Adaptive evolution of scn4aa in Takifugu and Tetraodon  

作　　者：Hexing Wu Yonglai Hu Jing Wang Xiaoling Gong Baolong Bao 

机构地区：[1]Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources(Shanghai Ocean University),Ministry of Education,International Research Center for Marine Biosciences at Shanghai Ocean University,Ministry of Science and Technology,National Demonstration Center for Experimental Fisheries Science Education,Shanghai Ocean University,Shanghai,201306,China

出　　处：《Aquaculture and Fisheries》2024年第5期745-752,共8页渔业学报（英文）

基　　金：supported by National Natural Science Foundation of China (41176108);Key Innovation Project of Shanghai Education Commission (14zz145).

摘　　要：Tetrodotoxin(TTX)is a potent neurotoxin firstly discovered in the ovary of pufferfish.The genetic basis of voltage-gated sodium channel resistance to TTX has been widely studied,but it remains unclear in the evolution history of voltage-gated sodium channel resistance to TTX in pufferfish with different TTX concentrations.In this study,six scn4aa coding sequences of pufferfish were firstly cloned and sequenced,then used to investigate the adaptive evolution of scn4aa associated with TTX concentration and reconstruct ancestral sequences with seven scn4aa of other fishes.The result of CODEML(codon substitution model)program from the PAML(phylogenetic analysis by maximum likelihood)package shows only in the genus of Takifugu,which contains TTX highly in the liver,under positive selection.The result also indicates that three of four positively selected sites are located in the intracellular regions,which may compensate for normal function.The ancestral sequence reconstruction may suggest that the replacements providing weak toxin resistance might have appeared first in scn4aa,then the genus Takifugu evolved stronger resistance to TTX later.These results contribute to the explanation of the evolutional history of voltage-gated sodium channel resistance to TTX in pufferfish.

关 键 词：TETRODOTOXIN Voltage-gated sodium channel scn4aa Adaptive evolution PUFFERFISH 

分 类 号：S917[农业科学—水产科学]