Aphis glycines virus 1, a new bicistronic virus with two functional internal ribosome entry sites, is related to a group of unclassified viruses in the Picornavirales

A novel picorna-like virus, provisionally named Aphis glycines virus 1 (ApGIV1) was discovered by high-throughput sequencing of soybean total RNAs and detected in suction trap-collected Aphis glycines. The ApGIV1 genome contains two large ORFs organized similar to those of dicipiviruses in the Picornaviridae where ORFs 1 and 2 encode structural and nonstructural proteins, respectively. Both ORFs are preceded by internal ribosome entry site (IRES) elements. The 5' IRES was more active in dual luciferase activity assays than the IRES in the intergenic region. The ApGIV1 genome was predicted to encode a serine protease instead of a cysteine protease and showed very low as sequence identities to recognized members of the Picornavirales. In phylogenetic analyses based on capsid protein and RNA-dependent RNA polymerase sequences, ApGIV1 consistently clustered with a group of unclassified bicistronic picorna-like viruses discovered from arthropods and plants that may represent a novel family in the order Picornavirales.