Comparative analysis of seven mitochondrial genomes of Phymatostetha (Hemiptera: Cercopidae) and phylogenetic implications.

In this study, we present seven mitochondrial genomes (mitogenomes) of Phymatostetha. Each mitogenome contains the entire set of 37 genes, which arranged in the same order as the putative ancestral pattern of insects. The nucleotide composition of Phymatostetha mitogenomes is biased toward A/T, with rRNAs and PCG12 (i.e. the first and second codon positions of PCGs) exhibit the highest and lowest A + T content, respectively. Relative synonymous codon usage of PCGs also show that degenerate codons are biased to use more A/T than G/C. All tRNAs exhibit typical clover-leaf structure, with the exception of trnS1. Additionally, unpaired nucleotides are detected in trnS1 anticodon stem and trnR acceptor stem. Phylogenetic relationships, based on the dataset of 13 PCGs, 22tRNAs, and two rRNAs, are analyzed using both the Bayesian and maximum likelihood methods. Our results clearly revealed the systematic status of Phymatostetha species and robustly supported the monophyly of this genus, in which Phymatostetha semele is sister to other Phymatostetha species. It was demonstrated that mitogenome was an effective molecular marker to adequately resolve phylogeny at low taxonomic levels.