The complete mitochondrial genome of Epicauta chinensis (Coleoptera: Meloidae) and phylogenetic analysis among Coleopteran insects.

ABSTRACT

The blister beetle is an important resource insect due to its defensive substance cantharidin, which was widely used in pharmacology and plant protection. We determined the complete mitochondrial genome of Epicauta chinensis Laporte (Coleoptera Tenebrionoidae Meloidae). The circular genome is 15,717 bp long, encoding 13 protein-coding genes (PCGs), two ribosomal RNAs and 22 tRNAs and containing a A+T-rich region with gene arrangement identical to other Coleopteran species. Twelve PCGs start with typical ATN codon, while ATP8 gene initiate with GTT for first report in Insecta. All PCGs terminate with conventional stop codon TAA or TAG. All tRNAs in E. chinensis are predicted to fold into typical cloverleaf secondary structure, except tRNA-Ser(AGN), in which the dihydrouracil arm (DHU arm) could not form stable stem-loop structure. The secondary structure of lrRNA and srRNA comprises 48 helices and 32 helices respectively. The 1101 bp A+T-rich region contains a 15 bp poly-T stretch and microsatellite-like repeats rather than large tandem repetitive sequences. Phylogenetic analysis, based on 13 PCGs of 45 Coleopteran species, show that E. chinensis grouped with Tenebrionidae species. It also support the topology of (((Chrysomelidae+Curculionoidea)+(Cucujoidea+Cleroidea))+Tenebrionoidea) within Cucujiformia.