check relationship to olfactory system. Evolution: The morphological components of the VNS are found only in tetrapods, but the genetic components of the system have been found in teleost fish, in addition to tetrapods. In tetrapods, the VNS was thought to be the olfactory system for detecting pheromones, while the main olfactory system detected general odorants (Scalia and Winans 1975). However, experimental evidence suggests that there is not such a clear functional distinction (Restrepo et al. 2004; Baxi, Dorries, and Eisthen 2006; Spehr et al. 2006; Kelliher 2007). Sea lampreys produce unique bile acids which act as pheromones both in migration and mate finding (Li, Sorensen, and Gallaher 1995; Li et al. 2002; Siefkes and Li 2004). However, bile acids in teleost fish are known to require components of the main olfactory signal transduction pathway (Hansen et al. 2003), and interruption of the VNS signal transduction pathway had no effect on bile acid olfactory response (Hansen et al. 2003)[Grus - EVOLUTION OF THE VOMERONASAL SYSTEM VIEWED THROUGH SYSTEM-SPECIFIC GENES]

uberon

UBERON:0009954

• vomeronasal organ