基于多个线粒体序列的中韩俄沿海不同地理群体刺参的遗传多样性及种群结构分析

Genetic diversity and population structure of different geographical populations of sea cucumber (Apostichopus japonicus) from China, South Korea and Russia based on mitochondrial genes

关键词:  刺参  16S rDNA  COⅠ  D-loop  遗传多样性

Key words:  Apostichopus japonicus  16S rDNA  D-loop  COⅠ  Genetic diversity

摘要:

为评价不同海域不同体色特征刺参群体的遗传结构，本研究采用PCR技术扩增了中国、韩国和俄罗斯沿海8个刺参(Apostichopus japonicus)群体的16S rDNA、COⅠ和D-loop序列。根据所获得的16S rDNA、COⅠ和D-loop序列分析这8个群体的遗传多样性和遗传进化关系。结果显示，16S rDNA、COⅠ和D-loop序列长度分别为543 bp、656 bp和509~527 bp。16S rDNA序列中共检测到16个多态位点，16种单倍型，单倍型多样性指数为0.629，核苷酸多样性指数为0.0016，平均核苷酸差异数0.880。COⅠ序列共检测到62个多态位点，38种单倍型，单倍型多样性指数为0.958，核苷酸多样性指数为0.0073，平均核苷酸差异数为4.796。D-loop序列共检测到200个多态位点，61种单倍型，单倍型多样性指数为0.922，核苷酸多样性指数为0.0157，平均核苷酸差异数为6.834。3个线粒体片段对于不同群体的遗传多样性检测结果显示，D-loop和COⅠ序列的多态位点数、单倍型数和核苷酸多样性均显著高于16S rDNA序列，更适用于同一物种不同群体遗传结构的解析。韩国浦项地区3个群体遗传多样性最高，这可能与其所处地理位置洋流影响有关。利用COⅠ基因对采自浦项的3种体色刺参进行遗传分化分析，遗传分化系数Fst<0.05，不存在遗传分化。对所采集的群体构建的系统进化树结果显示，青岛海参群体与烟台海参群体聚为一支，再与韩国群山黑参群体聚为一支，然后与韩国木浦黑参群体聚在一起，向外依次为俄罗斯群体及韩国浦项的3个群体，不同种群的遗传结构受洋流影响最大，其次跟其地理分布有关。

Abstract:

In order to explore the genetic structure of sea cucumber populations with different body color characteristics in different sea areas, 16S rDNA, COⅠ and D-loop gene sequences of eight populations of sea cucumber (Apostichopus japonicus) from China, Korea and Russia were amplified by PCR. Genetic diversity and evolutionary relationship of the 8 populations were analyzed by 16S rDNA, COⅠ and D-loop gene sequences from 80 samples. The results showed that the sequence lengths of 16S rDNA, COⅠ and D-loop genes were 543 bp, 656 bp and 509~527 bp, respectively. There were 16 polymorphic loci and 16 haplotypes in the 16S rDNA sequence, the haplotype diversity index was 0.629, the nucleotide diversity index was 0.0016, and the average nucleotide diversity was 0.880. A total of 62 polymorphic loci and 38 haplotypes were detected in the COⅠ sequence, the haplotype diversity index was 0.958, the nucleotide diversity index was 0.0073, and the average nucleotide diversity was 4.796. A total of 200 polymorphic loci and 61 haplotypes were detected in the D-loop sequence. The haplotype diversity index was 0.992, the nucleotide diversity index was 0.0157, and the average nucleotide diversity was 6.834. The results showed that the polymorphic loci, haplotypes and nucleotide diversity of D-loop and COⅠ sequences were significantly higher than those of 16S rDNA sequences, which were more suitable for the analysis of genetic structure in different populations of the same species. The genetic diversity of the three populations was the highest in the Posco area of South Korea, which may be related to the influence of ocean currents. The COⅠ gene was used to analyze the genetic differentiation of three body color sea cucumbers collected from Posco, the genetic differentiation coefficient Fst was less than 0.05, and there was no genetic differentiation. The results of phylogenetic tree construction using COⅠ gene showed that the Qingdao and Yantai sea cucumber population were clustered into one branch, then the Korean Mokpo black sea cucumber population clustered into one branch, from the inner outward are successively the Russian population and the Korea Posco population. The results showed that the populations with different body colors were poorly differentiated, and the genetic distances and clustering of different populations had the strongest correlation with their geographical distribution.