The Complete Mitochondrial Genome of Agrilus zanthoxylumi Li, 1989 (Buprestidae: Agrilinae): Genome Characterization and Phylogenetic Implications

Few mitogenomes sequences are available for Agrilus species in the family Buprestidae. To explore the mitochondrial genome features and their phylogenetic relationships, the complete mitogenome of the trunk borer jewel beetle, Agrilus zanthoxylumi, Li, 1989 (花椒窄吉丁) was sequenced and annotated. The complete 16,320 bp genome encodes 37 mitochondrial genes, including 13 protein-coding genes (PCGs), 22 transfer RNA (tRNA) genes, 2 ribosomal RNA genes, and a 1526-bp-long AT-rich region. Most of the PCGs, except ND1 which uses TTG had typical ATN start codons, and terminated with TAA/TAG or a single T residue. In addition, UUA (Leu2), UCU (Ser2), CGA (Arg), and GGA (Gly) were the four most frequently used codons. All tRNAs were folded into a secondary cloverleaf structure, except for tRNASer, which lacks the DHU arm. The analysis of the nonsynonymous and synonymous substitution rates of PCGs showed that a strong purifying and negative selection exists in those buprestid beetles. Phylogenetic analyses within the subfamily Agrilinae were performed using concatenation methods based on multiple matrices from mitochondrial genes. The phylogenetic results indicated that A. zanthoxylumi is clustered with other species of Agrilus. All phylogenetic trees supported the monophyly of Agrilinae and Trachini, but the tribal relationship in Agrilinae remains ambiguous.