assistance with laboratory work. We thank the University of Arizona Genetics Core Facility for Sanger sequencing. For helpful comments and suggestions on the manuscript, we thank N. Holowka, two anonymous reviewers, and B. Igi{\'c} for suggestions and stimulating discussion. We thank N. Holowka, B. Sumner, and A. Tejedor for contributing illustrations. The authors contributed as follows. LRY conceived the ideas, designed and executed the study, collected and analyzed the data, and wrote the manuscript. RA and CMG assisted in data cxollection and edited the manuscript. LMD helped design the study, collected samples, and wrote the manuscript. SJR assisted in sample collection. SJR, KES, and ERD were involved in funding acquisition and provided feedback. Models, code, and input for analyses are deposited on Dryad (DOI: https://doi.org/10.5061/dryad.gr1pk); new sequence data are deposited to Genbank (KX537508-KX537612). Publisher Copyright: {\textcopyright} 2017 The Author(s). Evolution {\textcopyright} 2017 The Society for the Study of Evolution.",
year = "2017",
month = apr,
day = "1",
doi = "10.1111/evo.13187",
language = "English (US)",
volume = "71",
pages = "923--935",
journal = "Evolution",
issn = "0014-3820",
publisher = "Society for the Study of Evolution",
number = "4",
}