The new chimeric chiron genes evolved essential roles in zebrafish embryonic development by regulating NAD+ levels

作     者：Chengchi Fang Xiaoni Gan Chengjun Zhang Shunping He Chengchi Fang;Xiaoni Gan;Chengjun Zhang;Shunping He

作者机构：The Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of SciencesInstitute of HydrobiologyChinese Academy of SciencesWuhan 430072China Kunming Institute of BotanyChinese Academy of ScienceKunming 650201China University of Chinese Academy of SciencesBeijing 100039China Center for Excellence in Animal Evolution and GeneticsChinese Academy of SciencesKunming 650223China Huazhong Agricultural UniversityWuhan 430070China 

出 版 物：《Science China(Life Sciences)》 (中国科学（生命科学英文版）)

年 卷 期：2021年第64卷第11期

页      面：1929-1948页

核心收录：

学科分类：0710[理学-生物学] 0830[工学-环境科学与工程（可授工学、理学、农学学位）] 07[理学] 071008[理学-发育生物学] 

基　　金：This project is supported by the Pilot projects(XDB13020100) the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB31000000) the National Natural Science Foundation of China(NSFC,31601859). 

主　　题：new chimeric genes essential function NAD^(+)rate-limiting enzyme coevolution 

摘      要：The origination of new genes is important for generating genetic novelties for adaptive evolution and biological diversity.However, their potential roles in embryonic development, evolutionary processes into ancient networks, and contributions to adaptive evolution remain poorly investigated. Here, we identified a novel chimeric gene family, the chiron family, and explored its genetic basis and functional evolution underlying the adaptive evolution of Danioninae fishes. The ancestral chiron gene originated through retroposition of nampt in Danioninae 48–54 million years ago(Mya) and expanded into five duplicates(chiron1–5) in zebrafish 1–4 Mya. The chiron genes(chirons) likely originated in embryonic development and gradually extended their expression in the testis. Functional experiments showed that chirons were essential for zebrafish embryo development. By integrating into the NAD^(+) synthesis pathway, chirons could directly catalyze the NAD^(+) rate-limiting reaction and probably impact two energy metabolism genes(nmnat 1 and naprt) to be under positive selection in Danioninae fishes. Together,these results mainly demonstrated that the origin of new chimeric chiron genes may be involved in adaptive evolution by integrating and impacting the NAD^(+) biosynthetic pathway. This coevolution may contribute to the physiological adaptation of Danioninae fishes to widespread and varied biomes in Southeast Asian.