title: Isolation and characterization of Solenopsis invicta virus 3, a new positive-strand RNA virus infecting the red imported fire ant, Solenopsis invicta.
abstract: We report the discovery of a new virus from the red imported fire ant, Solenopsis invicta. Solenopsis invicta virus 3 (SINV-3) represents the third virus discovered from this ant species using the metagenomics approach. The single (positive)-strand RNA, monopartite, bicistronic genome of SINV-3 was sequenced in entirety (GenBank accession number FJ528584), comprised of 10,386 nucleotides, and polyadenylated at the 3' terminus. This genome size was confirmed by Northern analysis. The genome revealed 2 large open reading frames (ORFs) in the sense orientation with an untranslated region (UTR) at each end and between the two ORFs. The 5' proximal ORF (ORF 1) encoded a predicted protein of 299.1 kDa (2580 amino acids). The 3' proximal ORF (ORF 2) encoded a predicted protein of 73.2 kDa (651 amino acids). RNA-dependent RNA polymerase (RdRp), helicase, and protease domains were recognized in ORF 1. SDS-PAGE separation of purified SINV-3 particles yielded 2 bands (ostensibly capsid proteins) with a combined molecular mass of 77.3 kDa which was similar to the mass predicted by ORF 2 (73.2 kDa). Phylogenetic analysis of the conserved amino acid sequences containing domains I to VIII of the RdRp from dicistroviruses, iflaviruses, plant small RNA viruses, picornaviruses, and 4 unassigned positive-strand RNA viruses revealed a trichotomous phenogram with SINV-3 and Kelp fly virus comprising a unique cluster. Electron microscopic examination of negatively stained samples of SINV-3 revealed isometric particles with apparent projections and a diameter of 27.3+/-1.3 nm. SINV-3 was successfully transmitted to uninfected workers by feeding. The minus (replicative) strand of SINV-3 was detected in worker ants indicating replication of the virus. The possibility of using SINV-3 as a microbial control agent for fire ants is discussed.
authors.affiliation: Center for Medical, Agricultural and Veterinary Entomology, USDA-ARS, 1600 SW 23rd Drive, Gainesville, FL 32608, USA. Steven.Valles@ars.usda.gov
authors.forename: Steven M
authors.initials: SM
authors.lastname: Valles
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Hashimoto
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001000:Ants / Q000235:genetics / Q000821:virology*; D016679:Genome, Viral; D007304:Insect Viruses / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D008854:Microscopy, Electron; D008969:Molecular Sequence Data; D010802:Phylogeny; D012328:RNA Viruses / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000648:ultrastructure; D012333:RNA, Messenger / Q000235:genetics; D012367:RNA, Viral / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D016415:Sequence Alignment; D014764:Viral Proteins / Q000737:chemistry
chemical_list: D012333:RNA, Messenger; D012367:RNA, Viral; D014764:Viral Proteins