Luo Chaoyang, Xu Xionghui, Zhao Chengfa, Wang Qiuping, Wang Rongxing, Lang Datian, Zhang Juan, Hu Wenxian, Mu Yuan
Institute of Eastern-Himalaya Biodiversity Research, Dali University, Dali, Yunnan, China.
Department of Agronomy and Life Science, Zhaotong University, Zhaotong, Yunnan, China.
Integr Zool. 2024 Dec 11. doi: 10.1111/1749-4877.12927.
Birds exhibit remarkable variations in body size, making them an ideal group for the study of adaptive evolution. However, the genetic mechanisms underlying body size evolution in avian species remain inadequately understood. This study investigates the evolutionary patterns of avian body size by analyzing 15 body-size-related genes, including GHSR, IGF2BP1, and IGFBP7 from the growth hormone/insulin-like growth factor axis, EIF2AK3, GALNS, NCAPG, PLOD1, and PLAG1 associated with tall stature, and ACAN, OBSL1, and GRB10 associated with short stature, four genes previously reported in avian species: ATP11A, PLXDC2, TNS3, and TUBGCP3. The results indicate significant adaptive evolution of body size-related genes across different avian lineages. Notably, in the IGF2BP1 gene, a significant positive correlation was observed between the evolutionary rate and body size, suggesting that larger bird species exhibit higher evolutionary rates of the IGF2BP1 gene. Furthermore, the IGFBP7 and PLXDC2 genes demonstrated accelerated evolution in large- and medium-sized birds, respectively, indicating distinct evolutionary patterns for these genes among birds of different sizes. The branch-site model analysis identified numerous positively selected sites, primarily concentrated near functional domains, thereby reinforcing the critical role of these genes in body size evolution. Interestingly, extensive convergent evolution was detected in lineages with larger body sizes. This study elucidates the genetic basis of avian body size evolution for the first time, identifying adaptive evolutionary patterns of body size-related genes across birds of varying sizes and documenting patterns of convergent evolution. These findings provide essential genetic data and novel insights into the adaptive evolution of body size in birds.
鸟类在体型上表现出显著差异，使其成为研究适应性进化的理想群体。然而，鸟类体型进化背后的遗传机制仍未得到充分理解。本研究通过分析15个与体型相关的基因来探究鸟类体型的进化模式，这些基因包括生长激素/胰岛素样生长因子轴中的GHSR、IGF2BP1和IGFBP7，与高身材相关的EIF2AK3、GALNS、NCAPG、PLOD1和PLAG1，与矮身材相关的ACAN、OBSL1和GRB10，以及先前在鸟类中报道的四个基因：ATP11A、PLXDC2、TNS3和TUBGCP3。结果表明，不同鸟类谱系中与体型相关的基因存在显著的适应性进化。值得注意的是，在IGF2BP1基因中，进化速率与体型之间存在显著的正相关，这表明体型较大的鸟类物种表现出更高的IGF2BP1基因进化速率。此外，IGFBP7和PLXDC2基因分别在大中型鸟类中表现出加速进化，表明这些基因在不同体型鸟类中的进化模式不同。分支位点模型分析确定了许多正选择位点，主要集中在功能域附近，从而加强了这些基因在体型进化中的关键作用。有趣的是，在体型较大的谱系中检测到广泛的趋同进化。本研究首次阐明了鸟类体型进化的遗传基础，确定了不同体型鸟类中与体型相关基因的适应性进化模式，并记录了趋同进化模式。这些发现为鸟类体型的适应性进化提供了重要的遗传数据和新见解。
