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. 2019 Jul 12;9(1):10086.
doi: 10.1038/s41598-019-46008-y.

The first clawed lobster virus Homarus gammarus nudivirus (HgNV n. sp.) expands the diversity of the Nudiviridae

Corey C Holt  1   2   3   4 , Michelle Stone  5 , David Bass  5   6   7 , Kelly S Bateman  5 , Ronny van Aerle  5   6 , Carly L Daniels  8 , Mark van der Giezen  9   6 , Stuart H Ross  5 , Chantelle Hooper  5 , Grant D Stentiford  10   11
Affiliations

The first clawed lobster virus Homarus gammarus nudivirus (HgNV n. sp.) expands the diversity of the Nudiviridae

Corey C Holt et al. Sci Rep. .

Abstract

Viral diseases of crustaceans are increasingly recognised as challenges to shellfish farms and fisheries. Here we describe the first naturally-occurring virus reported in any clawed lobster species. Hypertrophied nuclei with emarginated chromatin, characteristic histopathological lesions of DNA virus infection, were observed within the hepatopancreatic epithelial cells of juvenile European lobsters (Homarus gammarus). Transmission electron microscopy revealed infection with a bacilliform virus containing a rod shaped nucleocapsid enveloped in an elliptical membrane. Assembly of PCR-free shotgun metagenomic sequencing produced a circular genome of 107,063 bp containing 97 open reading frames, the majority of which share sequence similarity with a virus infecting the black tiger shrimp: Penaeus monodon nudivirus (PmNV). Multiple phylogenetic analyses confirm the new virus to be a novel member of the Nudiviridae: Homarus gammarus nudivirus (HgNV). Evidence of occlusion body formation, characteristic of PmNV and its closest relatives, was not observed, questioning the horizontal transmission strategy of HgNV outside of the host. We discuss the potential impacts of HgNV on juvenile lobster growth and mortality and present HgNV-specific primers to serve as a diagnostic tool for monitoring the virus in wild and farmed lobster stocks.

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Conflict of interest statement

The authors declare no competing interests.

Figures

Figure 1
Figure 1
Homarus gammarus nudivirus (HgNV) infection within the hepatopancreas. (A) Section through the hepatopancreas, haemal sinus (HS) surrounds the tubules, cross section of the tubules shows a clear lumen (*). Infected nuclei within the epithelial cells of the tubules are enlarged, with emarginated chromatin and possess an eosinophilic inclusion body (white arrows). Infected cells (black arrow) may be sloughed into the lumen of the tubules. H&E Stain. Scale bar = 50 µm. (B) Infections can be seen within multiple epithelial cells, infected nuclei appearing larger than uninfected nuclei. Margination of the chromatin can form septa leading to the appearance of discrete intranuclear compartmentalisation (arrow). H&E Stain. Scale bar = 20 µm. (C,D) HgNV-specific DNA polymerase probe hybridised to infected nuclei (arrows) within epithelial cells of the hepatopancreas. In-situ hybridisation. Scale bar = 100 µm, 50 µm respectively. (E) Nucleus from a HgNV infected cell containing rod-shaped virions. Virions accumulate at the periphery of the nuclear membrane (arrow), TEM. Scale bar = 500 nm. (F) Longitudinal (white arrow) and transverse sections (black arrow) of HgNV virions within the nucleus. Virions possess an electron dense nucleocapsid surrounded by a trilaminar membrane (envelope). The rod shaped nucleocapsid appears to bend within the envelope forming a “u” or “v” shape in some cases (line arrows). TEM. Scale bar = 500 nm.
Figure 2
Figure 2
Prevalence of intranuclear inclusions in sea-based and hatchery lobsters over 104 weeks. Proportion of surviving lobsters displaying histopathological signs of viral infection. Green triangles: hatchery-based animals. Blue circles: sea-based animals. Sample size indicated at each point.
Figure 3
Figure 3
HgNV circular genome plot. Visual representation of HgNV layout scaled to the complete 107 063 bp contiguous sequence. Outermost track shows GC content (%) across complete sequence. Dark blue track displays gene predictions localised to the forward strand, whereas light blue displays those on the reverse. The innermost track depicts direct repeat regions. Links highlight genes involved in similar functions; yellow - DNA replication and repair, red - nucleotide metabolism, green – RNA transcription, pale blue – per os infectivity, pink – packaging and assembly, and grey – apoptosis inhibition.
Figure 4
Figure 4
HgNV homologs to conserved nudivirus sequences. Colours as in Fig. 3. *Fused to a single gene. **Multiple copy number. Shaded cells of second column indicate ‘core nudivirus genes’ shared with the Baculoviridae. + Reported present.
Figure 5
Figure 5
Single and multigene phylogenies of known nudiviruses. Maximum Likelihood analyses of nudivirus phylogeny, including whispovirus and baculovirus outgroups. Node labels indicate bootstrap support (%). (A) – Single gene phylogeny of DNA polymerase. (B) – Single gene phylogeny of DNA helicase. (C) – Multigene phylogeny of late expression factors (lef-4, lef-5, lef-8, lef-9 and p47). (D) – Multigene phylogeny of per os infectivity genes (pif-0, pif-1, pif-2, pif-3, pif-4, pif-5 and pif-6). DiNV – Drosophila innubila nudivirus, KNV – Kallithea virus (D. melanogaster), ENV – Esparto virus (D. melanogaster), TNV – Tomelloso virus (D. melanogaster), OrNV – Oryctes rhinoceros nudivirus, NleNV – Nilaparvata lugens endogenous nudivirus, GbNV – Gryllus bimaculatus, HzNV-1 – Heliothis zea nudivirus 1, HzNV-2 – Heliocoverpa (syn. Heliothis) zea nudivirus 2, HgNV – Homarus gammarus nudivirus, PmNV – Penaeus monodon nudivirus, ToNV - Tipula oleracea nudivirus, NeleNPV – Neodipirion lecontei nucleopolyhedrovirus, NeseNPV – Neodipirion sertifer nucleopolyhedrovirus, AcMNPV – Autographa californica multiple nucleopolyhedrovirus, AgseGV – Agrotis segetum granulovirus, and WSSV – white spot syndrome virus. Coloured clade groupings refer to proposed genera: yellow – Alphanudiviruses, pink – Betanudiviruses, green – Gammanudiviruses, blue – Deltanudiviruses, red – Baculoviruses, cream – Whispovirus.
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References

    1. Stentiford GD, et al. Disease will limit future food supply from the global crustacean fishery and aquaculture sectors. J. Invertebr. Pathol. 2012;110:141–157. doi: 10.1016/j.jip.2012.03.013. - DOI - PubMed
    1. Suttle CA. Viruses in the sea. Nature. 2005;437:356. doi: 10.1038/nature04160. - DOI - PubMed
    1. Shields JD. A new pathogenic virus in the Caribbean spiny lobster Panulirus argus from the Florida Keys. Dis. Aquat. Organ. 2004;59:109–118. doi: 10.3354/dao059109. - DOI - PubMed
    1. Shields JD. Diseases of spiny lobsters: A review. J. Invertebr. Pathol. 2011;106:79–91. doi: 10.1016/j.jip.2010.09.015. - DOI - PubMed
    1. Behringer DC, Butler IM, Shields J. Avoidance of disease by social lobsters. Nature. 2006;441(441):421. doi: 10.1038/441421a. - DOI - PubMed

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