title: The genome and occlusion bodies of marine Penaeus monodon nudivirus (PmNV, also known as MBV and PemoNPV) suggest that it should be assigned to a new nudivirus genus that is distinct from the terrestrial nudiviruses.
abstract: BACKGROUND
  Penaeus monodon nudivirus (PmNV) is the causative agent of spherical baculovirosis in shrimp (Penaeus monodon). This disease causes significant mortalities at the larval stage and early postlarval (PL) stage and may suppress growth and reduce survival and production in aquaculture. The nomenclature and classification status of PmNV has been changed several times due to morphological observation and phylogenetic analysis of its partial genome sequence. In this study, we therefore completed the genome sequence and constructed phylogenetic trees to clarify PmNV's taxonomic position. To better understand the characteristics of the occlusion bodies formed by this marine occluded virus, we also compared the chemical properties of the polyhedrin produced by PmNV and the baculovirus AcMNPV (Autographa californica nucleopolyhedrovirus).
  
  
  RESULTS
  We used next generation sequencing and traditional PCR methods to obtain the complete PmNV genome sequence of 119,638 bp encoding 115 putative ORFs. Phylogenetic tree analysis showed that several PmNV genes and sequences clustered with the non-occluded nudiviruses and not with the baculoviruses. We also investigated the characteristics of PmNV polyhedrin, which is a functionally important protein and the major component of the viral OBs (occlusion bodies). We found that both recombinant PmNV polyhedrin and wild-type PmNV OBs were sensitive to acid conditions, but unlike the baculoviral OBs, they were not susceptible to alkali treatment.
  
  
  CONCLUSIONS
  From the viral genome features and phylogenetic analysis we conclude that PmNV is not a baculovirus, and that it should be assigned to the proposed Nudiviridae family with the other nudiviruses, but into a distinct new genus (Gammanudivirus).
authors: Yi-Ting
authors: YT
authors: Yang
authors: Der-Yen
authors: DY
authors: Lee
authors: Yongjie
authors: Y
authors: Wang
authors: Jer-Ming
authors: JM
authors: Hu
authors: Wen-Hsiung
authors: WH
authors: Li
authors: Jiann-Horng
authors: JH
authors: Leu
authors: Geen-Dong
authors: GD
authors: Chang
authors: Huei-Mien
authors: HM
authors: Ke
authors: Shin-Ting
authors: ST
authors: Kang
authors: Shih-Shun
authors: SS
authors: Lin
authors: Institute of Bioinformatics and Biosignal Transduction, College of Bioscience and Biotechnology, National Cheng Kung University, Tainan, Taiwan. ghkou@ntu.edu.tw.
authors: Guang-Hsiung
authors: GH
authors: Kou
authors: Chu-Fang
authors: CF
authors: Lo
mesh_terms: D000818:Animals; D059001:Aquatic Organisms / Q000821:virology*; D016367:Baculoviridae / Q000145:classification / Q000235:genetics* / Q000378:metabolism / Q000502:physiology*; D012321:DNA-Directed RNA Polymerases / Q000235:genetics / Q000378:metabolism; D016679:Genome, Viral / Q000235:genetics; D023281:Genomics; D059014:High-Throughput Nucleotide Sequencing; D008969:Molecular Sequence Data; D009055:Mouth / Q000821:virology; D016366:Open Reading Frames / Q000235:genetics; D033561:Penaeidae / Q000821:virology*; D010802:Phylogeny; D021122:Protein Subunits / Q000235:genetics / Q000378:metabolism; D012091:Repetitive Sequences, Nucleic Acid / Q000235:genetics; D012689:Sequence Homology, Nucleic Acid; D013045:Species Specificity; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism; D019065:Virus Assembly / Q000235:genetics
chemical_list: D021122:Protein Subunits; D014764:Viral Proteins; D012321:DNA-Directed RNA Polymerases