Discovery and characterization of a novel alphavirus-like RNA virus from the red firebug Pyrrhocoris apterus L. (Heteroptera)

Abstract

Recent studies have shown that insects harbor numerous viruses of various taxa and that viral infections are often latent without noticeable symptoms. The red firebug Pyrrhocoris apterus, a true flightless bug from the family Pyrrhocoridae, is widely used for physiological studies on insect metabolism, endocrinology, and digestion. While exploring the transcriptome of P. apterus salivary glands, a nearly complete genomic sequence of a novel RNA virus was reconstructed. The virus, provisionally named Pyrrhocoris apterus virus 1 (PaV1), possesses eight potential open reading frames (ORFs) encoding for an array of proteins, some of which are involved in virus replication while others ensure success of the virus in multiple ways, including evasion of the host immune response. In addition to the information obtained from sequence analyses, we documented virus transmission, virus-induced mortality, host response upon persistent PaV1 infection, virion morphology, and putative virus-induced structures in salivary gland cells in a laboratory culture of red firebug. We propose that PaV1 belongs to a novel viral species of a new, yet-to-be established family.