Journal Article

The Complete Genome Sequence of a Second Distinct Betabaculovirus from the True Armyworm, Mythimna unipuncta

Bauchan, Gary R., Rowley, Daniel L., Erlandson, Martin A., Harrison, Robert L., Theilmann, David A., Rohrmann, George F., Mowery, Joseph

2017

Overview

The betabaculovirus originally called Pseudaletia (Mythimna) sp. granulovirus #8 (MyspGV#8) was examined by electron microscopy, host barcoding PCR, and determination of the nucleotide sequence of its genome. Scanning and transmission electron microscopy revealed that the occlusion bodies of MyspGV#8 possessed the characteristic size range and morphology of betabaculovirus granules. Barcoding PCR using cytochrome oxidase I primers with DNA from the MyspGV#8 collection sample confirmed that it had been isolated from the true armyworm, Mythimna unipuncta (Lepidoptera: Noctuidae) and therefore was renamed MyunGV#8. The MyunGV#8 genome was found to be 144,673 bp in size with a nucleotide distribution of 49.9% G+C, which was significantly smaller and more GC-rich than the genome of Pseudaletia unipuncta granulovirus H (PsunGV-H), another M. unipuncta betabaculovirus. A phylogeny based on concatenated baculovirus core gene amino acid sequence alignments placed MyunGV#8 in clade a of genus Betabaculovirus. Kimura-2-parameter nucleotide distances suggested that MyunGV#8 represents a virus species different and distinct from other species of Betabaculovirus. Among the 153 ORFs annotated in the MyunGV#8 genome, four ORFs appeared to have been obtained from or donated to the alphabaculovirus lineage represented by Leucania separata nucleopolyhedrovirus AH1 (LeseNPV-AH1) during co-infection of Mythimna sp. larvae. A set of 33 ORFs was identified that appears only in other clade a betabaculovirus isolates. This clade a-specific set includes an ORF that encodes a polypeptide sequence containing a CIDE_N domain, which is found in caspase-activated DNAse/DNA fragmentation factor (CAD/DFF) proteins. CAD/DFF proteins are involved in digesting DNA during apoptosis.

• Publisher: Public Library of Science,Public Library of Science (PLoS)
• Subject: Agriculture / Amino acid sequence / Amino acids / Analysis / Animals / Apoptosis / Armyworms / Baculovirus / Base Sequence / Biology and Life Sciences / Biopesticides / Caspase / Cytochrome / Cytochrome oxidase I / Deoxyribonuclease / Deoxyribonucleic acid / DNA / DNA barcoding / DNA Barcoding, Taxonomic / DNA fragmentation / DNA, Viral - genetics / Electron microscopy / Gene expression / Genetic aspects / Genome, Viral / Genomes / Genomics / Granulovirus - genetics / Granulovirus - isolation & purification / Granulovirus - ultrastructure / Identification and classification / Laboratories / Larvae / Lepidoptera - virology / Microscopy / Microscopy, Electron, Scanning / Microscopy, Electron, Transmission / Mythimna unipuncta / Nucleotide sequence / Occlusion / Occlusion bodies / Open Reading Frames / Phylogeny / Physical characteristics / Plant phylogeny / Polymerase chain reaction / Primers / Proteins / Pseudaletia / Pseudaletia unipuncta / R&D / Research & development / Research and Analysis Methods / RNA polymerase / Studies / Transmission electron microscopy / Viral Proteins - genetics / Virology / Viruses