Marine Biotechnology Division, ICAR-Central Marine Fisheries Research Institute, Ernakulam North P O, Kochi, Kerala, 682018, India.
Mangalore University, Mangalagangotri, Mangalore, Karnataka, 574199, India.
Sci Rep. 2022 Apr 4;12(1):5642. doi: 10.1038/s41598-022-09636-5.
Carangids are abundant and commercially important marine fish that contribute to a significant portion of the fisheries in many parts of the world. In the present study, we characterized the complete mitogenome of the Indian scad, Decapterus russelli and performed a comprehensive comparative mitogenomic analysis of the family Carangidae. The comparative mitogenomics provided valuable insights into the structure, variability, and features of the coding and non-coding regions that evolved across species over millions of years. The structural features of tRNAs revealed changes in the frequency of mismatched and wobble base pairs, which is reflected in the base composition of H and L strands. The highly conserved sequence motif of the mTERF binding site in carangids over the ~ 400 MYA of their divergence demonstrated the functional importance of these sites. The control region of carangids was characterized by the presence of discontinuous repeat units with a high rate of sequence divergence in the form of base substitutions, insertions, and deletions. The maintenance of secondary structures in the control region independent of the rapid evolution of primary structure suggested the effect of selective constraints on their maintenance. Maximum likelihood (ML) and Bayesian inference (BI) phylogeny revealed a similar topology consistent with previous taxonomic studies. The extant carangids diverged through the evolutionary events experienced during the Cretaceous, Paleogene, and Neogene periods.
鯵科鱼类是丰富且具有商业重要性的海洋鱼类，对世界许多地区的渔业做出了重要贡献。在本研究中，我们对印度马鲛 Decapterus russelli 的完整线粒体基因组进行了特征描述，并对鯵科鱼类进行了全面的比较线粒体基因组分析。比较线粒体基因组学为编码和非编码区域的结构、变异性和特征提供了有价值的见解，这些特征在数百万年的物种进化过程中发生了变化。tRNA 的结构特征揭示了错配和摆动碱基对频率的变化，这反映在 H 和 L 链的碱基组成中。在 Carangidae 分化的 4 亿多年中，mTERF 结合位点的高度保守序列模体表明了这些位点的功能重要性。Carangids 的控制区的特征是存在不连续的重复单元，其形式为碱基替换、插入和缺失，导致序列高度分化。控制区中二级结构的维持与一级结构的快速进化无关，这表明选择压力对其维持的影响。最大似然（ML）和贝叶斯推断（BI）系统发育揭示了与先前分类学研究一致的相似拓扑结构。现存的鯵科鱼类通过白垩纪、古近纪和新近纪经历的进化事件而分化。
