Genome sequence of a novel positive sense, single-stranded RNA virus isolated from western corn rootworm, Diabrotica virgifera virgifera LeConte

Authors: LIU, SIJUN - Iowa State University; CHEN, YUTING - Iowa State University; Sappington, Thomas; BONNING, BRYONY - Iowa State University

Submitted to: Genome Announcements
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/28/2017
Publication Date: 5/18/2017
Citation: Liu, S., Chen, Y., Sappington, T.W., Bonning, B.C. 2017. Genome sequence of a novel positive sense, single-stranded RNA virus isolated from western corn rootworm, Diabrotica virgifera virgifera LeConte. Genome Announcements. 5(20):e00366-17. doi: 10.1128/genomeA.00366-17.

Interpretive Summary: Western corn rootworm (WCR), Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae), is a significant pest on maize in the United States, causing severe economic loss, and has invaded much of western Europe. Given the resistance of this species to many current control methods, efforts are underway to devise novel, virus-based management approaches for this pest. Thus, we are investigating the viral pathogens of WCR. WCR adults were collected from cornfields in the U.S. (Iowa, Arizona, Colorado, Pennsylvania), Europe (Hungary, Croatia, Austria), and from laboratory colonies that originated from collections in the U.S. RNA was extracted and sequenced to determine if virus sequences were present. The genome sequence of a novel small RNA virus was identified from the RNA, with weak similarity to a dicistrovirus found in a mammal. Although the genome of DvvV3 is dicistrovirus-like, the protein sequences encoded are divergent from these and other insect viruses, suggestive of a new type of single-stranded RNA virus. Small RNA viruses of insects have potential for insect pest management. This information will be used by university, government, and industry scientists in their search for, and development of, possible biocontrol agents for rootworms and other beetle pests of crops.

Technical Abstract: The genome sequence of a novel small RNA virus was assembled from the transcriptome of the western corn rootworm, Diabrotica virgifera virgifera, and has tentatively been named Diabrotica virgifera virgifera virus 3 (DvvV3). The assembled genome has 13,182 nucleotides with a 3’ polyadenylated tail. Two open reading frames are predicted to encode polyproteins of 2,838 and 1,073 amino acids. Although the genome of DvvV3 is dicistrovirus-like, the protein sequences encoded are divergent from these and other insect viruses, suggestive of a new type of positive-sense ssRNA virus. Sequences of DvvV3 were detected in field collected samples from the U.S. and Europe, and laboratory cultures of D. v. virgifera originating from U.S. collections, suggesting that this virus is widely distributed within WCR populations in the United States.