基于COI和16S rRNA基因片段鉴定厦门海域的仔稚鱼

Molecular identification of fish larvae and juveniles based on COI and 16S rRNA barcoding in Xiamen coastal areas

本文基于线粒体细胞色素C氧化酶亚基I(COI)基因和16S rRNA基因片段对采集于厦门海域的仔稚鱼样品进行种类鉴定,探究其在仔稚鱼种类鉴定中的适用性。研究共获得64条COI基因序列和74条16S rRNA基因序列,通过序列比对,COI基因将仔稚鱼样品鉴定为26个种类,其中19个种类鉴定到种、6个鉴定到属、1个种类仅鉴定到科;16S rRNA基因将仔稚鱼样品鉴定为29个种类,其中23个种类鉴定到种、6个鉴定到属。COI基因的平均种内遗传距离为0.0015,平均种间遗传距离为0.1976,16S rRNA基因的平均种内遗传距离为0.0003,平均种间遗传距离为0.0892,COI和16S rRNA基因的平均种间遗传距离都为平均种内遗传距离的10倍以上,两者都可以进行有效的仔稚鱼种类鉴定。在基于COI和16S rRNA基因构建的系统进化树上,所有物种都分别单独聚为一支,同一个种类的不同个体都能聚在同一个分支,这些物种均能得到有效区分。以上结果表明,COI和16S rRNA基因均可以实现仔稚鱼的种类鉴定,两种基因结合使用可以提高仔稚鱼种类鉴定的准确性。

In order to improve the identification accuracy of fish larvae and juveniles,fish larvae and juvenile samples collected from Xiamen sea area were identified by DNA barcoding technology based on COI and 16S rRNA genes.A total of 64 COI gene sequences and 7416S rRNA sequences were obtained.By COI sequence alignment,samples were identified to 26 species,including 19 to the level of species,6 to the level of genera and 1 to the level of family.By 16S rRNA genes,samples were identified to 29 species,including 23 to the level of species,and 6 to the level of genera.The average intraspecific genetic distance of COI gene was 0.0015,the average interspecific genetic distance was 0.1976,the average intraspecific genetic distance of 16S rRNA gene was 0.0003,and the average interspecific genetic distance was 0.0892.The interspecific genetic distance of the two genes were more than 10 times of the intraspecific genetic distance,both of which could be used for the effective identification of fish larvae and juveniles.In the phylogenetic tree constructed based on COI and 16S rRNA genes,all species were clustered into independent branches,and different individuals of the same species could cluster in one branch,and these species could be effectively distinguished.These results indicate that both COI and 16S rRNA genes can realize the species identification of fish larvae and juveniles,and the combination of the two genes can improve the accuracy of species identification.