基于线粒体COⅠ基因序列的中国沿海缘边银鲈遗传多样性分析  

MtDNA COⅠsequence diversity of Gerres limbatus in coastal waters of China

作　　者：张玉宁 章群[1] 黄柏炎[1] 宫亚运 罗纯 黄志基 ZHANG Yuning;ZHANG Qun;HUANG Boyan;GONG Yayun;LUO Chun;HUANG Zhiji(College of Life Science and Technology,Jinan University,Guangzhou 510632,China)

机构地区：[1]暨南大学生命科学技术学院,广州510632

出　　处：《海洋渔业》2021年第2期129-136,共8页Marine Fisheries

基　　金：国家重点研发计划(2018YFD0900802)。

摘　　要：为了解中国沿海缘边银鲈(Gerres limbatus)的遗传背景,分析了9个地理群体140条样本线粒体细胞色素氧化酶Ⅰ(cytochrome oxidase subunitⅠ,COⅠ)基因5′端652 bp序列。结果发现14个变异位点,13个单倍型,其中有9个独有单倍型和4个共享单倍型,整体单倍型和核苷酸多样性都较低(H_(d)=0.276±0.050,π=0.0005±0.0001)。琼州海峡以东海域的遗传多样性(H_(d)=0.338~0.456,π=0.0006~0.0011)高于琼州海峡以西北部湾海区(H_(d)=0~0.295,π=0~0.0005)。单倍型网络图未出现明显谱系结构和地理结构。群体遗传分化系数F_(st)显示,硇洲群体与其他群体间出现不显著的中低度遗传分化(F_(st)=0.0773~0.1696,P>0.05),其他群体间分化不明显(F_(st)=-0.0415~0.0612,P>0.05),总体上群体间分化程度都不高。AMOVA分析显示,遗传变异绝大部分(95%以上)来源于群体内。中性检验结果显示,群体总体的Tajima’s D(-2.2549)和Fu’s F_(s)(-16.4725)结果均为显著性负值(P<0.01),核苷酸错配图呈现较为明显单峰,单倍型网络图呈典型星状结构,表明缘边银鲈历史上存在过种群扩张,扩张时期约为距今0.1304~0.0435百万年。由于总体单倍型多样性小于0.5,核苷酸多样性小于0.005,推测中国缘边银鲈种群曾经历过较为严重的瓶颈效应。宁德、硇洲群体的核苷酸多样性相对较高,应优先保护。北部湾各群体遗传多样性极低,需要采取措施避免遗传多样性下降。In order to contribute information on genetic background of Gerres limbatus in coastal waters of China,652 bp mtDNA COⅠsequences of 140 individuals from 9 geographic populations were analyzed.14 mutation sites were found and 13 haplotypes were identified,of which 9 were unique haplotypes and 4 were shared haplotypes.The overall haplotype and nucleotide diversity were low(H_(d)=0.276±0.050,π=0.0005±0.0001),of which genetic diversity of populations from the east part of the Qiongzhou Strait(H_(d)=0.338-0.456,π=0.0006-0.0011)was higher than those in the western Beibu Gulf(H_(d)=0-0.295,π=0-0.0005).Haplotype network diagrams did not show obvious genealogical and geographic structure.Genetic differentiation coefficicent(F_(st))showed that there was indistinctively low-middle genetic differentiation between Naozhou population and other populations(F_(st)=0.0773-0.1696).No obvious differentiation was found among other populations(F_(st)=-0.0415-0.0612).AMOVA analysis also showed that 95%population variation originated from within the group.The negative overall value of the neutrality test(Tajima’s D=-2.2549;Fu’s F_(s)=-16.4725)and a significant single peak in the nucleotide mismatch distribution were consistent with demographic expansion in the past,and deduced expansion time ranged from about 0.1304 to 0.0435 million years ago.Since the overall genetic diversity of the population was less than 0.5 and nucleotide diversity was less than 0.005,it was speculated that Gerres limbatus population in coastal waters of China had recently encountered a severe bottleneck effect.The nucleotide diversity of the Ningde and Naozhou populations was relatively high and had a conservation priority.As genetic diversity of populations in the Beibu Gulf was extremely low,measures should be taken to avoid further decline in genetic diversity.

关 键 词：缘边银鲈 COⅠ 遗传多样性 种群历史动态 

分 类 号：Q349[生物学—遗传学]