广地龙特异性PCR分子鉴定

Specific Polymerase Chain Reaction Molecular Identification of Pheretima aspergillum(E. Perrier)

【目的】筛选出对广地龙具有特异性鉴别意义的PCR引物,建立一种快速、准确鉴别广地龙基原真实性的方法。【方法】收集药典收载的4种地龙原动物以及市场常见地龙混淆品6种,从Gen Bank数据库中下载有关蚯蚓的12Sr RNA基因序列,采用通用引物对10种样本PCR扩增后进行测序,依其序列间差异设计3对非保守区特异性引物,筛选对广地龙具有特异性扩增的引物。【结果】引物12St/12Sf对广地龙产生特异性扩增,当退火温度提升至64℃时,其反应表现出高度特异性,仅广地龙具有良好的单一扩增带,而其他样品在同样的条件下无扩增带。所得特异性引物在15种市售广地龙药材中验证结果良好,与传统形态学鉴定结果基本一致。【结论】引物12St/12Sf可作为广地龙物种鉴定的特异性标记物,可以实现广地龙近缘多个物种快速而又准确的鉴定,且不受实验材料的完整性、加工干燥等因素的影响。

Objective To screen out the polymerase chain reaction （ PCR） primers for specifically identifying Pheretima aspergillum （E. Perrier） , so as to establish a rapid and accurate method to identify the origin of Pheretima aspergillum. Methods Four kinds of earthworms recorded in pharmacopoeia and six kinds of their adulterants commonly seen in the market were collected. The 12SrRNA sequences related to earthworm were downloaded from GenBank database. PCR amplification for ten kinds of samples was performed using the universal primers, and then the products were sequenced. According to the differences between the above sequences, three pairs of specific primers in the non-conservative district were designed for identification of Pheretima aspergillum. Results High-specificity PCR amplification for Pheretima aspergillum with 12St/12Stf primer occurred when the annealing temperature was increased to 64℃, and only Pheretima aspergillum had single amplification strip, while no strips were found in the other adulterants under the same condition. The achieved specific primers could be well verified in 15 kinds of medicinal materials of earthworm purchased in the market, which had the same morphological features showed by the traditional identifying method. Conclusion With 12St/12Stf primer as a specific marker, the identifica tion of Pheretima aspergillum is rapid and accurate in related species of Pheretima aspergillum, and avoids the effect of some factors such as integrity of experimental materials and drying process.