基于线粒体全基因组结构的鲳属鱼类分子分类研究

Study on molecular taxonomy of genus Pampus based on complete mitochondrial genome structure

为明确鲳属鱼类的线粒体全基因组序列结构、寻找有效的种间鉴别分子标记,并剖析其系统发育信息,从而为鲳属鱼类的分类学、进化遗传学和种质鉴定提供参考依据,测定了鲳属5种鱼类(中国鲳Pampus chinensis、灰鲳P.cinereus、银鲳P.argenteus、珍鲳P.minor、翎鲳P.punctatissimus)的线粒体全基因组序列,并结合NCBI数据库中已有的鲳属鱼类线粒体全基因组序列进行分析。结果显示:1)鲳属线粒体基因组全序列长度在16551 bp到18062 bp之间,其基因组结构与大多数硬骨鱼类一致;比较特别的是,银鲳和镰鲳具有两个tRNA;结构,珍鲳出现ND1基因重排以及两个重复的D-loop结构。2)银鲳与镰鲳的D-loop区出现重复CSB3结构,灰鲳与翎鲳D-loop区出现重复TAS结构。3)ND2基因条形码及其微型条形码均可将鲳属鱼类区分开,可作为有效的鲳属鉴别分子标记。4)东海区的银鲳与镰鲳应为同一物种,灰鲳可能为翎鲳的同物异名。

Pampus is a group of economically important fishes widely distributed in the Western Pacific-Indian Ocean,including the coast of China,Indian Ocean,Arabian Gulf and North Sea.Among them,P.argenteus is one of the most popular marine fishes in China because of delicious taste and high nutritional value.Thus,it is loved by consumers and plays an important role in China’s marine fisheries.Since the establishment of the genus Pampus,its species classification has always been the research focus of many scientists,and it is also the basis for other studies such as population genetics and systematics on the genus Pampus.During the initial stage,the research was mainly based on morphological characteristics.However,the morphological difference of the genus Pomfret(former genus name of Pampus)was very small.It was difficult to distinguish them,and there were differences in morphological description of pomfrets in different studies,which brought great difficulties to the classification of Pampus.Till now,there has been still lack of an unified and efficient classification standard.In recent decades,molecular biology has been applied to the classification of Pampus.Scientists mainly used mitochondrial genes to identify and classify Pomfret.In order to make clear the complete mitochondrial genome structure of genus Pampus,to find effective molecular markers for interspecific identification,clarify its phylogenetic information,and to provide references for the taxonomy,evolutionary genetics,and germplasm identification analysis of genus Pampus,we sequenced the complete mitogenomes of five Pampus species and analyzed all the mitochondrial genome sequences together with other existing sequences of Pampus downloaded from GenBank databases.Results showed that:1)Lengths of mitochondrial genomes of genus Pampus were from 16551 bp to 17069 bp.Mitochondrial genome composition and order was basically consistent with other teleost fishes.P.argenteus and P.echinogaster had two tRNA;structures,while ND1 gene rearrangement and repeated D-loop structure were found in mitogenome of P.minor.2)Mitochondrial control region sequence of P.argenteus and P.echinogaster included repeated CSB3 structure,and the control region sequence of P.cinereus and P.punctatissimus included repeated TAS structure.3)Both DNA barcodes based on the ND2 gene and their mini-barcodes can effectively identify Pampus species.4)P.argenteus and P.echinogaster in the East China Sea were possibly the same species,and P.cinereus might be a synonym of other species.And further evidences are needed for the study of genus Pampus.