A Novel Betabaculovirus Isolated from the Monocot Pest Mocis latipes (Lepidoptera: Noctuidae) and the Evolution of Multiple-Copy Genes

Abstract

In this report, we described the genome of a novel baculovirus isolated from the monocot insect pest Mocis latipes, the striped grass looper. The genome has 134,272 bp in length with a G + C content of 38.3%. Based on the concatenated sequence of the 38 baculovirus core genes, we found that the virus is a betabaculovirus closely related to the noctuid-infecting betabaculoviruses including Pseudaletia unipuncta granulovirus (PsunGV), Trichoplusia ni granulovirus (TnGV), Helicoverpa armigera granulovirus (HearGV), and Xestia c-nigrum granulovirus (XecnGV). The virus may constitute a new Betabaculovirus species tentatively named Mocis latipes granulovirus (MolaGV). After gene content analysis, five open reading frames (ORFs) were found to be unique to MolaGV and several auxiliary genes were found including iap-3, iap-5, bro-a, bro-b, and three enhancins. The virus genome lacked both chitinase and cathepsin. We then looked at the evolutionary history of the enhancin gene and found that betabaculovirus acquired this gene from an alphabaculovirus followed by several duplication events. Gene duplication also happened to an endonuclease-like gene. Genomic and gene content analyses revealed both a strict collinearity and gene expansion into the genome of the MolaGV-related species. We also characterized the granulin gene using a recombinant Autographa californica multiple nucleopolyhedrovirus (AcMNPV) and found that occlusion bodies were produced into the nucleus of infected cells and presented a polyhedral shape and no occluded virions within. Overall, betabaculovirus genome sequencing is of importance to the field as few genomes are publicly accessible. Mocis latipes is a secondary pest of maize, rice, and wheat crops in Brazil. Certainly, both the discovery and description of novel baculoviruses may lead to development of greener and safer pesticides in order to counteract and effectively control crop damage-causing insect populations

Gene copy number variations at the within-host population level modulate gene expression in a multipartite virus

“…Related studies on viruses have focused on monopartite large double-stranded DNA (dsDNA) viruses such as phage T4 ( Wu and Black 1995 ), baculoviruses ( Ardisson-Araújo et al. 2018 ), herpesviruses ( Arias et al.…”

Sequencing, Analysis and Organization of the Complete Genome of a Novel Baculovirus Calliteara abietis Nucleopolyhedrovirus (CaabNPV)

“…Most of baculovirus hrs contain repeated AT-rich sequences [ 38 ]. The hrs are characterized by comprising a series of tandem repeats, which include an imperfect palindromic core, interspersed at different locations in the genome [ 16 ].…”

Genomic analysis of a cypovirus isolated from the eucalyptus brown looper, Thyrinteina arnobia (Stoll, 1782) (Lepidoptera: Geometridae)

“…The S1 and S10 presented slightly less variation than it was expected for their sizes and most of the SNVs did not change the protein sequence (data not shown). The most conserved segment among the isolates was the S10 (polh gene) since single non-synonymous mutation has the potential to drastically change OB formation and impairs the ability to occlude virions as observed for baculoviruses (Coulibaly et al, 2007;Ardisson-Araújo et al, 2018). On the other hand, the S5 segment presented more SNVs than that expected by its size.…”