Ma Xiuhui, Dai Wei, Kang Jingliang, Yang Liandong, He Shunping
The Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei, 430072, China School of Life Science, Southwest University, Beibei, Chongqing, 400715, China.
The Key Laboratory of Aquatic Biodiversity and Conservation of Chinese Academy of Sciences, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei, 430072, China Institute of Hydrobiology, University of Chinese Academy of Sciences, Beijing, 10001, China.
G3 (Bethesda). 2015 Nov 12;6(1):141-8. doi: 10.1534/g3.115.024448.
Glyptosternoid fishes (Siluriformes), one of the three broad fish lineages (the two other are schizothoracines and Triplophysa), have a limited distribution in the rivers in the Tibetan Plateau and peripheral regions. To investigate the genetic mechanisms underlying adaptation to the Tibetan Plateau in several fish species from gradient altitudes, a total of 20,659,183-37,166,756 sequence reads from six species of catfish were generated by Illumina sequencing, resulting in six assemblies. Analysis of the 1,656 orthologs among the six assembled catfish unigene sets provided consistent evidence for genome-wide accelerated evolution in the three glyptosternoid lineages living at high altitudes. A large number of genes refer to functional categories related to hypoxia and energy metabolism exhibited rapid evolution in the glyptosternoid lineages relative to yellowhead catfish living in plains areas. Genes showing signatures of rapid evolution and positive selection in the glyptosternoid lineages were also enriched in functions associated with energy metabolism and hypoxia. Our analyses provide novel insights into highland adaptation in fishes and can serve as a foundation for future studies aiming to identify candidate genes underlying the genetic basis of adaptation in Tibetan fishes.
纹胸鮡鱼类（鲇形目）是三大鱼类谱系之一（另外两个是裂腹鱼类和高原鳅属鱼类），在青藏高原及其周边地区的河流中分布有限。为了研究几种来自不同海拔高度的鱼类适应青藏高原的遗传机制，通过Illumina测序从六种鲶鱼中产生了总共20,659,183 - 37,166,756条序列读数，从而得到了六个基因组组装结果。对六个组装的鲶鱼单基因集之间的1656个直系同源基因的分析，为生活在高海拔地区的三个纹胸鮡谱系在全基因组范围内的加速进化提供了一致的证据。相对于生活在平原地区的黄颡鱼，大量与缺氧和能量代谢相关功能类别的基因在纹胸鮡谱系中表现出快速进化。在纹胸鮡谱系中显示出快速进化和正选择特征的基因也在与能量代谢和缺氧相关的功能中富集。我们的分析为鱼类的高原适应提供了新的见解，并可为未来旨在鉴定西藏鱼类适应遗传基础的候选基因的研究奠定基础。
