Comparison of full mitochondrial genomes for the rice weevil, Sitophilus oryzae and the maize weevil, Sitophilus zeamais (Coleoptera: Curculionidae)

- Rice and maize weevil mitochondrial genomes were assembled from next generation sequence.
- Pronounced non-coding intergenic regions with tandem repeat arrays
- Non-synonymous substitution mutations found in the two weevil mitogenomes could serve as ideal markers.
- Sequence data are good resources for evolutionary relationship among Coleoptera.

Complete mitochondrial genome sequences were assembled for the rice weevil, Sitophilus oryzae (17,602 bp) and the maize weevil, S. zeamais (18,105 bp; Coleoptera: Curculionidae: Dryophthorinae), which encode 13 protein coding genes (PCGs), 22 transfer RNAs, and 2 ribosomal RNAs that is typical among Animalia. The A + T-rich control regions of S. oryzae (2818 bp) and S. zeamais (2832 bp) are the longest described to date among curculionoidea (weevils). Additionally, non-coding intergenic regions have increased in size due to expansion of tandem repeat arrays, but is more pronounced in S. zeamais (606 bp) compared to S. oryzae (109 bp). A total of 69 and 22 substitution mutations were found among reads from S. oryzae and S. zeamais, out of which 68 and 2 were predicted in the PCGs respectively, with a majority in NADH Dehydrogenase subunit I. Phylogenetic analyses of coleopteran insects based upon full mitogenomes PCG sequence supported the existence of Curculionoidea and Tenebrionoidea as a monophyletic group, whereas the Cucujoidea and Elateroidea remain paraphyletic. The mitogenomes of these two Sitophilus species provide insight into short-term evolutionary relationships among curculionid beetles, and provide resources for the potential deciphering of more broad systematic questions in the Order Coleoptera.