Specific DNA mini-barcoding for identification of Gekko gecko and its products

Abstract

Background: The dry body of the Tokay Gecko (Gekko gecko) is the source of a valuable traditional Chinese medicine, it is therefore listed as a Class II protected animal species in China. Due to increasing market demand and a declining supply of the species, a considerable number of adulterants have emerged in the market. Thus, it is necessary to establish an accurate and rapid method of identification for distinguishing G. gecko from its adulterants and for separating it from highly processed products. Methods: A total of 274 COI sequences were analyzed by using MEGA 5.0 software. Several specific primers were designed to amplify mini-barcode regions and identify G. gecko from its counterfeits and products. Results: 274 COI sequences of G. gecko and 15 adulterants species were analyzed. G. gecko could be distinguished from its adulterants through BLAST analysis, intra- and inter-specific distance analyses, and an NJ tree based on COI sequences. Two pairs of specific primers designed for this study, COISF2/COISR2 and COISF3/COISR3, amplified 200- and 133-bp fragments of the COI region, respectively, both of which were suitable for the identification of G. gecko and its adulterants. Furthermore, COISF3/COISR3 detected G. gecko in 15 batches of products. Conclusion: Therefore, the specific DNA mini-barcoding method developed here may be a powerful tool for the identification of G. gecko and counterfeits, and may also be used to distinguish G. gecko from its highly processed by-products.