Nymphalidae is the largest family of butterflies with their phylogenetic relationships not adequately approached to date. The mitochondrial genomes (mitogenomes) of 11 new nymphalid species were reported and a comparative mitogenomic analysis was conducted together with other 22 available nymphalid mitogenomes. A phylogenetic analysis of the 33 species from all 13 currently recognized nymphalid subfamilies was done based on the mitogenomic data set with three Lycaenidae species as the outgroups. The mitogenome comparison showed that the eleven new mitogenomes were similar with those of other butterflies in gene content and order. The reconstructed phylogenetic trees reveal that the nymphalids are made up of five major clades (the nymphaline, heliconiine, satyrine, danaine and libytheine clades), with sister relationship between subfamilies Cyrestinae and Biblidinae, and most likely between subfamilies Morphinae and Satyrinae. This whole mitogenome-based phylogeny is generally congruent with those of former studies based on nuclear-gene and mitogenomic analyses, but differs considerably from the result of morphological cladistic analysis, such as the basal position of Libytheinae in morpho-phylogeny is not confirmed in molecular studies. However, we found that the mitogenomic phylogeny established herein is compatible with selected morphological characters (including developmental and adult morpho-characters).

The complete mitochondrial genome sequences of the two butterfly speciesEuploea mulciber(Lepidoptera: Nymphalidae: Danainae) andLibythea celtis(Lepidoptera: Nymphalidae: Libytheinae) were determined in this study, comprising 15,166 bp and 15,164 bp, respectively. The orientation and the gene order of the two mitogenomes are identical to those of most of the other lepidopteran species. All protein-coding genes ofEuploea mulciberandLibythea celtismitogenomes start with a typical ATN codon with the exception of COI gene which uses CGA as its initial codon. All tRNA genes possess the typical cloverleaf secondary structure except for tRNASer(AGN), which has a simple loop with the absence of the DHU stem. There are short microsatellite-like repeat regions, but no conspicuous macrorepeats scattered throughout the A + T-rich regions. Phylogenetic analysis among the available butterfly species suggests thatLibythea celtis(Libytheinae) is closely related toCalinaga davidis(Calinaginae), indicating that the subfamily Libytheinae may not represent a basal lineage of the Nymphalidae as previously suggested, and thatEuploea mulciberstands at the base of the nymphalid tree as a sister to all other nymphalids.

The softshell turtles (Trionychidae) are one of the most widely distributed reptile groups in the world, and fossils have been found on all continents except Antarctica. The phylogenetic relationships among members of this group have been previously studied; however, disagreements regarding its taxonomy, its phylogeography and divergence times are still poorly understood as well. Here, we present a comprehensive mitogenomic study of softshell turtles. We sequenced the complete mitochondrial genomes of 10 softshell turtles, in addition to the GenBank sequence of Dogania subplana, Lissemys punctata, Trionyx triunguis, which cover all extant genera within Trionychidae except for Cyclanorbis and Cycloderma. These data were combined with other mitogenomes of turtles for phylogenetic analyses. Divergence time calibration and ancestral reconstruction were calculated using BEAST and RASP software, respectively. Our phylogenetic analyses indicate that Trionychidae is the sister taxon of Carettochelyidae, and support the monophyly of Trionychinae and Cyclanorbinae, which is consistent with morphological data and molecular analysis. Our phylogenetic analyses have established a sister taxon relationship between the Asian Rafetus and the Asian Palea + Pelodiscus + Dogania + Nilssonia + Amyda, whereas a previous study grouped the Asian Rafetus with the American Apalone. The results of divergence time estimates and area ancestral reconstruction show that extant Trionychidae originated in Asia at around 108 million years ago (MA), and radiations mainly occurred during two warm periods, namely Late Cretaceous-Early Eocene and Oligocene. By combining the estimated divergence time and the reconstructed ancestral area of softshell turtles, we determined that the dispersal of softshell turtles out of Asia may have taken three routes. Furthermore, the times of dispersal seem to be in agreement with the time of the India-Asia collision and opening of the Bering Strait, which provide evidence for the accuracy of our estimation of divergence time. Overall, the mitogenomes of this group were used to explore the origin and dispersal route of Trionychidae and have provided new insights on the evolution of this group.

Abstract:The complete mitochondrial genome of Apatura ilia (GenBank accession no. JF437925) was determined as a circular DNA molecule of 15 242 bp, with common genes of 13 putative proteins, 2 rRNAs, and 22 tRNAs and of the same gene arrangement as in other sequenced lepidopterans. All protein-coding genes had the typical start codon ATN, except for the COI's using CGA as its start codon as previously demonstrated in other lepidopteran species. The comparison of the nucleotide sequences of the A. ilia mitogenome with ten other Nymphalidae species showed nearly identical gene orientation and arrangement, with only a few alterations in non-coding fragments. The nucleotide composition and codon frequency all fell into the range estimated for the order Lepidoptera. The A. ilia mitochondrial genome had the canonical set of 22 tRNA genes folded in the typical cloverleaf structure, with an unique exception of tRNA Ser (AGN). The mitochondrial genes from A. ilia were overlapped in a total of 33 bp at 9 locations, as well as interleaved with a total of 155 bp intergenic spacers, spread over 12 regions with the size ranging from 1 to 49 bp. Furthermore, the spacer between ND6 and Cyt b harbored a microsatellite-like repeat (TA) 23 not found in other completely sequenced nymphalid genomes. The 403 bp AT-rich region harbored two conserved motifs (ATAGA, ATTTA), a 21 bp polyT stretch, a 10 bp poly-A region, along with two microsatellite-like repeats ( (TA) 10 and (TA) 7 ), as detected in other nymphalid butterflies.