口岸截获国内未见分布种褐小家鼠的DNA条形码鉴定

DNA barcoding identification of Mus cervicolor,a non recorded mouse species in China

目的利用DNA条形码技术对中山口岸从柬埔寨进口木薯干中截获的外部形态特征破坏严重的2只未知鼠样本进行种类鉴定。方法提取截获鼠样本的基因组DNA,采用动物线粒体细胞色素氧化酶Ⅰ(COⅠ)的通用引物LCO1490和HCO2198扩增目的片段。然后测序、序列分析,与NCBI中的序列进行比对,并选取NCBI中序列相似度高的部分序列构建NJ树。结果 2只鼠的DNA条形码序列相似度高达99.8%,与NCBI中褐小家鼠(Mus cervicolor)的序列相似性最高为98.5%;大于DNA条形码判断物种的相似度98%的阈值。经科技查新,确认为全国口岸首次截获的国内未见分布鼠种。结论利用DNA条形码技术对截获鼠类进行鉴定,鉴定结果为褐小家鼠,为国内未见分布种。DNA条形码能克服传统物种鉴定依靠完整的外部形态的局限,并能克服鉴定资料、专业人员缺乏等因素带来的困难,有效提高外来物种的种类鉴别力和准确度。

Objective DNA barcoding techniques were employed to identify the unknown mouse species intercepted from the dry cassava imported from Cambodia at Zhongshan port, whose morphology was damaged too badly to be identified. Methods Genomic DNA was extracted from the intercepted mouse. Target fragments were amplified with the universal primers LCO1490 and HCO2198 for the metazoan mitochondrial cytochrome oxidase Ⅰ （CO Ⅰ ）, PCR products were sequenced. The sequences were blasted in the NCBI. Results The sequence homology of the DNA barcode fragment between these two samples were 99.8%, and was more than 98.5% identical to the sequence of Mus cervicolor published in NCBI. Mus cervicolor is never recorded in China before, and it was the first time to intercept this species at the Chinese port according to the references. Conclusion The intercepted mouse was M. cervicolor identified with DNA barcodes, a non- recorded species in China. DNA barcoding techniques could break the restrictions of traditional species identification depending on undamaged morphological characteristics, can improve the ability to identify the exotic species, overcome the difficult in lack of identification references and experts.