基于COⅡ基因序列的斑腿蝗科部分亚科的分子系统学研究

Molecular phylogeny of some subfamilies of Catantopidae(Orthoptera:Caelifera:Acridoidea)in China based on partial sequence of mitochondrial COⅡ gene

采用PCR产物直接测序法测定了斑腿蝗科10个亚科16属22种的COⅡ基因585bp的片段,对序列的碱基组成进行了分析,并评估了数据集的系统发育信号;最后,以癞蝗科的肃南短鼻蝗作为外群,采用NJ法、MP法、ML法以及贝叶斯推论法构建了系统树,以解决这些物种所代表的亚科之间的系统发育关系。结果表明:22种斑腿蝗科昆虫的COⅡ基因序列碱基组成表现强烈的A+T含量偏向性。对COⅡ基因585bp序列片段构成的全数据组和根据密码子不同位点划分的密码子第一、第二和第三位点数据组的系统发育信号分析显示,所有数据组都具有一定的系统发育信息。在4种方法得到的合一树中发现:(1)星翅蝗亚科、刺胸蝗亚科、黑背蝗亚科、斑腿蝗亚科的亲缘关系较近;(2)卵翅蝗亚科与稻蝗亚科亲缘关系较近,建议卵翅蝗亚科似乎应归入稻蝗亚科中,板胸蝗亚科与这两个亚科的关系较近;(3)黑蝗亚科和秃蝗亚科似乎应合并为一个亚科;(4)切翅蝗亚科的4个属未聚在一起,表明这些属的区别较大,不是一个单系群;(5)黑蝗亚科和秃蝗亚科关系较近,且与本研究中其他几个亚科的亲缘关系相对较远。研究结果表明COⅡ基因在解决斑腿蝗科的亚科以下属种间的系统发育关系时是一个有效的分子标记。

A total of 22 species （representing 10 subfamilies and 16 genera） and an outgroup species, Filchnerella sunanensis, were sampled in this study. A 585 bp sequence of COⅡ gene was amplified using PCR, and then sequenced directly through cycling sequencing method. Several statistical approaches were used to test the phylogenetic signal in the DNA sequence data sets and three partition data sets, which were defined based on different codon positions. Phylogenetic analyses by the Neighbor Joining （N J）, maximum parsimony （MP）, maximum likelihood （ML） and Bayesian inference （BI） were employed to reconstruct the phylogeny. The results indicated that the COⅡ gene sequences of 22 data sets contained strong phylogenetic signal. It can species were highly A ＋ T biased. All of the different be found from the consensus tree that： （1） the relationships among Calliptaminae, Cyrtacanthacridinae, Eyprepocnemisinae and Catantopinae are close. （2） The relationship between Caryandinae and Oxyinae is also close. It is so reasonable to include the subfamily Caryandinae into the subfamily Oxyinae, with Spathosterninae as sister group. （3） Melanoplinae should merge with Podisminae into one subfamily. （4） The relationships of species and genera within Coptacrinae, as well as its relationships with other subfamilies were not resolved. （5） The relationship between Melanoplinae and Podisminae is close, and both are distant to other subfamilies here studied. The results prove that COⅡ gene is a useful marker to infer phylogenetic relationships among species and genera within a subfamily.