Mitochondrial genomes of four satyrine butterflies and phylogenetic relationships of the family Nymphalidae (Lepidoptera: Papilionoidea).

The complete mitochondrial genomes (mitogenomes) of four Satyrini butterflies are newly determined and comparatively analyzed. These mitogenomes are all circular, double-stranded molecules, with the lengths of 15,194 bp (Minois dryas), 15,232 bp (Ypthima motschulskyi), 15,217 bp (Neope muirheadi) and 15,279 bp (Mycalesis francisca). Gene content and arrangement of newly sequenced mitogenomes are highly conserved and are typical of Lepidoptera. Interestingly, in M. francisca, a 48-bp insertion of macrosatellite (TA)24 is present at the trnE and trnF junction, which is rare in Lepidoptera. Among 13 protein-coding genes (PCGs) of reported Satyrinae mitogenomes, atp8 is a comparatively fast-evolving gene, and most PCGs of the four species sequenced show significant codon usage bias. Phylogenetic analyses based on the mitogenomes placed the four species sequenced in this study in Satyrini, confirming the result of morphological phylogeny. Moreover, phylogenetic analyses of the family Nymphalidae based on an expanded sampling and gene data from the GenBank and the present study show that several subtribe-level relationships in the speciose Satyrini are well supported as that previously defined by multiple-locus investigations. However, the subfamily-level relationships are not fully consistent across inference methods, and this needs further investigation based on mitogenome sequences of increased taxon sampling.