Zhao Simin, Huang Lan, Hu Yizhou, Bai Hao, Chang Guobin, Guo Qixin
Key Laboratory of Animal Genetics and Breeding and Molecular Design of Jiangsu Province, Yangzhou University, Yangzhou 225009, China.
Key Laboratory of Animal Genetics and Breeding and Molecular Design of Jiangsu Province, Yangzhou University, Yangzhou 225009, China; Joint International Research Laboratory of Agriculture and Agri-Product Safety, The Ministry of Education of China, Yangzhou University, Yangzhou 225009, China.
Poult Sci. 2025 Jun 28;104(9):105503. doi: 10.1016/j.psj.2025.105503.
Loss of flight in birds is an adaptive feature of evolutionary processes. Morphological and physiological differences are known among flightless bird species; however, the genetic mechanisms behind them are largely unexplored. Notably, wild birds and poultry that have lost flight owing to evolution and domestication, respectively, show phenotypic convergence, suggesting that different selective pressures through the same genetic pathways may cause loss of flight in birds; however, little is known about the genetic basis of this potential commonality. In this study, we obtained genomes of 28 wild bird and 15 duck species, and conducted comparative genomics and whole-genome resequencing analyses, respectively, to investigate the genetic basis underlying loss of flight in birds. The results of positive selection analysis using the genomic data of wild birds showed that 70 genes enriched in the cytoskeleton in muscle cells signaling pathway experienced strong positive selection, suggesting that this may be a key pathway leading to the loss of flight. Using the genomic data of domestic ducks for selective sweep analysis, we identified 139 candidate genes, among which FN1 and ANKRD1 were involved in the cytoskeleton in muscle cells signaling pathway; moreover, we detected strong positive selection signals in wild birds, suggesting that both wild birds and poultry may mediate flight loss through this pathway. Overall, this study deepens the understanding the evolution of flight in birds and provides novel insights and basis for future studies on flight in birds.
鸟类飞行能力的丧失是进化过程中的一种适应性特征。已知不会飞的鸟类物种之间存在形态和生理差异；然而，其背后的遗传机制在很大程度上尚未得到探索。值得注意的是，分别因进化和驯化而失去飞行能力的野生鸟类和家禽表现出表型趋同，这表明通过相同遗传途径的不同选择压力可能导致鸟类飞行能力的丧失；然而，对于这种潜在共性的遗传基础知之甚少。在本研究中，我们获得了28种野生鸟类和15种鸭类的基因组，并分别进行了比较基因组学和全基因组重测序分析，以研究鸟类飞行能力丧失的遗传基础。利用野生鸟类的基因组数据进行正选择分析的结果表明，70个富集于肌肉细胞信号通路中细胞骨架的基因经历了强烈的正选择，这表明这可能是导致飞行能力丧失的关键途径。利用家鸭的基因组数据进行选择性清除分析，我们鉴定出139个候选基因，其中FN1和ANKRD1参与肌肉细胞信号通路中的细胞骨架；此外，我们在野生鸟类中检测到强烈的正选择信号，这表明野生鸟类和家禽可能都通过这条途径介导飞行能力的丧失。总体而言，本研究加深了对鸟类飞行进化的理解，并为未来鸟类飞行研究提供了新的见解和依据。
