Replication and Occlusion Body Formation of Spodoptera exigua Multicapsid Nucleopolyhedrovirus in a Homologous Cell Line

A new ascovirus was isolated from Spodoptera exigua in Indonesia and was tentatively assigned as a new species, Spodoptera exigua ascovirus 5a (SeAV-5a) according to the present ICTV ascovirus naming scheme based on DNA restriction fragment length polymorphism (RFLP), hybridization, formation of occlusion body, tissue tropism and host spectrum. SeAV-5a replicated primarily in the fat body of susceptible hosts. SeAV-5a could be transmitted to S. frugiperda, Pseudoplusia includens and Trichoplusia ni, but not to Heliothis virescens. Infection with SeAV-5a arrested growth of the hosts, but prolonged their survival, which continued up to 33 days. Clusters of virions were seen inside the characteristic vesicles. Occasionally, virions were contained within vacuoles (one to five per vacuole) and some virions were embedded in occlusion bodies. The size of the SeAV-5a virion was 347×134 nm; however, aberrant long secondary viral products were also seen. The presence of occlusion body and Southern hybridization and Western immunoblot analyses suggest that SeAV-5a is more closely related to S. frugiperda ascovirus 1a (SfAV-1a) than to Trichoplusia ni ascovirus 2 (TnAV-2). Certain regions of the 182 kb genome of SeAV-5a showed hybridization to that of SfAV-1a. Two fragments in each of the SfAV-1a EcoRI and HindIII digests hybridized to the SeAV-5a genomic DNA probe. Five to eight HindIII and EcoRI fragments in SeAV-5a DNA hybridized to the SfAV-1a genomic probe.

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A new cell line from Spodoptera exigua (Lepidoptera: Noctuidae) and its differentially expressed genes

Journal of Applied Entomology ◽

10.1111/j.1439-0418.2011.01689.x ◽

2011 ◽

Vol 136 (8) ◽

pp. 632-637 ◽

Cited By ~ 8

Author(s):

A. Zhang ◽

X. Li ◽

H. Zhang ◽

H. Wang ◽

L. Miao ◽

...

Keyword(s):

Cell Line ◽

Differentially Expressed Genes ◽

Spodoptera Exigua ◽

Differentially Expressed ◽

New Cell Line ◽

Lepidoptera Noctuidae

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A cloned cell line ofSpodopteta exiguahas a highly increased susceptibility to theSpodoptera exiguanuclear polyhedrosis virus

Canadian Journal of Microbiology ◽

10.1139/m95-154 ◽

1995 ◽

Vol 41 (12) ◽

pp. 1111-1116 ◽

Cited By ~ 31

Author(s):

Koyu Hara ◽

Masako Funakoshi ◽

Takeshi Kawarabata

Keyword(s):

Cell Line ◽

Spodoptera Exigua ◽

Nuclear Polyhedrosis Virus ◽

Plaque Assay ◽

Virus Production ◽

Parental Cell ◽

Parental Cell Line ◽

Parent Cell ◽

Polyhedrosis Virus ◽

Nuclear Polyhedrosis

A cloned cell line designated Se301, derived from a continuous Se3FH cell line of the beet army worm Spodoptera exigua, showed 10 times greater sensitivity when tested with the plaque assay to a S. exigua nuclear polyhedrosis virus (SeNPV) as compared with the parent cell line. Nearly 100% of Se301 cells were infected with the plaque purified isolate SeNPV-I1 or the wild isolate SeNPV-IW. Plaques were first detected 3–4 days in the Se301 cell line, which was 1–2 days faster than the Se3FH cell line. The size of plaques formed in the Se301 cell line was markedly larger than that of the parental cell line. At 12 h post infection, the production of the extracellular viruses (ECVs) in the Se301 cell line infected with either SeNPV-I1 or SeNPV-IW was 20–40 times greater than that in the Se3FH cell line. In contrast, Se301 cells infected with SeNPV-I1 or SeNPV-IW produced polyhedral inclusion bodies (PIBs) at lower levels compared with Se3FH cells. The isolate SeNPV-I1 consistently produced more ECVs and PIBs in both the Se301 and Se3FH cell lines than the isolate SeNPV-IW.Key words: Spodoptera exigua, nuclear polyhedrosis virus, cloned cell line, increased virus sensitivity, virus production.

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A Conserved Phenylalanine Residue of Autographa Californica Multiple Nucleopolyhedrovirus AC75 Protein Is Required for Occlusion Body Formation

Frontiers in Microbiology ◽

10.3389/fmicb.2021.663506 ◽

2021 ◽

Vol 12 ◽

Author(s):

Xingang Chen ◽

Jian Yang ◽

Xiaoqin Yang ◽

Chengfeng Lei ◽

Xiulian Sun ◽

...

Keyword(s):

Virus Production ◽

Autographa Californica ◽

Occlusion Body ◽

Body Formation ◽

Viral Propagation ◽

Multiple Nucleopolyhedrovirus ◽

Infected Cells ◽

Budded Virus ◽

Conserved Gene ◽

Autographa Californica Multiple Nucleopolyhedrovirus

Autographa californica multiple nucleopolyhedrovirus (AcMNPV) orf75 (ac75) is a highly conserved gene that is essential for AcMNPV propagation. However, the key domains or residues of the AC75 protein that play a role in viral propagation have not been identified. In this study, sequence alignment revealed that residues Phe-54 and Gln-81 of AC75 were highly conserved among alphabaculoviruses and betabaculoviurses. Thus, Phe-54 and Gln-81 AC75 mutation bacmids were constructed. We found that Gln-81 was not required for viral propagation, whereas mutating Phe-54 reduced budded virus production by 10-fold and impaired occlusion body formation when compared with that of the wild-type AcMNPV. Electron microscopy observations showed that the Phe-54 mutation affected polyhedrin assembly and also occlusion-derived virus embedding, whereas western blot analysis revealed that mutating Phe-54 reduced the amount of AC75 but did not affect the localization of AC75 in infected cells. A protein stability assay showed that the Phe-54 mutation affected AC75 stability. Taken together, Phe-54 was identified as an important residue of AC75, and ac75 is a pivotal gene in budding virus production and occlusion body formation.

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