Complete genome analysis of a novel chuvirus from a southern green stink bug (Nezara viridula)

A novel chuvirus from a southern green stink bug (Nezara viridula) was identified by RNA sequencing in this study and was tentatively named "Ningbo southern green stink bug chuvirus 1" (NBSGSBV-1). The complete genome sequence of NBSGSBV-1 consists of 11,375 nucleotides, and the genome was found to be circular by 'around-the-genome' reverse transcription polymerase chain reaction (RT-PCR) and Sanger sequencing. Three open reading frames (ORFs) were predicted in the NBSGSBV-1 genome, encoding a large polymerase protein (L protein), a glycoprotein (G protein), and a nucleocapsid protein (N protein). A phylogenetic tree was constructed based on all of the currently available RNA-dependent RNA polymerase amino acid sequences of viruses of the family Chuviridae, and NBSGSBV-1 was found to cluster together with Sanya chuvirus 2 and Hubei odonate virus 11, indicating that NBSGSBV-1 might belong to the genus Odonatavirus. Five conserved sites were identified in the L proteins of NBSGSBV-1 and other chuviruses. The abundance and characteristics of the NBSGSBV-1-derived small interfering RNAs suggested that NBSGSBV-1 actively replicates in the host insect. To the best of our knowledge, this is the first report of a chuvirus identified in a member of the insect family Pentatomidae. The discovery and characterization of NBSGSBV-1 will help us to understand the diversity of chuviruses in insects.