The Complete Mitochondrial Genome of Four Hylicinae (Hemiptera: Cicadellidae): Structural Features and Phylogenetic Implications.

Abstract

Simple SummaryHylicinae, containing 43 described species in 13 genera of two tribes, is one of the most morphologically unique subfamilies of Cicadellidae. Phylogenetic studies on this subfamily were mainly based on morphological characters or several gene fragments and just involved single or two taxa. No mitochondrial genome was reported in Hylicinae before. Therefore, we sequenced and analyzed four complete mtgenomes of Hylicinae (Nacolus tuberculatus, Hylica paradoxa, Balala fujiana, and Kalasha nativa) for the first time to reveal mtgenome characterizations and reconstruct phylogenetic relationships of this group. The comparative analyses showed the mtgenome characterizations of Hylicinae are similar to members of Membracoidea. In phylogenetic results, Hylicinae was recovered as a monophyletic group in Cicadellidae and formed to the sister group of Coelidiinae + Iassinae. These results provide the comprehensive framework and worthy information toward the future researches of this subfamily.To reveal mtgenome characterizations and reconstruct phylogenetic relationships of Hylicinae, the complete mtgenomes of four hylicine species, including Nacolus tuberculatus, Hylica paradoxa, Balala fujiana, and Kalasha nativa, were sequenced and comparatively analyzed for the first time. We also carried out the richest (11) subfamily sampling of Cicadellidae to date, and reconstructed phylogenetic relationships of Membracoidea among 61 species based on three datasets using maximum likelihood and Bayesian inference analyses. All new sequenced mtgenomes are molecules ranging from 14,918 to 16,221 bp in length and are double stranded, circular in shape. The gene composition and arrangement of these mtgenomes are consistent with members of Membracoidea. Among 13 protein-coding genes, most show typical ATN start codons and TAR (TAA/TAG) or an incomplete stop codon T–, and several genes start by TTG/GTG. Results of the analysis for sliding window, nucleotide diversity, and nonsynonymous substitution/synonymous substitution indicate cox1 is a comparatively slower-evolving gene while atp8 is the fastest gene. In line with previous researches, phylogenetic results indicate that treehopper families are paraphyletic with respect to family Cicadellidae and also support the monophyly of all involved subfamilies including Hylicinae. Relationships among the four hylicine genera were recovered as (Hylica + (Nacolus + (Balala + Kalasha))).