Three Mitochondrial Genomes of Chrysochroinae (Coleoptera, Buprestidae) and Phylogenetic Analyses

Three mitochondrial genomes of Chrysochroinae (Buprestidae) were sequenced and analyzed. The mitogenomes of the genera Catoxantha and Nipponobuprestis are first reportedand Chrysochroa opulenta is a first record for China. The complete mitogenomes of Catoxantha luodiana, Nipponobuprestis guangxiensis and Chrysochroa opulenta exhibit striking similarities in their lengths and composition. Specifically, their lengths are 15,594 bp, 15,775 bp and 15,587 bp, respectively. Each of these genomes encodes 37 typical mitochondrial genes. The overwhelming majority of protein-coding genes (PCGs) have the typical ATN (ATT, ATA, ATG or ATC) as the start codon and terminate with TAR (TAA or TAG) as the stop codon or an incomplete stop codon T-. Among the three mitogenomes, Leu2, Ser2 and Phe were the most frequently encoded amino acids. In the PCGs, the Ka/Ks ratio of cox1 is the lowest, whereas atp6 has the highest value. This suggests that cox1 can be used as a molecular barcode for species delimitation and phylogeny in Chrysochroinae. The phylogenetic results showed that C. luodiana and two Chrysochroa species formed a clade. Based on the topology of the phylogenetic tree, the genus Catoxantha should be reassigned as a subgenus of Chrysochroa.