Comparative mitochondrial genome analysis of Grammodes geometrica and other noctuid insects reveals conserved mitochondrial genome organization and phylogeny.

ABSTRACT

The mitochondrial genome (mitogenome) plays an important role in revealing molecular evolution. In this study, the complete mitogenome of Grammodes geometrica (G. geometrica) (Lepidoptera Erebidae) was sequenced and characterized. The nucleotide composition of the genome is highly A + T biased, accounting for 80.49%. Most protein-coding genes (PCGs) are initiated by ATN codons except for the cytochrome oxidase subunit 1 (cox1) gene, which was initiated by CGA. The order and orientation of genes with the order trnM-trnI-trnQ-nad2 is a typical rearrangement compared with those ancestral insects in which trnM is located between trnQ and nad2. Most tRNA genes were folded into the typical cloverleaf structure except for trnS1 (AGN). The A + T-rich region contains the conserved motif "ATAGA" followed by a 19 bp poly-T stretch, which was also observed in other Noctuoidea species. In addition, we reconstructed phylogenetic trees among the nucleotide alignments of five families of Noctuoidea species except the Oenosandridae. Finally, we achieved a well-supported tree, which showed that G. geometrica belongs to the Erebidae family. Moreover, the relationships at the family-level can be displayed as follows (Notodontidae + (Erebidae + (Nolidae + (Euteliidae + Noctuidae)))).