Genome sequence and molecular characterization of Homalodisca coagulata virus-1, a novel virus discovered in the glassy-winged sharpshooter (Hemiptera: Cicadellidae)

Abstract

The complete nucleotide sequence of a novel single-stranded RNA virus infecting the glassy-winged sharpshooter, Homalodisca coagulata, has been determined. In silico analysis of H. coagulata virus-1 (HoCV-1) revealed a 9321-nt polyadenylated genome encoding two large open reading frames (ORF1 and ORF2) separated by a 182-nt intergenic region (IGR). The deduced amino acid sequence of the 5'-proximal ORF (ORF1, nt 420-5807) exhibited conserved core motifs characteristic of the helicases, cysteine proteases, and RNA-dependent RNA polymerases of other insect-infecting picorna-like viruses. A structural model created using Mfold exposed a series of stem loop (SL) structures immediately preceding the second ORF which are analogous to an internal ribosome entry site (IRES), suggesting that ORF2 begins with a noncognate GCA triplet rather than the canonical AUG. This 3' ORF2 (5990-8740) showed significant similarity to the structural proteins of members of the family Dicistroviridae, particularly those belonging to the genus Cripavirus. Evidence demonstrating relatedness of these viruses regarding genome organization, amino acid sequence similarity, and putative replication strategy substantiate inclusion of HoCV-1 into this taxonomic position.

Insect cell culture and applications to research and pest management

“…In Hemiptera, there have been advances in leafhopper cell culture development (Kamita et al 2005), which supports the replication of ssRNA dicistroviruses (Boyapalle et al 2006; (2004) 1 lepidopteran Several of these viruses replicate in cell lines derived from different insect orders, as indicated in the third column. This table represents a subset of non-NPVs able to replicate in insect cell lines Hunnicutt et al 2006;Hunter et al 2006) and the development of the first psyllid cell cultures, Diaphorina citri (Marutani-Hert et al 2009), which has yielded a new dsRNA reovirus, as well as is the first such culture within hemipterans to be used to culture endosymbiotic bacteria. Lastly, polydnaviruses produce persistent infections with their DNA being incorporated into the host cell genome (Gundersen-Rindal and Dougherty 2000;Gundersen-Rindal and Lynn 2003).…”

A Baculovirus-Expressed Dicistrovirus That Is Infectious to Aphids

“…Thus, our goal was to construct an infectious cDNA clone of the RhPV genome to gain insight into the control of gene expression, replication, assembly, and structure of a replicating dicistrovirus. The genomes of several dicistroviruses have been sequenced (22,25,41,44). Dicistroviruses harbor two very different, well-characterized internal ribosome entry sites (IRESs) that facilitate the translation of the two open reading frames ORFs (36,40).…”

Biological Control of Parasites

“…The leafhopper-infecting virus, Homalodisca coagulate virus-1 (HoCV-1, Dicistroviridae), has been shown to increase leafhopper mortality [90,91]. The virus occurs in nature and spreads most readily at high population densities through contact among infected individuals, contact with virus-contaminated surfaces and/or as an aerosol in leafhopper excreta.…”