Abstract: The lesser short-nosed fruit bat (Cynopterus brachyotis) is a bat species commonly found in urban areas. A published study showed that rapid urbanization has led to a significant decrease in genetic diversity in this fruit bat. However, the genetic mechanisms underlying this species’ adaptations to urban environments have not been investigated. Based on the published population genome resequencing data from historical samples collected in 1931 and contemporary samples from 2011 - 2012, this study investigated the effects of rapid urbanization on the lesser shortnosed fruit bat and the genetic basis of adaptations to urbanization, using four methods (allele frequency analysis, selection signal detection based on population genetic differentiation, selection signal detection based on haplotypes, and detection of selected loci). Our results show that 669 selected genes were identified in the historical population and these genes were functionally enriched in visual and olfactory pathways. In contrast, 2 013 selected genes were identified in the contemporary population and these genes were enriched in immune, gustatory, and auditory pathways in addition to visual and olfactory-related pathways. These results suggest that rapid urbanization may have affected multiple sensory systems and immune systems in this species. Therefore, adaptive molecular evolution of immune, gustatory, and auditory genes may have occurred in C. brachyotis in response to rapid urbanization.

Key words: Cynopterus brachyotis, Urbanization, Population genomics, Selection signals

摘要： 短耳犬蝠(Cynopterus brachyotis)是栖息在城市的典型蝙蝠物种。已发表的研究表明，短耳犬蝠的遗传多样性显著降低与快速城市化紧密相关，但该物种适应城市环境的遗传学基础仍缺乏研究。本研究基于已发表的短耳犬蝠历史样本(1931年)和当代样本(2011—2012年)的群体基因组重测序数据，通过位点突变频率、基于群体遗传分化的选择信号检测方法、基于单倍型的选择信号检测方法和受选择基因座检测方法，探究了快速城市化对短耳犬蝠的影响及其适应城市化的遗传学基础。研究结果表明：短耳犬蝠历史群体中鉴定到669个受选择基因，基因功能富集主要集中在视觉和嗅觉等通路；在当代群体中鉴定到2 013个受选择基因，这些基因除了参与视觉和嗅觉相关通路外，还在免疫、味觉和听觉等通路中发挥作用。该结果提示，快速城市化可能影响短耳犬蝠的感官系统和免疫系统；为了适应快速城市化，短耳犬蝠可能在免疫、味觉和听觉等功能方面发生了适应性演化。

关键词: 短耳犬蝠, 城市化, 群体基因组, 选择信号