Adaptive Divergence and Functional Convergence: The Evolution of Pulmonary Gene Expression in Amphibians of the Qingzang Plateau

Background The Qingzang Plateau, with its harsh environmental conditions—low oxygen, high ultraviolet radiation, and significant temperature fluctuations—demands specialized adaptations for survival. While extensive research has focused on genetic adaptations to these extreme conditions, the role of gene expression in amphibian adaptation remains relatively unexplored. This study aims to investigate pulmonary gene expression variation across multiple amphibian species on the plateau, seeking to understand how genetic and environmental factors contribute to gene expression evolution in these challenging environments. Results Our analysis reveals significant variation in pulmonary gene expression among amphibian species, driven by both genetic diversity and environmental pressures. Contrary to the predictions of the unbounded neutral evolution model, we found no significant correlation between gene expression divergence and genetic distance. Instead, species-specific characteristics and environmental factors, such as UVB radiation, oxygen availability, and temperature, significantly influence gene expression patterns. For example, B. gargarizans exhibited high gene expression responsiveness to multiple environmental factors, while S. boulengeri showed limited responsiveness, suggesting different adaptive strategies among species. Despite divergence in specific gene expression profiles, functional enrichment analysis highlighted a convergence in critical biological processes like angiogenesis, ATP binding, and cellular responses to environmental stressors, which are vital for high-altitude survival. Conclusion This study demonstrates that the evolution of gene expression in high-altitude amphibians is complex, with both genetic and environmental factors playing significant roles. The convergence in essential biological functions, despite divergence in specific gene expression profiles, underscores the shared adaptive requirements of high-altitude environments. These findings provide valuable insights into the mechanisms of gene expression evolution and highlight the importance of considering both genetic and environmental components when studying adaptation in extreme habitats.