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

Authors: OEBAYO, JAMES - Kwara State University; VALERO, CARMEN - University Of Illinois; SUN, WEILIN - Michigan State University; Coates, Brad; OMOLOYO, ADEBAYO - University Of Ibadan; PITTENDRIGH, BARRY - Michigan State University

Submitted to: AGRI GENE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/27/2016
Publication Date: 10/1/2016
Citation: Oebayo, J.O., Valero, C.M., Sun, W., Coates, B.S., Omoloyo, A.A., Pittendrigh, B.R. 2016. Comparison of full mitochondrial genomes for the rice weevil, Sitophilus oryzae and the maize weevil, Sitophilus zeamais (Coleoptera: Curculionidae). AGRI GENE. 2:29-37.

Interpretive Summary: Insect pests of stored grains cause significant damage to materials for food and biofuel industries, and are major contributors to human hunger and malnutrition in developing countries. Effective measures to control these insects are lacking, as are methods to differentiate closely related species that oftentimes are pests of different stored grain products. An ARS scientist and university collaborators sequenced the mitochondrial genome of two economically important weevils, the corn grain weevil and the rice grain weevil. Variation between these two genome sequences were identified, which are useful for molecular differentiation. These data will be used to help define species within the grain weevil pest complex.

Technical Abstract: 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 (2,818 bp) and S. zeamais (2,832 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 remains paraphyletic. The mitogenomes of these two Sitophilus species provide insight into short-term evolutionary relationships among curulionid beetles, and provide resources for the potential deciphering of more broad systematic questions in the Order Coleoptera.