9种拟步甲16S rDNA部分序列及其亲缘关系

测定了9种拟步甲的16S rDNA部分基因序列,并与GenBank中的1种步甲的基因序列作同源性比较,计算其核苷酸使用频率并构建了分子系统树.在获得的435 bp的序列中,A+T约占74.4%,颠换(transversion)取代的速率大于转换(transition)取代的速率,其中277个核苷酸位点存在变异.结果表明:属内种间的碱基序列差异范围为3.4%～6.2%;族内属间为9.4%～11.0%;科内族间为10.8%～17.7%;科与科间的差异达到46.7%～50.3%.分子系统树表明:拟步甲科为一单系群,其中琵甲族较为进化,漠甲族与漠王族相对原始;琵甲族与土甲族的亲缘关系较近;漠甲族、漠王族与鳖甲族的亲缘关系较近.本结果与传统的分类观点相吻合.

16S rDNA Sequences and Relationships of Nine Darkling Beetles Species

Based on the 16S rDNA of nine darkling beetles species belonging to five tribi of family Tenebrionidae from China and keyed to one species of carabid-beetles from GenBank,the homologus sequences were compared. The frequency of nucleotide was calculated and the molecular phylogenetic tree is constructed by MEGA microsoft. In the 435 bp fragment of mitochondrial 16S rDNA,A + T was about 74.4% and 277 nucleotide sites were substituted. The variation rate of transversion was larger than transition. The results showed that the ranges of the 16S rDNA nucleotide divergence,among species of a genus,among genera of a tribe,among tribi of a family and between different families were 3.4% ～6.2%,9.4%～11.0%,10.8%～17.7% and (46.7%)～50.3%,respectively. The molecular phylogeny trees indicated that the ingroup(Tenebrionidae)were clustered together as one clade. Blaptini had closer relations with Opatrini as well as being the more evolutional group. Pimeliini and Platyopini were the more ancestral groups and had closer relations with Tentyriini in Tenebrionidae,which is consistent with traditional classification.