AUTHOR=Wang Qiu-Ping , Luo Chao-Yang , Xu Xiong-Hui , Hu Wen-Xian , Gai Yu-Lin , Gong You-Jing , Mu Yuan 

TITLE=Adaptive evolution of antioxidase-related genes in hypoxia-tolerant mammals

JOURNAL=Frontiers in Genetics

VOLUME=15

YEAR=2024

URL=https://www.frontiersin.org/journals/genetics/articles/10.3389/fgene.2024.1315677

DOI=10.3389/fgene.2024.1315677

ISSN=1664-8021

ABSTRACT=<p>To cope with the damage from oxidative stress caused by hypoxia, mammals have evolved a series of physiological and biochemical traits, including antioxidant ability. Although numerous research studies about the mechanisms of hypoxia evolution have been reported, the molecular mechanisms of antioxidase-related genes in mammals living in different environments are yet to be completely understood. In this study, we constructed a dataset comprising 7 antioxidase-related genes (<italic>CAT</italic>, <italic>SOD1</italic>, <italic>SOD2</italic>, <italic>SOD3</italic>, <italic>GPX1</italic>, <italic>GPX2</italic>, and <italic>GPX3</italic>) from 43 mammalian species to implement evolutionary analysis. The results showed that six genes (<italic>CAT</italic>, <italic>SOD1</italic>, <italic>SOD2</italic>, <italic>SOD3</italic>, <italic>GPX1</italic>, and <italic>GPX3</italic>) have undergone divergent evolution based on the free-ratio (M1) model. Furthermore, multi-ratio model analyses uncovered the divergent evolution between hypoxic and non-hypoxic lineages, as well as various hypoxic lineages. In addition, the branch-site model identified 9 positively selected branches in 6 genes (<italic>CAT</italic>, <italic>SOD1</italic>, <italic>SOD2</italic>, <italic>SOD3</italic>, <italic>GPX2</italic>, and <italic>GPX3</italic>) that contained 35 positively selected sites, among which 31 positively selected sites were identified in hypoxia-tolerant branches, accounting for 89% of the total number of positively selected sites. Interestingly, 65 parallel/convergent sites were identified in the 7 genes. In summary, antioxidase-related genes are subjected to different selective pressures among hypoxia-tolerant species living in different habitats. This study provides a valuable insight into the molecular evolution of antioxidase-related genes in hypoxia evolution in mammals.</p>