嗡蜣螂属Onthophagus十二种蜣螂线粒体COⅠ基因的DNA条形码研究

Application of DNA barcoding to mtDNA COⅠ genes in 12 dung beetle (Onthophagus) species

对嗡蜣螂属Onthophagus12种蜣螂的线粒体COI基因3’端部分序列（731bp）进行了比较，结果显示，C01序列的变异位点213个，简约信息位点167个。碱基替代主要发生在第3位点（64次），占替代总数的83．12％。除掘嗡蜣螂0．fodiens与婪嗡蜣螂0．1enzi小于2％外，其余种问遗传距离在8．1％～15．8％之间，种内遗传距离为0～0．2％。单倍型多样性（Hd）和核苷酸序列多样性（Pi）分别为0．944±0．030和0．105184-0．0045。滑动窗口分析表明，可变位点频率在240～290bp、675bp附近较高。NJ树聚类结果与传统形态学分类相吻合：外群代表种分化最早，种间聚成一分支，种内个体优先聚集种下。本文认为COl基因适合作为嗡蜣螂属物种鉴定的DNA条形码。

The DNA sequences of 12 dung beetle species from the genus Onthophagus were compared using a molecular marker of the 3＇end fragment（731 bp） of the mitochondrial DNA COI gene. 213 variable sites and 167 parsimony information sites were identified. Base substitution mainly occurred on the third codon （64 times） , accounting for 83. 12% of all substitutions. Interspecific divergence spanned from 8. 1% to 15. 8% , with the exception of the genetic distance between O. fodiens and O. lenzi which was below 2% , and intraspecific variation varied from 0 to 0.2%. Haplotype diversity （Hd） and nucleotide diversity （Pi） were 0. 944 _＋ 0. 030 and 0. 10518 _＋ 0. 0045, respectively. Two sliding windows analyses demonstrated that the frequency of variable sites for all sequences located within 240 - 290 bp and approximately 675 bp was high. NJ phylogenetic tree revealed that molecular clusters was consistent with the traditional taxonomy based on morphological characteristics. The outgroup lineages separate first from the phylogenetic tree. Interspecific specimens clustered in one branch with intraspecific specimens clustered according to species and that branch. These results indicate that COI gene barcoding can reliably identify species of the genus Onthophagus.