基因组水平蝙蝠嗅觉受体基因的分子进化

Molecular evolution of olfactory receptor genes in bats revealed by a genome-wide analysis

翼手目动物(俗称蝙蝠)的食性分化显著,不同食性的蝙蝠具有显著不同的嗅球大小。为了研究嗅觉是否影响了蝙蝠食性的进化,我们利用网上已公布的10种蝙蝠基因组的数据,通过同源比对的方法鉴定出所有的嗅觉受体基因,并进行嗅觉受体基因亚家族的分类,进而比较嗅觉受体基因亚家族的数目差异。结果显示,蝙蝠的嗅觉受体基因与其它哺乳动物一样,都可以分为13个单系起源的亚家族;在Yinpterochiroptera亚目中,OR1/3/7、OR2/13、OR5/8/9等3个嗅觉受体亚家族在食果蝙蝠中均发生了不同程度的扩张,基因数目显著地多于食虫蝙蝠,提示嗅觉在食果蝙蝠取食过程中具有重要的作用。因此,本研究在基因组水平上重现了蝙蝠嗅觉受体基因的进化历史,揭示了3个嗅觉受体基因亚家族的功能可能与食果蝙蝠的食性相关,突出了嗅觉对动物食性的重要作用。

Chiroptera, commonly known as bats, show a huge diversity in diets, which may have shaped the sizes of olfac- tory bulbs in bats with distinct diets. To study whether olfaction impacts the dietary diversification in bats, we identified all olfactory receptor （i. e. OR） genes with a homology-based approach from the published genome data of ten species of bats, and assigned each gene into an OR gene subfamily. Our results showed that bats also possess 13 monophyletie subfamilies of OR genes, as reported in other mammals. Furthermore, within the suborder Yinpteroehiroptera, we identified three subfami- lies （OR1/3/7, OR2/13, OR5/8/9 ） with significant expansions in fruit-eating bats compared to insect-eating species, which suggested that the three gene subfamilies are associated with the recognition of ripe fruit smell. Together, this work recovered the evolutionary history of OR genes in bats using a genome-wide analysis, and identified some OR genes that may be specialized for the recognition of ripe fruit smell in fruit-eating bats. These results highlight the importance of olfaction in dietary selection for animals.