Molecular Phylogenetic Analysis Of Some Species Of Limenitinae Based On Mitochondrial Cytb And COI Sequences

Limenitinae is one of the biggest subfamilies in Nymphalidae (Lepidoptera: Nymphalidae). There are 46 genera and 800 species all over the world. The majority of them is of medium or large size and mostly distributed in the Middle and North America, Paleoarctic and Oriental areas . The Limenitinae of China includes 118 species covering 22 genera, mostly distributed in southern areas of our country. So far, the taxonomical studies of this subfamily is mostly based on the traditional morphological characters, and in contract, their molecular systematic researches is still very limited up to now. In this study, 2 mitochondrial genes (COI and Cytb) were used as molecular markers, and the phylogenetic trees of some representative species of the butterflies this subfamily were reconstructed using phylogenetic analysis softwares, hence providing molecular evidences for their systematical and phylogenetic studies. Totally, the partial COI sequences (about 650bp) of eighteen species of Limenitinae and the Cytb sequences (about 430bp) of twenty five species of Limenitinae were amplified and sequenced. Upon this sequence data, the base composition, substitution saturation and base composition bias among these taxa have been tested, meanwhile, the phylogenetic trees were reconstructed with neighbor-joining (NJ), maximum parsimony (MP) and Bayesian inference (BI) methods. After analysing and discussing these results, we draw the conclusions as follows:1. It is found that there are high ratio of A + T in both of Cytb and COI in these species of Limenitinae with 69.6% and 74.4%, respectively, showing a strong AT bias.2. Among the nucleotide substitutions of Cytb and COI, the transitions occur more frequently than the transversions, and also do the case of the base bias at the 3rd position of Cytb gene among these taxa.3. whether Limenitinae is classified as a separate subfamily or not, The comprehensive analyses of their morphological and this molecular studies is in congruent with the opinion that Limenitinae should be restricted to the genera and subtribes placed in the tribe Limenitidini by Harvey (1991).4. It is indicated that the involved species of this subfamily clustered into two clades: the first clade includes those of the genus Neptis, Phaedyma, Pantoporia and Lintinga; the second one includes those of the genus Parthenos, Moduza, Limenitis, Athyma, Lexias and Euthalia. The genus Limenitis is suggested to be monophyletic; and the genera Euthalia and Lexias proved to be sister to each other and form a monophyletic group. The genus Litinga appears to be more closely related to Neptini than to Limenitini. However, the phylogenetic positions of some genera, such as Phaedyma, Pantoporia and Lintinga, are not well-resolved in the present study.The present study provided the preliminary analyses about the molecular evolution characteristics and phylogenetic inference of some Limenitinae taxonomical groups, aiming at clarifying their phylogenetic relationships more clearly and constructing their systematics catergories more reasonably.