Genotypic and phenotypic diversity of a baculovirus population within an individual insect host

Cory, Jenny S.; Green, Bernadette M.; Paul, Robin K.; Hunter-Fujita, Frances R.

doi:10.1016/j.jip.2005.03.008

Cited by 121 publications

(136 citation statements)

References 45 publications

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“…OBs were isolated from the cadavers as described by Cory, Green, Paul, and Hunter-Fujita (2005) with slight modifications. The cadavers were macerated in 500 μl milli-Q water using 0.1% SDS and filtered through three layers of muslin-cloth to clear large insect debris.…”

Section: Virus Amplification and Purificationmentioning

confidence: 99%

Biological and genetic characterization of a Pakistani isolate of Spodoptera litura nucleopolyhedrovirus

Ali¹,

Werf

Vlak

2017

Biocontrol Science and Technology

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Spodoptera litura is an emerging insect pest in a wide range of crops worldwide. The insect is difficult to control because of resistance development to synthetic insecticides and emerging resistance to Bacillus thuringiensis toxins. Therefore, there is a need to develop biological control agents, preferably from an indigenous source to avoid risks associated with the importation of exotic natural antagonists. A Pakistani isolate of S. litura nucleopolyhedrovirus (SpltNPV, Baculoviridae), SpltNPV-Pak-BNG, was obtained from the field and characterized biologically and genetically, and compared to a SpltNPV reference isolate, SpltNPV-G1, thought to be of Chinese origin. The dose-mortality response (LD 50 ) of SpltNPVPak-BNG was not significantly different from that of the reference isolate SpltNPV-G1, but the time-to-death (LT 50 ) was significantly shorter for SpltNPV-Pak-BNG than for SpltNPV-G1. DNA restriction enzyme profiling indicated that SpltNPV-Pak-BNG and SpltNPV-G1 are different viruses. Sequence analysis of 'ORF24', specific for SpltNPV (and S. littoralis NPV as ORF21), and the conserved baculovirus core genes polyhedrin, DNApol, pif-2 and lef-8 confirmed that this was indeed the case and that SpltNPV-Pak-BNG is a genuine SpltNPV variant, whereas the SpltNPV-G1 isolate we used is, in fact, a SpliNPV variant, renamed to SpliNPV-G1. The newly isolated SpltNPV-Pak-BNG has the potential for development as a biocontrol agent of S. litura in Pakistan.ARTICLE HISTORY

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Section: Virus Amplification and Purificationmentioning

confidence: 99%

Biological and genetic characterization of a Pakistani isolate of Spodoptera litura nucleopolyhedrovirus

Ali¹,

Werf

Vlak

2017

Biocontrol Science and Technology

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“…This diversity has been demonstrated by the characterization of different geographical isolates of the same virus (6,7) and also within single isolates, which frequently comprise a mixture of genotypes (8,9,10). In wild-type populations, genetic diversity seems to be an important aspect of virus survival under field conditions to allow adaptation to varied environmental conditions (11,12).…”

mentioning

confidence: 99%

A Chrysodeixis chalcites Single-Nucleocapsid Nucleopolyhedrovirus Population from the Canary Islands Is Genotypically Structured To Maximize Survival

Bernal

Simón

Williams

et al. 2013

Appl Environ Microbiol

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A Chrysodeixis chalcites single-nucleocapsid nucleopolyhedrovirus wild-type isolate from the Canary Islands, Spain, named ChchSNPV-TF1 (ChchTF1-wt), appears to have great potential as the basis for a biological insecticide for control of the pest. An improved understanding of the genotypic structure of this wild-type strain population should facilitate the selection of genotypes for inclusion in a bioinsecticidal product. Eight genetically distinct genotypes were cloned in vitro: ChchTF1-A to ChchTF1-H. Quantitative real-time PCR (qPCR) analysis confirmed that ChchTF1-A accounted for 36% of the genotypes in the wild-type population. In bioassays, ChchTF1-wt occlusion bodies (OBs) were significantly more pathogenic than any of the component single-genotype OBs, indicating that genotype interactions were likely responsible for the pathogenicity phenotype of wild-type OBs. However, the wild-type population was slower killing and produced higher OB yields than any of the single genotypes alone. These results strongly suggested that the ChchTF1-wt population is structured to maximize its transmission efficiency. Experimental OB mixtures and cooccluded genotype mixtures containing the most abundant and the rarest genotypes, at frequencies similar to those at which they were isolated, revealed a mutualistic interaction that restored the pathogenicity of OBs. In OB and cooccluded mixtures containing only the most abundant genotypes, ChchTF1-ABC, OB pathogenicity was even greater than that of wild-type OBs. The ChchTF1-ABC cooccluded mixture killed larvae 33 h faster than the wild-type population and remained genotypically and biologically stable throughout five successive passages in vivo. In conclusion, the ChchTF1-ABC mixture shows great potential as the active ingredient of a bioinsecticide to control C. chalcites in the Canary Islands.

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“…Coinfection by multiple genotypes is a common characteristic of many host-parasite systems, especially insect viruses (5,6,14,(19)(20)(21). When multiple virus particles infect individual host cells, deletion mutants can arise that have lost genes that are essential for transmission or replication (35).…”

mentioning

confidence: 99%

Mixtures of Complete andpif1- andpif2-Deficient Genotypes Are Required for Increased Potency of an Insect Nucleopolyhedrovirus

Clavijo

Williams

Simón

et al. 2009

J Virol

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The insecticidal potency of a nucleopolyhedrovirus population (SfNIC) that infects Spodoptera frugiperda (Lepidoptera) is greater than the potency of any of the component genotypes alone. Occlusion bodies (OBs) produced in mixed infections comprising the complete genotype and a deletion genotype are as pathogenic as the natural population of genotypes from the field. To test whether this increased potency was due to the deletion or to some other characteristic of the deletion variant genome, we used the SfNIC-B genome to construct a recombinant virus (SfNIC-B⌬16K) with the same 16.4-kb deletion as that observed in SfNIC-C and another recombinant (SfNIC-B⌬pifs) with a deletion encompassing two adjacent genes (pif1 and pif2) that are essential for transmission per os. Mixtures comprising SfNIC-B and SfNIC-B⌬16K in OB ratios that varied between 10:90 and 90:10 were injected into insects, and the progeny OBs were fed to larvae in an insecticidal potency assay. A densitometric analysis of PCR products indicated that SfNIC-B was generally more abundant than expected in mixtures based on the proportions of OBs used to produce the inocula. Mixtures derived from OB ratios of 10, 25, or 50% of SfNIC-B⌬16K and the corresponding SfNIC-B proportions showed a significant increase in potency compared to SfNIC-B alone. The results of potency assays with mixtures comprising various proportions of SfNIC-B plus SfNIC-B⌬pifs were almost identical to the results observed with SfNIC-B⌬16K, indicating that deletion of the pif gene region was responsible for the increased potency observed in mixtures of SfNIC-B and each deletion recombinant virus. Subsequently, mixtures produced from OB ratios involving 10 or 90% of SfNIC-B⌬16K with the corresponding proportions of SfNIC-B were subjected to four rounds of per os transmission in larvae. The composition of each experimental mixture rapidly converged to a common equilibrium with a genotypic composition of ϳ85% SfNIC-B plus ϳ15% SfNIC-B⌬16K. Nearly identical results were observed in peroral-passage experiments involving mixtures of SfNIC-B plus SfNICB⌬pifs. We conclude that (i) the deletion of the pif1 and pif2 region is necessary and sufficient to explain the increased potency observed in mixtures of complete and deletion genotypes and (ii) viral populations with decreased ratios of pif1-and pif2-deficient genotypes in the virus population increase the potency of genotypic mixtures and are likely to positively influence the transmission of this pathogen.

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Genotypic and phenotypic diversity of a baculovirus population within an individual insect host

Cited by 121 publications

References 45 publications

Biological and genetic characterization of a Pakistani isolate of Spodoptera litura nucleopolyhedrovirus

Biological and genetic characterization of a Pakistani isolate of Spodoptera litura nucleopolyhedrovirus

A Chrysodeixis chalcites Single-Nucleocapsid Nucleopolyhedrovirus Population from the Canary Islands Is Genotypically Structured To Maximize Survival

Mixtures of Complete andpif1- andpif2-Deficient Genotypes Are Required for Increased Potency of an Insect Nucleopolyhedrovirus

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