Genome Sequencing and Analysis of Catopsilia pomona nucleopolyhedrovirus: A Distinct Species in Group I Alphabaculovirus.

Jun Wang,Zheng Zhu,Fei Deng,Lei Zhang,Dianhai Hou,Basil Arif,Zhihong Hu,Hualin Wang,Manli Wang,Zheng Kou

doi:10.1371/journal.pone.0155134

Abstract

The genome sequence of Catopsilia pomona nucleopolyhedrovirus (CapoNPV) was determined by the Roche 454 sequencing system. The genome consisted of 128,058 bp and had an overall G+C content of 40%. There were 130 hypothetical open reading frames (ORFs) potentially encoding proteins of more than 50 amino acids and covering 92% of the genome. Among all the hypothetical ORFs, 37 baculovirus core genes, 23 lepidopteran baculovirus conserved genes and 10 genes conserved in Group I alphabaculoviruses were identified. In addition, the genome included regions of 8 typical baculoviral homologous repeat sequences (hrs). Phylogenic analysis showed that CapoNPV was in a distinct branch of clade “a” in Group I alphabaculoviruses. Gene parity plot analysis and overall similarity of ORFs indicated that CapoNPV is more closely related to the Group I alphabaculoviruses than to other baculoviruses. Interesting, CapoNPV lacks the genes encoding the fibroblast growth factor (fgf) and ac30, which are conserved in most lepidopteran and Group I baculoviruses, respectively. Sequence analysis of the F-like protein of CapoNPV showed that some amino acids were inserted into the fusion peptide region and the pre-transmembrane region of the protein. All these unique features imply that CapoNPV represents a member of a new baculovirus species.

Highlights

Members of the family Baculoviridae are rod-shaped, insect-specific viruses with doublestranded large circular DNA genomes of 80–180 kb [1, 2]
Lepidopteran baculoviruses synthesize two progeny phenotypes, the budded virus (BV) and occlusion-derived virus (ODV). Virus particles of the latter phenotype are embedded into occlusion bodies (OBs) [3], which offer some protection against environmental inactivating conditions such as UV light, heat and desiccation
The genome was covered 350 times by 123,698 reads. It consists of 128,058 bp in length and contains 130 predicted open reading frames (ORFs) with a G+C content of 40% (S2 Table)

Summary

Introduction

Members of the family Baculoviridae are rod-shaped, insect-specific viruses with doublestranded large circular DNA genomes of 80–180 kb [1, 2]. Despite the diversity in gene content of baculovirus genomes, 37 have been identified as core genes present in all sequenced baculoviral genomes and play very important roles in the viral replication cycle [10]. There are 23 genes conserved in all sequenced lepidopteran baculoviruses (NPVs and GVs) and 11 are specific to Group I [10,11,12,13]. 78 baculoviruses have been fully sequenced, including 19 Group I alphabaculoviruses, 35 Group II alphabaculoviruses, 20 betabaculoviruses, 3 gammabaculoviruses and 1 deltabaculovirus (http://www.ncbi.nlm.nih.gov/genomes/GenomesGroup.cgi?taxid=10442, and S1 Table).

Results

Conclusion