红头美洲鹫和白头海雕的比较基因组学分析

Analysis of Comparative Genomics between Turkey Vulture and Bald Eagle

红头美洲鹫(Cathartes aura)是美洲鹫科的一种食腐鸟类,已知腐肉中有许多致病细菌可致肉食动物或者杂食动物中毒甚至死亡,然而红头美洲鹫并不受此影响。为探究红头美洲鹫可能发生了哪些与食腐特性相关的适应性改变,我们结合红头美洲鹫和白头海雕(Haliaeetus leucocephalus)的基因组数据进行比较研究,对筛选的快速进化基因分别进行注释和富集分析。结果显示,多数快速进化基因被富集到与免疫、能量代谢和消化相关的通路上;此外,有5个基因被富集到与嗅觉相关的"嗅觉转导"通路上。本研究表明,红头美洲鹫体内与免疫、能量代谢和消化相关的基因可能发生了与食腐特性相适应的快速进化,说明其可能从多个层面已形成一套很强的防御系统以抵御病菌的危害;与嗅觉相关的5个基因的快速进化可能与其在觅食过程中快速探测到腐肉气味密切相关。

The turkey vulture （Cathartes aura） is a scavenger belonging to Cathartidae family, which is not affected by the pathogenic bacteria which exsists in carrion and can cause carnivores and omnivores poisoning or even death. To investigate the possible adaptive changes that are associated with saprophagous characteristics on turkey vulture, we compared and analyzed the genomes of the turkey vulture and the bald eagle （Haliaeetus leucocephcdus） to identify the rapidly evolved genes which were studied by functional annotation and enrichment analyses. Our results showed that most rapidly evolved genes were enriched to the pathways associated with immunity, energy metabolism, and digestion. In addition, five genes were enriched to the ＂olfactory transduction＂ pathway related to olfaction. Our analysis suggested that genes related to immunity, energy metabolism and digestion in the turkey vulture might have evolved rapidly to adapt to the saprophagous characteristics, which indicated that the turkey vulture might have developed a strong defense system from multiple levels to protect against bacteria. The tachytelic evolution of five genes associated with olfaction might be closely related to the extraordinarily keen perception of carrion odors of the turkey vulture in the foraging process.