线粒体12S与COI条形码对海洋鱼类的鉴定差异

Differences in the Identification of Marine Fish by Mitochondrial 12S and COI Barcodes

本研究基于145种常见海洋鱼类比较了使用12S与COI条形码鉴定物种的差异。结果如下:(1)145种鱼类共测得12S序列528条,所测鱼类基于12S条形码的种内遗传距离在0~0.0068之间,最小种间遗传距离为0~0.4162;有7种鱼类的种内遗传距离过大(大于0.0055),且NJ系统发生树中存在不同鱼类聚于同一组内,种与种之间不分界的现象。(2)145种鱼类共测得COI序列686条,所测鱼类基于COI条形码的种内遗传距离在0~0.0049之间,种间遗传距离均大于0.02,且至少为种内遗传距离的15.28倍;NJ系统发生树显示,各鱼类聚于不同组内,种与种之间分界明显。结果表明,基于12S基因的鱼类DNA条形码的物种鉴定存在物种注释假阴性或假阳性风险,应尽可能考虑使用COI条形码,以提高物种鉴定的准确性。

The differences between 12S and COI barcoding in species identification based on 145 common marine fish species were compared.The results were as follows:1)a total of 528 sequences of 12S were detected in 145 species.The intraspecific genetic distance of all the fish based on 12S barcode ranged from 0 to 0.0068,the minimum interspecific genetic distance ranging from 0 to 0.4162 and the intra-species genetic distances of 7 species were too large(0.005 5).In NJ phylogenetic tree,some interspecific fishes clustered in the same group without demarcation between species.2)A total of 686 sequences of COI were detected.The intraspecific genetic distance of all the fish based on COI barcoding ranged from 0 to 0.0049,and the interspecific genetic distance was above 0.02 and at least 15.28 times of the intraspecific genetic distance.NJ phylogenetic tree showed that interspecific fishes clustered in different groups,and the boundary between species was obvious.The results of this study suggest that fish DNA barcoding studies based solely on 12S gene have the risk of false negative and/or false positive species annotation,and the use of barcoding fragments such as COI should be considered whenever possible to improve the accuracy of species annotation.