Adaptive evolution of antioxidase-related genes in hypoxia-tolerant mammals.

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 (CAT, SOD1, SOD2, SOD3, GPX1, GPX2, and GPX3) from 43 mammalian species to implement evolutionary analysis. The results showed that six genes (CAT, SOD1, SOD2, SOD3, GPX1, and GPX3) 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 (CAT, SOD1, SOD2, SOD3, GPX2, and GPX3) 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.

Taxonomy of the Panorpa guttata group (Mecoptera: Panorpidae), with descriptions of fourteen new species from China.

Panorpa Linnaeus, 1758 is the largest genus in the scorpionfly family Panorpidae. It is considered a paraphyletic taxon and needs further revisions. In this paper, we present a taxonomic study of the Panorpa guttata group, including 23 closely related species, with fourteen species new to science: Panorpa caoweii Wang, sp. n., Panorpa dali Wang, sp. n., Panorpa duanyu Wang Gong, sp. n., Panorpa hani Wang, sp. n., Panorpa hirundo Wang, sp. n., Panorpa huangguiqiangi Wang, sp. n., Panorpa jiangrixini Wang, sp. n., Panorpa jinfoshana Wang, sp. n., Panorpa latiloba Wang, sp. n., Panorpa nanzhao Wang, sp. n., Panorpa stella Wang, sp. n., Panorpa substricta Wang, sp. n., Panorpa xiaofeng Wang Gong, sp. n., and Panorpa xuzhu Wang Gong, sp. n. We also provide a distributional map, keys to species, and discussions regarding the taxonomic implications and biological information of the P. guttata group.