DNA barcoding and its utility in commonly-used medicinal snakes / 中国中药杂志

Identification accuracy of traditional Chinese medicine is crucial for the traditional Chinese medicine research, production and application. DNA barcoding based on the mitochondrial gene coding for cytochrome c oxidase subunit I (COI), are more and more used for identification of traditional Chinese medicine. Using universal barcoding primers to sequence, we discussed the feasibility of DNA barcoding method for identification commonly-used medicinal snakes (a total of 109 samples belonging to 19 species 15 genera 6 families). The phylogenetic trees using Neighbor-joining were constructed. The results indicated that the mean content of G + C(46.5%) was lower than that of A + T (53.5%). As calculated by Kimera-2-parameter model, the mean intraspecies genetic distance of Trimeresurus albolabris, Ptyas dhumnades and Lycodon rufozonatus was greater than 2%. Further phylogenetic relationship results suggested that identification of one sample of T. albolabris was erroneous. The identification of some samples of P. dhumnades was also not correct, namely originally P. korros was identified as P. dhumnades. Factors influence on intraspecific genetic distance difference of L. rufozonatus need to be studied further. Therefore, DNA barcoding for identification of medicinal snakes is feasible, and greatly complements the morphological classification method. It is necessary to further study in identification of traditional Chinese medicine.

DNA barcoding of COI gene in some medicinal animals of Lacertilia / 中国中药杂志

To identify some medicinal animals of Lacertilia, in total 59 individuals belonging to 12 species 7 genera 3 families, we used the universal barcoding primers to sequence these species, compared with other homologous sequences (564 bp) obtaining from the GenBank and finally constructed phylogenetic trees using Neighbor-joining, Maximum parsimony and Bayesian inference, respectively. As a result, the mean content of G + C (46.5%) was lower than that of A + T (53.5%). As calculated by Kimera-2-parameter model, the whole individuals mean distance for interspecies and intraspecies was 35. 5% and 1.7%, respectively. The mean distance for interspecies was 21 times as much as that for intraspecies. The mean distance for intraspecies of Gekko swinhonis, Hemidactylus frenatus and G. gecko was greater than 2%, respectively. Further analyses suggested that geographical groups of the three species might be of different subSpecies, even species. Of course, incorporating morphological characters and other unlinked genetic markers in future studies will offer further insights into the divergence. On the basis of phylogenetic trees constructed by COI, our results indicated that the taxonomy of the category (family, genus, and species) by DNA barcoding is consistent with morphological characters. Therefore, DNA barcoding is a useful tool for both identification and phylogeny of medicinal animals of Lacertilia, particularly for nonprofessor identifying authentication of Chinese crude drugs of these species.