五种色蟌Cyt b基因序列及其系统发育关系

以昆虫mtDNA的Cytb基因作为分子遗传标记,用其特异性引物进行PCR扩增及DNA测序,共获得蜻蜓目束翅亚目色蟌科4属5种及1外群的Cytb基因部分序列(576bp),该片段中碱基T,C,A,G的平均含量分别为31.6,21.6,31.4和15.4%,A+T平均含量为63%,明显高于G+C含量(37%)。密码子第3位点的A+T平均含量较高,为66.4%。碱基替换多发生在密码子的第3位点。以巨齿尾溪蟌Bayadera melanopteryx作为外群构建系统发育树,结果显示,绿色蟌属Mnais和单脉色蟌属Matrona是单系群,绿色蟌属是单脉色属、细色蟌属Vestalis及艳色蟌属Neurobasis的姐妹群,是较早分化出来的一个类群。

Analysis of cyt b gene sequences and molecular phylogeny of five species of Calopterygidae

The nucleotide composition and phylogenetic relationship among 5 species in Calopterygidae were studied based on the 576 bp sequences of cyt b gene. The results showed that the average contents of T, C, A and G are 31.6%, 21.6%, 31.4% and 15.4%, respectively. The content of A T (63%) is obviously higher than that of G C (37%), reaching up to 66.4 % at the third position of the codons. Nucleotide substitution most likely occurs at the third position. With Bayadera melanopteryx as outgroup, the phylogenetic trees shows that Mnais and Matrona are monophyletic, but Mnais, differentiated earlier from their common ancestor, is a sister group to Matrona, Vestalis and Neurobasis.