Norwegian Institute of Bioeconomy Research (NIBIO), Division of Environment and Natural Resources, Svanhovd, N-9925 Svanvik, Norway.
Norwegian Institute of Bioeconomy Research (NIBIO), Division of Forestry and Forest Resources, P.O. Box 115, N-1431 Ås, Norway.
Genomics. 2022 Mar;114(2):110297. doi: 10.1016/j.ygeno.2022.110297. Epub 2022 Feb 5.
We determined the mitogenome of Cyclopterus lumpus using a hybrid sequencing approach, and another four closely related species in the Liparidae based on available next-generation sequence data. We found that the mitogenome of C. lumpus was 17,266 bp in length, where the length and organisation were comparable to those reported for cottoids. However, we found a GC-homopolymer region in the intergenic space between tRNA and ND1 in liparids and cyclopterids. Phylogenetic reconstruction confirmed the monophyly of infraorders and firmly supported a sister-group relationship between Cyclopteridae and Liparidae. Purifying selection was the predominant force in the evolution of cottoid mitogenomes. There was significant evidence of relaxed selective pressures along the lineage of deep-sea fish, while selection was intensified in the freshwater lineage. Overall, our analysis provides a necessary expansion in the availability of mitogenomic sequences and sheds light on mitogenomic adaptation in Cottoidei fish inhabiting different aquatic environments.
我们采用混合测序方法测定了圆鳍鱼科的圆鳍鱼的线粒体基因组，并基于现有的下一代测序数据，测定了另外四种亲缘关系密切的 Liparidae 物种的线粒体基因组。我们发现，圆鳍鱼的线粒体基因组长 17266bp，其长度和组织与报道的 Cottoidei 鱼类相似。然而，我们在 Liparidae 和 Cyclopteridae 之间的 tRNA 和 ND1 之间的基因间隔区发现了一个 GC- 同聚物区域。系统发育重建证实了亚目内的单系性，并有力地支持了圆鳍鱼科和脂鲤科之间的姐妹群关系。纯化选择是 Cottoidei 线粒体基因组进化的主要力量。在深海鱼类的谱系中，有明显的证据表明选择压力放松，而在淡水谱系中，选择压力加剧。总的来说，我们的分析为线粒体基因组序列的可用性提供了必要的扩展，并揭示了栖息在不同水生环境中的 Cottoidei 鱼类的线粒体基因组适应。
