DNA条形码技术在蛇类鉴别中的应用

Application of DNA barcoding in the identification of snake

从NCBI中GenBank数据库下载蛇类细胞色素b基因(Cytb)序列7329条,以MT765098.1序列为标准进行对比和修剪,获得蛇类Cytb序列4665条。对蛇类Cytb序列进行核苷酸饱和度、遗传多样性、种内和种间遗传距离计算,构建系统发育树。结果表明,基于Kimura–2–Parameter模型,蛇类平均种内遗传距离为3.3%,普遍小于6.7%,而平均种间遗传距离为19.96%,普遍高于9.3%,说明蛇类物种间遗传距离存在较大差异。根据蛇类物种间遗传距离,识别出蛇类23个物种的亚种,Pareas和Hydrophis属物种含有复合体,Atractus dunni、A.iridescen和A.occidentali互为姐妹物种。

7329 sequences of snake cytochrome b gene(Cytb)were downloaded from GenBank database of NCBI and compared and pruned according to MT765098.1 sequence.We obtained 4665 snake Cytb sequences,and calculated the nucleotide saturation,genetic diversity,and intraspecific and interspecific genetic distance of Cytb sequences to construct phylogenetic trees.The results showed that,based on Kimura 2-Parameter model,the average intraspecific genetic distance of snakes was 3.3%and generally less than 6.7%.The average interspecific genetic distance is 19.96%,which is generally higher than 9.3%,indicating that there are great differences in genetic distance between species of snakes.According to the genetic distance between species,23 subspecies of snakes were identified.Pareas and Hydrophis contain composites,and Atractus dunni,A.iridescen and A.occidentali are sister species.