基于线粒体COI基因序列的智利竹䇲鱼遗传多样性分析

Population genetic analysis of Trachurus murphyi based on the mitochondrial cytbchrome oxidase subunit I gene in the high seas off Chile

利用线粒体COI序列作为遗传标记,分析智利外海(78°40′W^81°45′W、40°18′S^44°25′S)智利竹䇲鱼(Trachurus murphyi)遗传结构特征。分析6个采样点的216个个体,共检测到13个变异位点,4个简约信息位点,9个单变异位点,并定义了14种单倍型。6个采样点的单倍型多样性为(0.375±0.090)^(0.716±0.060),核苷酸多样性为0.00063~0.00169,AMOVA分析Fst值为0.00629,小于0.05,表明变异主要来自于群体内,且群体间无分化。与基于单倍型和群体间遗传距离构建的UPMGA树的结果共同说明该海域群体间无分化,且在智利外海水域具有广泛的分布带。Tajima’s D和Fu’s Fs中性检验结果表明,智利竹䇲鱼近期经历过群体扩张事件。

Chilean jack mackerel Trachurus murphyi is a typical warm-water oceanic pelagic fish.T.murphyi is widely distributed in the coastal waters of Peru and Chile and the high seas off Chile.It is one of the main marine economic fish in the world.In order to exploit and manage this resource scientifically,we made a study on genetic population structure of T.murphyi.Mitochondrial COI sequences were amplified by PCR and then used for genetic structure analysis.We analyzed population genetic population structure of T.murphyi(n=216)collected from six sampling locations in the high sea waters off Chile(78°40′W-81°45′W、40°18′S-44°25′S),which were captured from April to June in 2014.In the study,a total of 216 individuals were collected from six different localities.A 624 bp mitochondrial COI sequence was amplified by PCR,and then used for genetic structure analysis.We detected a total of 13 variable sites,including 4 parsimony informative sites and 9 single variable sites,and defined 14 haplotypes.Haplotype diversity index ranged from(0.375±0.090)to(0.716±0.060),and nucleotide diversity index was 0.00063-0.00169.AMOVA indicated that the genetic differences between six locations were low(Fst=0.00629,P<0.05),and the results of the UPMGA tree together showed that there was no differentiation between groups in the high sea waters off Chile.The neutrality test(Tajima’s D and Fu’Fs)suggested that T.murphyi had undergone a recent population expansion.Informed management and conservation of marine fish resources must integrate results from molecular population genetic studies.Our results will be beneficial to inform the sustainble exploitation and conservation of T.murphyi resources.