Plateau Grass and Greenhouse Flower? Distinct Genetic Basis of Closely Related Toad Tadpoles Respectively Adapted to High Altitude and Karst Caves

Genes

Meihua Zhang¹  Bin Wang¹  Wei Zhu¹  Cheng Li¹  Feng Xie²  Liming Chang²  Shengchao Shi²  Jianping Jiang² 

[1] Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China;;CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization &

关键词: genetic adaptation;    positively selected gene;    fast evolving gene;    high elevation;    karst cave;    environmental gradient;   

DOI  :  10.3390/genes11020123

来源: DOAJ

【 摘 要 】

Genetic adaptation to extremes is a fascinating topic. Nevertheless, few studies have explored the genetic adaptation of closely related species respectively inhabiting distinct extremes. With deep transcriptome sequencing, we attempt to detect the genetic architectures of tadpoles of five closely related toad species adapted to the Tibetan Plateau, middle-altitude mountains and karst caves. Molecular evolution analyses indicated that not only the number of fast evolving genes (FEGs), but also the functioning coverage of FEGs, increased with elevation. Enrichment analyses correspondingly revealed that the highland species had most of the FEGs involved in high-elevation adaptation, for example, amino acid substitutions of XRCC6 in its binding domains might improve the capacity of DNA repair of the toad. Yet, few FEGs and positively selected genes (PSGs) involved in high-elevation adaptation were identified in the cave species, and none of which potentially contributed to cave adaptation. Accordingly, it is speculated that in the closely related toad tadpoles, genetic selection pressures increased with elevation, and cave adaptation was most likely derived from other factors (e.g., gene loss, pseudogenization or deletion), which could not be detected by our analyses. The findings supply a foundation for understanding the genetic adaptations of amphibians inhabiting extremes.

【 授权许可】

Unknown