卵形鲳鲹线粒体COI基因全长序列的克隆与分析

摘要

根据近源物种线粒体序列的同源比对,在C0I基因上下游保守区域设计一对通用引物COF/COR.以卵形鲳鲹肌肉总DNA为模板,PCR扩增获得特异的DNA片段,经克隆、测序和比对证实该片段包含了卵形鲳鲹线粒体COI基因完整编码区1551bp.对5个个体分别测序后比对,发现卵形鲳鲹COI基因DNA序列在钦州湾种群个体间至少存在7个变异位点,使5个个体分别具有5种不同的单倍型.将卵形鲳鲹种内不同个体及鲹科其他物种的COI核酸序列进行比较分析,根据比对结果构建鲳鲹科各物种的系统进化树,支持鲹科下设四个亚科(鲹亚科,(师)亚科,鲳鲹亚科,鲹亚科)的分类系统.通过COI基因遗传距离计算发现,卵形鲳鲹种内不同地理种群个体间遗传距离为0.001 ～0.005,显著低于Hebert等所推荐的物种鉴定最小种间遗传距离2％,而鲹科不同物种间遗传距离大于0.044,与形态学分类一致,说明COI作为卵形鲳鲹DNA条形码应用是可行的.%Baaed on homology alignment of mitochondrial sequence from neighbor species, a pair of conserved primers were designed on the flanking region of Col gene. The PCR amplification product was cloned to PGEM-Teasy vector and sequenced. Blast on NCBI confirmed that the sequence contain whole 1551 bp ORF of Col gene. Alignment of sequence from 5 fishes of the same population revealed at least 7 variation sites , which formed 5 different genotypes. Based on the multiple alignment of COI sequences of Trachinotus ovatus and other Carangidae species, a phylogenetic tree was constructed which supported the idea that Carangidae could be classed into four subfamilies: Caranginae, Seriolinae, Trachinotinae and Chorineminae. Genetic distance among Trachinotus ovatus from different populations was 0.001 - 0.005, significantly lower than the distance between spices recommended by Hebert of 2 %. While the genetic distance among different Carangidae fishes spices were longer than 0.044, indicating that COI gene was a useful DNA barcoding for Trachinotus ovatus.