Penaeus vannamei singly enveloped nuclear polyhedrosis virus (PvSNPV) (also known as Baculovirus Penaei (BP)) is the first viral pathogen of penaeid shrimp described in 1974. Although PvSNPV was discovered more than 45 years ago, the complete genome of BP is elucidated in this study for the first time. Until few years ago, BP was listed in the World Organization for Animal Health (Paris, France) list of crustaceans diseases. Development of management strategies enabled to reduce the negative impact of the virus in recent years, but it still remains prevalent in the hatchery
We detected the virus in a quarantine stock of P. vannamei by light microscopy of fecal samples and by PCR screening of broodstock. Subsequently, next generation sequencing (NGS) was deployed to determine the complete genome sequence of PvSNPV. The PvSNPV genome is a circular, double-stranded DNA molecule of 119,883 bp in length encoding 100 open reading frames (ORFs). The deduced amino acid sequences from 25 ORFs were homologous to 28 core proteins from all identified nudiviruses. Phylogenetic analyses based on deduced amino acid sequences of the core genes and orthologous genes revealed that PvSNPV clusters with Penaeus monodon nudivirus (PmNV). Therefore, we propose to rename BP/ PvSNPV as Penaeus vannamei nudivirus (PvNV) and re-assign the virus to the family Nudiviridae instead of Baculoviridae.
Figure 1. Genome organization of Baculovirus Penaei (BP), also called Penaeus vannamei singly enveloped nuclear polyhedrosis virus (PvSNPV).
Availability of the BP genome sequence will be useful in studying host-virus interactions at a molecular level and developing strategies to mitigate the negative impact in the captive breeding program to develop Specific Pathogen Free (SPF) lines of shrimp.