The complete mitochondrial genome of the cockroach Eupolyphaga sinensis (Blattaria: Polyphagidae) and the phylogenetic relationships within the Dictyoptera.

We present the complete mitochondrial DNA sequence of Eupolyphaga sinensis. This closed circular molecule is 15553 bp long and consists of 37 genes that encode for 13 inner membrane proteins, 2 ribosomal RNAs and 22 transfer RNAs. The genome shares the gene order and orientation with previously known Blattaria mitochondrial genomes. All tRNAs could be folded into the typical cloverleaf secondary structure, but the tRNASer (AGN) appears to be missing the DHU arm. The A + T-rich region is 857 bp long and longer than other cockroaches. Based on the concatenated amino acid sequences of all protein coding genes of E. sinensis in conjunction with those 23 other arthropod sequences, we reconstruct the phylogenetic tree. Phylogenetic analyses shows that Blataria (including Isoptera) and the Mantodea are sister groups. Furthermore the relationship of the three basal clades of winged insects are different from the three previous hypotheses ((Ephemeroptera + Odonata) +Neoptera, Ephemeroptera + (Odonata + Neoptera), Odonata + (Ephemeroptera +Neoptera)). The Ephemeroptera (Parafronurus youi) clusters with the Plecoptera (Pteronarcys princes).