Genetic structural variation in mitochondrial genomes of four species of Gomphidae and their phylogenetic implications

Abstract

The Gomphids are the most diverse and important group in the (sub)tropics. Currently, research on Gomphids is mainly focused on fieldwork and morphological classification, however, the molecular-based study is still insufficient. Here, complete mitogenomes of Nihonogomphus semanticus (15,368 bp), Nihonogomphus lieftincki (15,342 bp), Asiagomphus septimus (15,334 bp), and Davidius fruhstorferi (15,682 bp) were obtained by high-throughput sequencing. Of the 37 genes conserved in order and orientation, 9 protein-coding genes (PCGs) and 14 tRNA genes were encoded by heavy strand, while the rest were encoded by light strand. The secondary structures of the protein encoded by 13 PCGs showed a general trend of proportion: α helix > random coil > extended strand > β turn. The trnS1 gene lacked a dihydrouridine arm and was thus reduced to a loop. The 3D structures of the protein encoded by 13 PCGs showed moderate to high levels of consistency among species. Phylogenetic analysis showed that Gomphids were well-supported monophyletic group, both BI and ML tree showed clear phylogenetic relationships in known Gomphidae: ((((D. lunatus + D. fruhstorferi) + A. septimus) + ((N. semanticus + N. lieftincki) + Ophiogomphus cecilia)) + Ictinogomphus sp MT 2014). Our study provides insight into the gene or their protein structure features of the family Gomphidae mitogenomes and lays the foundation for further phylogenetic studies.