Abstract: Objective To identify and analyze the rodents captured in the farmland in Xinhui district, Jiangmen, Guangdong province, China, using DNA barcoding technology, and to lay a foundation for the diversity study of murine-like animals and rodent prevention and control. Methods Forty-five rodents captured in the farmland in Xinhui district, Jiangmen, Guangdong province, in December 2017, were enrolled as study subjects. Their genetic DNAs were extracted and amplified for mitochondrial cytochrome c oxidase subunit I gene fragments using consensus primers. The gene fragments were sequenced and the results were subjected to sequence homology analysis using BLAST in the National Center for Biotechnology Information. The molecular evolutionary tree was constructed by the neighbor-joining method. Genetic distance was calculated based on a two-parameter model. Results Specific gene fragments of the forty-five samples were obtained by PCR amplification. Four species of rodents (Rattus losea, R. tanezumi, R. norvegicus, and R. andamanensis) were identified through BLAST comparison. Thirty-seven samples had identification results identical to the morphological identification (R. losea), and eight samples had erroneous morphological identification results, among which five were reidentified as R. tanezumi, two were reidentified as young R. norvegicus, and one was reidentified as R. andamanensis, according to the review of the initial results. A total of 131 mutation sites were identified through alignment and analysis of the 45 sequences, and 12 different haplotypes were identified through haplotype analysis. The intraspecific genetic distance of R. losea was 0-1.2%, the interspecific genetic distance was 7.1%-11.6%, and the mean genetic distance was 10.1%±0.7%. The NJ tree showed that individuals of the same rodent species were clustered into one branch with a 100% support rate, which could distinguish among different rodent species. Conclusion The DNA barcoding technology can effectively distinguish between related species with similar morphology and correct the erroneous results of morphological identification.

Key words: Rodent, DNA barcoding, Cytochrome c oxidase subunit Ι gene

摘要： 目的 应用DNA条形码技术对广东省江门市新会区农田捕获的鼠类进行种类鉴定和分析，为研究鼠形动物的多样性及鼠害防治奠定基础。方法 以2017年12月在广东省江门市新会区农田捕获的45只鼠为研究对象，分别提取鼠基因组DNA，采用通用引物扩增线粒体细胞色素C氧化酶亚基Ⅰ（COⅠ）基因片段并进行测序，将测序结果在美国国立生物技术信息中心中进行BLAST序列同源性比对，采用邻接法构建分子进化树，基于双参数模型计算遗传距离。结果 45只鼠样本均能通过PCR扩增出特异性基因片段，通过BLAST比对共鉴定出4种鼠（黄毛鼠、黄胸鼠、褐家鼠和黑缘齿鼠），37只鼠样本与形态学鉴定结果一致，为黄毛鼠；8只鼠样本存在形态鉴定错误，经复核，其中5只鼠重新鉴定为黄胸鼠，2只为幼年褐家鼠，另外1只为黑缘齿鼠。对45条序列进行比对分析发现有131个变异位点，单倍型分析结果显示有12个不同的单倍型。黄毛鼠种内遗传距离为0~1.2%，不同鼠种间遗传距离为7.1%~11.6%，平均遗传距离为（10.1±0.7）%，分子进化分析结果显示，同一种鼠类的个体聚为一支，支持率均为100%，能区分不同鼠种。结论 DNA条形码技术能够有效区分形态相似的近缘种，纠正形态学鉴定中的错误。

关键词: 鼠类, DNA条形码, 细胞色素C氧化酶亚基Ⅰ基因