Sun Cheng-He, Liu Hong-Yi, Xu Nan, Zhang Xiao-Li, Zhang Qun, Han Bo-Ping
Department of Ecology, Jinan University, Guangzhou, China.
College of Biology and the Environment, Nanjing Forestry University, Nanjing, China.
Front Genet. 2021 Feb 1;12:627402. doi: 10.3389/fgene.2021.627402. eCollection 2021.
The Characidae family contains the largest number of tropical fish species. Morphological similarities make species identification difficult within this family. Here, the complete mitogenomes of two Characidae fish were determined and comparatively analyzed with those of nine other Characidae fish species. The two newly sequenced complete mitogenomes are circular DNA molecules with sizes of 16,701 bp (; MT484069) and 16,710 bp (; MT484070); both have a highly conserved structure typical of Characidae, with the start codon ATN (ATG/ATT) and stop codon TAR (TAA/TAG) or an incomplete T--/TA-. Most protein-coding genes of the 11 Characidae mitogenomes showed significant codon usage bias, and the protein-coding gene was found to be a comparatively slow-evolving gene. Phylogenetic analyses via the maximum likelihood and Bayesian inference methods confirmed that and belong to the family Characidae. In all Characidae species studied, one genus was well supported; whereas other two genera showed marked differentiation. These findings provide a phylogenetic basis for improved classification of the family Characidae. Determining the mitogenomes of and improves our understanding of the phylogeny and evolution of fish species.
脂鲤科包含的热带鱼种类最多。形态学上的相似性使得该科内的物种鉴定很困难。在此，测定了两种脂鲤科鱼类的完整线粒体基因组，并与其他9种脂鲤科鱼类的线粒体基因组进行了比较分析。新测序的两个完整线粒体基因组是环状DNA分子，大小分别为16,701 bp（；MT484069）和16,710 bp（；MT484070）；两者都具有脂鲤科典型的高度保守结构，起始密码子为ATN（ATG/ATT），终止密码子为TAR（TAA/TAG）或不完整的T--/TA-。11种脂鲤科线粒体基因组的大多数蛋白质编码基因显示出明显的密码子使用偏好，并且发现蛋白质编码基因是一个进化相对缓慢的基因。通过最大似然法和贝叶斯推断法进行的系统发育分析证实，[具体物种名称1]和[具体物种名称2]属于脂鲤科。在所研究的所有脂鲤科物种中，一个属得到了很好的支持；而其他两个属则表现出明显的分化。这些发现为改进脂鲤科的分类提供了系统发育基础。测定[具体物种名称1]和[具体物种名称2]的线粒体基因组增进了我们对鱼类物种系统发育和进化的理解。
