数种蜥蜴亚目药用动物DNA条形码分类探讨

该研究选取数种蜥蜴亚目药用动物为研究对象,应用DNA条形码通用引物扩增测序,并与GenBank收录的共3科7属12种59个体的同源序列(564 bp)进行比对分析,采用邻接法、最大简约法和贝叶斯推断法分别构建分子系统发育树.结果表明,该片段的G+C平均量为46.5％,低于A+T平均量(53.5％).基于Kimura双参数模型计算,所有个体的种内遗传距离平均值为1.7％,种间遗传距离平均值为35.5％,种间平均遗传距离是种内的21倍.无疣壁虎、疣尾蜥虎和大壁虎的种内平均遗传距离均大于2％,进一步分析表明这些种的地理群体间的遗传分化可能均已达到亚种甚至种的水平,当然还需要结合形态、更多分子标记等分析才能定论.基于COI基因片段序列构建的系统发育树表明,DNA条形码在科、属和种水平的分类鉴定与传统方法所得结果一致.因此,DNA条形码用于蜥蜴亚目药用动物物种间的鉴定是可行的,特别是对于非专业人员鉴定相关类群药材真伪具有一定应用价值.

DNA barcoding of COI gene in some medicinal animals of Lacertilia

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 non-professor identifying authentication of Chinese crude drugs of these species.