Characterization of Two Complete Mitochondrial Genomes of Ledrinae (Hemiptera: Cicadellidae) and Phylogenetic Analysis

SIMPLE SUMMARY: Ledrinae is a small subfamily with many unique characteristics and comprises 5 tribes with 39 genera including approximately 300 species. The monophyly of Ledrinae and the phylogenetic relationships among cicadellid subfamilies remain controversial. To provide further insight into the taxonomic status and phylogenetic status of Ledrinae, two additional complete mitochondrial genomes of Ledrinae species (Tituria sagittata and Petalocephala chlorophana) are newly sequenced and comparatively analyzed. The results showed the sequenced genes of Ledrinae retain the putative ancestral order for insects. In this study, phylogenetic analyses based on expanded sampling and gene data from GenBank indicated that Ledrinae appeared as monophyletic with maximum bootstrap support values and maximum Bayesian posterior probabilities. Bayesian inference and maximum likelihood analysis of concatenated alignments of three datasets produced a well-resolved framework of Cicadellidae and valuable data toward future study in this subfamily. ABSTRACT: Mitochondrial genomes are widely used for investigations into phylogeny, phylogeography, and population genetics. More than 70 mitogenomes have been sequenced for the diverse hemipteran superfamily Membracoidea, but only one partial and two complete mtgenomes mitochondrial genomes have been sequenced for the included subfamily Ledrinae. Here, the complete mitochondrial genomes (mitogenomes) of two additional Ledrinae species are newly sequenced and comparatively analyzed. Results show both mitogenomes are circular, double-stranded molecules, with lengths of 14,927 bp (Tituria sagittata) and 14,918 bp (Petalocephala chlorophana). The gene order of these two newly sequenced Ledrinae is highly conserved and typical of members of Membracoidea. Similar tandem repeats in the control region were discovered in Ledrinae. Among 13 protein-coding genes (PCGs) of reported Ledrinae mitogenomes, analyses of the sliding window, nucleotide diversity, and nonsynonymous substitution (Ka)/synonymous substitution (Ks) indicate atp8 is a comparatively fast-evolving gene, while cox1 is the slowest. Phylogenetic relationships were also reconstructed for the superfamily Membracoidea based on expanded sampling and gene data from GenBank. This study shows that all subfamilies (sensu lato) are recovered as monophyletic. In agreement with previous studies, these results indicate that leafhoppers (Cicadellidae) are paraphyletic with respect to the two recognized families of treehoppers (Aetalionidae and Membracidae). Relationships within Ledrinae were recovered as (Ledra + (Petalocephala + Tituria)).