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Submitted to: Gene
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 3/13/2014 Publication Date: 6/1/2014 Citation: Coates, B.S. 2014. Assembly and annotation of full mitochondrial genomes for the corn rootworm species, Diabrotica virgifera virgifera and D. barberi (Insecta: Coleoptera: Chrysomelidae), using Next Generation Sequence data. Gene. 542(2):190-197. Interpretive Summary: The western corn rootworm (WCR) and northern corn rootworm (NCR) are serious insect pests that feed on corn crops in the United States and cause and estimated > $3 billion in economic loss to producers each year due to reduced yield and increased input costs. WCR and NCR have evolved resistance to corn soybean rotations, but by different genetic mechanisms. Additionally, both species show resistance to chemical insecticide applications which cause difficulties for population suppression and crop yield improvement. The full mitochondrial genome was sequenced for WCR and NCR using next generation sequencing technologies which expedite DNA sequence acquisition and for subsequent assembly. An ARS Scientist developed methods for rapid sequencing and assembly of mitochondrial genomes, and used the data to estimate the degree of relatedness between WCR and NCR. This information will be useful for government, university and private sector scientists who wish to streamline DNA sequencing protocols, and will be important for estimating the likelihood that these two corn rootworm species may co-evolve resistance to producer practices. Technical Abstract: Complete mitochondrial genomes for two corn rootworm species, Diabrotica v. virgifera (16,747 bp) and D. barberi (16,632; Insecta: Coleoptera: Chrysomelidae), were assembled from Illumina HiSeq2000 read data. Annotation indicated that the order and orientation of 13 protein coding genes (PCGs), and 22 tRNA and 2 rRNA sequences were in typical of insect mitochondrial genomes. Non-standard nad4 and cox3 stop codons were composed of single T nucleotides and likely completed by adenylation, and atypical TTT start codons was predicted for both D. v. virgifera and D. barbari nad1 genes. The D. v. virgifera and D. barberi haplotypes showed 819 variable nucleotide positions within PCG regions (7.36% divergence), which suggest speciation may have occurred ~3.68 million years ago assuming a linear rate of short-term substitution. Phylogenetic analyses of coleopteran MtD genome show clustering based on Family level, and may have the capacity to resolve the evolutionary history within this order of insects. |
