摘要： 本实验对来自湖北武汉市南湖，湖北咸宁阳武干渠，湖北鄂州池塘，江西南昌青岚湖，安徽巢湖，江苏宜兴太湖6个地理种群的铜锈环棱螺（Bellamya aeruginosa）的细胞色素c氧化酶亚基I（COI）基因片段的核苷酸序列进行了分析，以探讨COI的核心片段序列在铜锈环棱螺种群遗传结构和分子系统发育研究中的应用价值，为进一步利用这一序列鉴定我国环棱螺种质资源，种群遗传结构，分类阶元和遗传多样性提供基础依据。测序结果表明，所有铜锈环棱螺扩增片段长度均为709bp，序列A+T含量（0.664-0.684）明显高于G+C含量。铜锈环棱螺6个地理种群种群间共有变异位点（Variable sites）24个，在核酸序列中发现3种变异类型，其中转换20次，颠换3次，转换/颠换1次。其中简约信息位点（Parsimony informative sites）13个，单一多态位点数（Singleton polymorphic sites）为10，核苷酸多态性（Pi）为0.015，平均核苷酸差异数（K）10.933。同义替换（Synonymous Substitutions）和非同义替换（NonSynonymous Substitutions）位点数为158.17和549.83。以COI基因片段序列为标记，用Corbicula fluminalis和Taylorconcha insperata作为外群，并将其它已公布的部分环棱螺（Bellamya sp., B.capillata, B.pagodiformis, B.mweruensis, B.crawshayi, B.trochlearis, B.rubicunda, B.unicolor, B.jeffreysi, B.bengalensis），田螺（Viviparidae sp.,V. ater, V.contectus）和其他螺类（Theodoxus transversalis, Nerita costata, Pseudamnicola exilis）为内群，构建了环棱螺的系统发生树。其拓扑结构显示6个地理种群的铜锈环棱螺聚为一个单元，然后与其它环棱螺和田螺聚为一支，而与其它的螺类形成不同分支，与外群相区别，其结果与传统的形态分类结果基本相符。说明COI基因适合作为环棱螺种群遗传结构和系统发生研究的分子标记。
职称论文发表期刊关键词： 铜锈环棱螺；COI；种群遗传结构；系统发育
Abstract： In this experiment, a nucleotide sequence analysis of mitochondrial cytochrome coxidase subunit I (COI) gene fragment sequence was conducted among six geograph -ic populations of Bellamya aeruginosa of Nanhu in Wuhan city, YangWu canal in Xianning city, the pond in Ezhou city, QingLan lake in Nanchang city, Chaohu lake, Taihu in Yixing to determine the utility of COI fragment sequences in population gen -etic structure and molecular phylogenetic of Bellamya aeruginosa, and for further use of this sequence in species identification. The results showed that nucleotide sequencees of 709 bp in length were obtained from the COI in all Bellamya aeru -ginosa, with A+T contents from 66.2% to 68.4%, which obviously higher than G+C contents. Analysis of sequence variation at the COI gene across Bellamya aeruginosa in 6 geographical populations revealed 24 variable sites and three types of variant which transition 20, transversion 3 and transition / transversion 1. The parsimony informative sites are 13, singleton polymorphic sites are 10. The single nucleotide polymerp hism (Pi) is 0.015. The average number of nucleotide differences (K) is 10.933. Synon -ymous substitutions and nonsynonymous substitutions number is 158.17 and 549.83. The phylogenetic tree of Bellamya was reconstructed by using COI gene sequences, using Corbicula fluminalis and Taylorconcha insperata as outgroup, other Bellamya (Bellamya sp. B.capillata, B.pagodiformis, B.mweruensis, B.crawshayi, B.trochlearis, B.rubicunda, B.jeffreysi, B.unicolor, B.ngalensis), and (Viviparidae sp. V.ater, V.contectus) and other Theodoxus, transversalis, Nerita costata, Pseudamnicola exilis which have been published in Genebank as ingroup. Topologies trees indicated that six geographic populations of Bellamya aeruginosa formed a monophyletic group and then with other Bellamya and Viviparidae, but compared with other snails form different clades, which was consistent with the tree based on morphological characters. This result reveals that the COI gene was an appropriate marker for studies of phylogeny and phylogeography of the Bellamya.
Keywords： Bellamya aeruginosa; COI; population genetic structure; phylogeny
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