Full genome sequence of a novel iflavirus from the aster leafhopper Macrosteles fascifrons.

The aster leafhopper Macrosteles fascifrons is a common insect pest that feeds on rice and other plants and may serve as a vector to transmit various viruses. Here, we discovered a novel virus from M. fascifrons using metagenomic sequencing. We obtained its complete genome sequence by contig assembly and rapid amplification of cDNA ends, and verified the genome sequence by Sanger sequencing of overlapping segments. Based on homology search and phylogenetic analysis, the new virus belongs to the family Iflaviridae and it is tentatively named "Macrosteles fascifrons iflavirus 1" (MfIV1). Excluding the poly(A) tail, the MfIV1 genome is 10,581 nucleotides in length and it is predicted to encode a polyprotein of 3119 amino acids long, which is likely further processed to several polypeptides with conserved domains, including two rhinovirus like (rhv-like) capsid domains, a cricket paralysis virus (CRPV) capsid domain, a helicase domain, and an RNA-dependent RNA polymerase (RdRp) domain. BLAST searches show that the highest amino acid sequence identity between the capsid proteins of MfIV1 and those of other reported iflaviruses is 60.22%, indicating that MfIV1 is a new member in the family Iflaviridae.

Full genome sequence of a novel iflavirus from the leafhopper Recilia dorsalis.

The leafhopper Recilia dorsalis (family Cicadellidae, tribe Deltocephalini) is a common pest of rice and a transmitter of various viruses. Here, we discovered a novel virus in an R. dorsalis sample and determined its complete genome sequence by metagenomic sequencing and rapid amplification of cDNA ends. Based on a homology search and phylogenetic analysis, we show that the new virus belongs to the genus Iflavirus, family Iflaviridae, and we have tentatively named it "Recilia dorsalis iflavirus 1" (RdIV1). Excluding the polyA tail, the RdIV1 genome is 10,986 nucleotides in length and is predicted to encode a 3,195-amino-acid-long polyprotein that possesses the typical domains of iflaviruses: two rhinovirus-like (rhv-like) capsid domains, a cricket paralysis virus-like (CRPV-like) capsid domain, a helicase domain, a protease domain, and an RNA-dependent RNA polymerase (RdRp) domain. BLAST searches showed that the RdIV1 genome has the highest amino sequence identity (73.8%) in the coat protein region to Euscelidius variegatus virus 1 (EVV-1), a member of to the genus Iflavirus, indicating that RdIV1 can be classified as a new iflavirus.