Abstract: The vomeronasal olfactory system (VNS) in mammals mainly detects pheromones, which play a crucial role in mammalian reproduction and social behavior. To investigate the molecular evolution of vomeronasal receptors, a comparative genomics approach was employed to analyze the vomeronasal receptor V1R genes from the published genomes of ten species of bats. Results showed that V1R genes are present in all ten species. However, V1R genes in most species are pseudogenes, although intact V1R genes were identified in Megaderma lyra and Pteronotus parnellii. Further analysis showed that the intact V1R gene in M. lyra is under neutral selection, indicative of vomeronasal insensitivity in this species. We observed significant purifying selection acting on three intact V1R genes in P. parnelli, suggesting that the function of vomeronasal organ in P. parnelli is retained. These results are consistent with morphological data from the bat VNS  and TRPC2 analysis of bat . Together, our study suggests widespread losses of vomeronasal olfactory function in bats, and the reasons underlying the vomeronasal insensitivity are complicated. We call for an in-depth investigation in the future.

Key words: Bat, Vomeronasal system, V1R gene, Pseudogenization

摘要： 哺乳动物的犁鼻嗅觉系统 (VNS)主要感知信息素，而信息素在动物的生殖和社会行为中起着重要的调控作用。为了研究蝙蝠犁鼻器受体的分子进化，我们以已发表基因组的10种蝙蝠为研究对象，采用比较基因组学方法，对蝙蝠犁鼻器受体V1R基因进行分析。研究结果显示：10种蝙蝠中都存在V1R基因。尽管在印度假吸血蝠和帕氏髯蝠中存在完整的V1R基因,但大部分蝙蝠中的V1R基因却都是假基因。进一步的分析表明，假吸血蝠中仅有的1个全长的V1R基因处于中性进化状态，揭示其犁鼻器很可能已经丧失功能；而帕氏髯蝠中3个全长的V1R基因都受到了强烈的净化选择，提示其犁鼻嗅觉功能仍然保留，这些结果和蝙蝠犁鼻器形态学研究和蝙蝠TRPC2基因的研究结果相一致。我们的研究表明大部分蝙蝠丧失了犁鼻嗅觉功能，而犁鼻器功能丧失的原因比较复杂，有待进一步研究。

关键词: 蝙蝠, 犁鼻器, V1R基因, 假基因化