First Complete Mitochondrial Genome of Melyridae(Coleoptera, Cleroidea): Genome Description and Phylogenetic Implications

SIMPLE SUMMARY: Melyridae, in a broad sense including Dasytinae and Malachiinae, is the largest family of Cleroidea distributed worldwide. However, the former two subfamilies are always treated as independent families by the European coleopterists. Opposite results have been produced by the two latest molecular phylogenetic works, so the development of reliable markers for reconstructing the phylogenetic relationships between the above taxa is of great importance. Here, we present the annotated complete mitogenome of Cordylepherus sp., which is the first complete mitogenome in Melyridae. The mitogenome of Cordylepherus sp. presents the typical organization of an insect mitochondrion. Comparisons of the newly generated mitogenome of Cordylepherus sp. to all available mitochondrial genomes of other Melyridae revealed no significant differences among them in terms of the length of each protein-coding gene, AT content of different genome regions, amino acid composition and relative synonymous codon usage. Phylogenetic analyses based on 13 protein-coding genes of mitogenomes show that the monophyly of Melyridae sensu lato is not supported, and Malachiinae and Dasytinae are suggested to be independent families, which are sister groups of Prionoceridae and Cleridae, respectively. Large-scale analyses with denser locus and taxon sampling are needed to confirm the present results. ABSTRACT: To explore the characteristics of the mitogenome of Melyridae and reveal phylogenetic relationships, the mitogenome of Cordylepherus sp. was sequenced and annotated. This is the first time a complete mitochondrial genome has been generated in this family. Consistent with previous observations of Cleroidea species, the mitogenome of Cordylepherus sp. is highly conserved in gene size, organization and codon usage, and secondary structures of tRNAs. All protein-coding genes (PCGs) initiate with the standard start codon ATN, except ND1, which starts with TTG, and terminate with the complete stop codons of TAA and TAG, or incomplete forms, TA- and T-. Most tRNAs have the typical clover-leaf structure, except trnS1 (Ser, AGN), whose dihydrouridine (DHU) arm is reduced. In the A+T-rich region, three types of tandem repeat sequence units are found, including a 115 bp sequence tandemly repeated twice, a 16 bp sequence tandemly repeated three times with a partial third repeat and a 10 bp sequence tandemly repeated seven times. Phylogenetic analyses based on 13 protein-coding genes by both Bayesian inference (BI) and maximum likelihood (ML) methods suggest that Melyridae sensu lato is polyphyletic, and Dasytinae and Malchiinae are supported as independent families.