HSP90 AA1 is part of the heat shock protein 90 gene family and has important functions against heat stress. We report a case of molecular level parallel evolution of the HSP90 AA1 gene in high elevation amphibians. HS...HSP90 AA1 is part of the heat shock protein 90 gene family and has important functions against heat stress. We report a case of molecular level parallel evolution of the HSP90 AA1 gene in high elevation amphibians. HSP90 AA1 gene sequences of four high-elevation anurans, Bufo gargarizans, Nanorana parkeri, Rana kukunoris, and Scutiger boulengeri, were compared along with five of their low-elevation relatives. A total of 16 amino-acid sites were identified as parallel evolution between N. parkeri and R. kukunoris. We generated both model based（Zhang and Kumar＇s test） and empirical data based（parallel/divergence plotting） null distributions for non-parallel evolution, and both methods clearly determined that the observed number of parallel substitutions were significantly more than the null expectation. Furthermore, on the HSP90 AA1 gene tree, N. parkeri and R. kukunoris formed a strongly supported clade that was away from their respective relatives. This study provides a clear case of molecular parallel evolution, which may have significant implications in understanding the genetic mechanisms of high-elevation adaptation.展开更多
Habitat shift is a key innovation that has contributed to the extreme diversification of insects. Most groups are well-adapted to more or less specific environments and shifts usually only happen between similar habit...Habitat shift is a key innovation that has contributed to the extreme diversification of insects. Most groups are well-adapted to more or less specific environments and shifts usually only happen between similar habitats. To colonize a pro- foundly different habitat type does not only present ecological opportunities but also great challenges. We used Hydrophiloidea （water scavenger beetles） as a system to study transitions between terrestrial and aquatic environments. We estimated the diversi- fication rate of different clades using phylogenetic trees based on a representative taxon sampling and six genes. We also investi- gated possible evolutionary changes in candidate genes following habitat shifts. Our results suggest that the diversification rate is relatively slow （0.039-0.050 sp/My） in the aquatic lineage, whereas it is distinctly increased in the secondarily terrestrial clade （0.055-0.075 sp/My）. Our results also show that aquatic species have a G （Glycine） or S （Serine） amino acid at a given site of COI, while terrestrial species share an A （Alanine） amino acid with terrestrial outgroups. This indicates that habitat factors may create selection pressure on the evolution of functional genes and cause homoplasy in molecular evolution [Current Zoology 60 （5）： 561-570, 2014 ]展开更多
基金supported by the National Nature Science Foundation of China (grant number 31328021 to Jinzhong FU)NSERC of Canada (a discovery grant to Jinzhong FU)
文摘HSP90 AA1 is part of the heat shock protein 90 gene family and has important functions against heat stress. We report a case of molecular level parallel evolution of the HSP90 AA1 gene in high elevation amphibians. HSP90 AA1 gene sequences of four high-elevation anurans, Bufo gargarizans, Nanorana parkeri, Rana kukunoris, and Scutiger boulengeri, were compared along with five of their low-elevation relatives. A total of 16 amino-acid sites were identified as parallel evolution between N. parkeri and R. kukunoris. We generated both model based（Zhang and Kumar＇s test） and empirical data based（parallel/divergence plotting） null distributions for non-parallel evolution, and both methods clearly determined that the observed number of parallel substitutions were significantly more than the null expectation. Furthermore, on the HSP90 AA1 gene tree, N. parkeri and R. kukunoris formed a strongly supported clade that was away from their respective relatives. This study provides a clear case of molecular parallel evolution, which may have significant implications in understanding the genetic mechanisms of high-elevation adaptation.
文摘Habitat shift is a key innovation that has contributed to the extreme diversification of insects. Most groups are well-adapted to more or less specific environments and shifts usually only happen between similar habitats. To colonize a pro- foundly different habitat type does not only present ecological opportunities but also great challenges. We used Hydrophiloidea （water scavenger beetles） as a system to study transitions between terrestrial and aquatic environments. We estimated the diversi- fication rate of different clades using phylogenetic trees based on a representative taxon sampling and six genes. We also investi- gated possible evolutionary changes in candidate genes following habitat shifts. Our results suggest that the diversification rate is relatively slow （0.039-0.050 sp/My） in the aquatic lineage, whereas it is distinctly increased in the secondarily terrestrial clade （0.055-0.075 sp/My）. Our results also show that aquatic species have a G （Glycine） or S （Serine） amino acid at a given site of COI, while terrestrial species share an A （Alanine） amino acid with terrestrial outgroups. This indicates that habitat factors may create selection pressure on the evolution of functional genes and cause homoplasy in molecular evolution [Current Zoology 60 （5）： 561-570, 2014 ]
