scholarly journals Diverse Host Immune Responses of Different Geographical Populations of the Coconut Rhinoceros Beetle to Oryctes Rhinoceros Nudivirus (OrNV) Infection

2021 ◽  
Author(s):  
Kayvan Etebari ◽  
Maria Gharuka ◽  
Sassan Asgari ◽  
Michael J. Furlong
Keyword(s):  
Immune Responses ◽  
Pacific Islands ◽  
Biocontrol Agent ◽  
New Wave ◽  
Oryctes Rhinoceros ◽  
Host Immune Responses ◽  
Rhinoceros Beetle ◽  
Double Stranded Dna ◽  
The Pacific ◽  
Geographical Populations

Oryctes rhinoceros nudivirus (OrNV) is a double-stranded DNA (dsDNA) virus which has been used as a biocontrol agent to suppress coconut rhinoceros beetle (CRB) in the Pacific Islands. Recently a new wave of CRB incursions in Oceania is thought to be related to the presence of low-virulence isolates of OrNV or virus-tolerant haplotypes of beetles (CRB-G).

scholarly journals Transcription Profile and Genomic Variations of Oryctes Rhinoceros Nudivirus in Coconut Rhinoceros Beetles

2020 ◽  
Vol 94 (22) ◽  
Author(s):  
Kayvan Etebari ◽  
Rhys Parry ◽  
Marie Joy B. Beltran ◽  
Michael J. Furlong
Keyword(s):  
Gene Expression ◽  
Southeast Asia ◽  
Pacific Islands ◽  
Biocontrol Agent ◽  
Viral Gene Expression ◽  
Viral Gene ◽  
Content Type ◽  
Oryctes Rhinoceros ◽  
Rhinoceros Beetle ◽  
The Pacific

ABSTRACT Oryctes rhinoceros nudivirus (OrNV) is a double-stranded DNA (dsDNA) virus which has been used as a biocontrol agent to suppress the coconut rhinoceros beetle (Oryctes rhinoceros) in Southeast Asia and the Pacific Islands. A new wave of O. rhinoceros incursions in Oceania is thought to be related to the presence of low-virulence isolates of OrNV or virus-tolerant haplotypes of beetles. In this study, chronically infected beetles were collected from Philippines, Fiji, Papua New Guinea (PNG), and the Solomon Islands (SI). RNA sequencing (RNA-seq) was performed to investigate the global viral gene expression profiles and for comparative genomic analysis of structural variations. Maximum likelihood phylogenic analysis indicated that OrNV strains from the SI and Philippines are closely related, while OrNV strains from PNG and Fiji formed a distinct adjacent clade. We detected several polymorphic sites with a frequency higher than 35% in 892 positions of the viral genome. Nonsynonymous mutations were detected in several hypothetical proteins and 15 nudivirus core genes, such as gp034, lef-8, lef-4, and vp91. We found limited evidence of variation in viral gene expression among geographic populations. Only a few genes, such as gp01, gp022, and gp107, were differentially expressed among different strains. Additionally, small RNA sequencing from the SI population suggested that OrNV is targeted by the host RNA interference (RNAi) response with abundant 21-nucleotide small RNAs. Some of these genomic changes are specific to the geographic population and could be related to particular phenotypic characteristics of the strain, such as viral pathogenicity or transmissibility, and this requires further investigation. IMPORTANCE Oryctes rhinoceros nudivirus has been an effective biocontrol agent against the coconut rhinoceros beetle in Southeast Asia and the Pacific Islands for decades. The recent outbreak of these beetles in many South Pacific islands has had a significant impact on livelihoods in the region. It has been suggested that the resurgence and spread of the pest are related to the presence of low-virulence isolates of OrNV or virus-tolerant haplotypes of beetles. We examined viral genomic and transcriptional variations in chronically infected beetles from different geographical populations. A high number of polymorphic sites among several geographical strains of OrNV were identified, but potentially only a few of these variations in the genome are involved in functional changes and can potentially alter the typical function. These findings provide valuable resources for future studies to improve our understanding of the OrNV genetic variations in different geographic regions and their potential link to virus pathogenicity.

scholarly journals Genetic structure of the Coconut Rhinoceros Beetle (Oryctes rhinoceros) population and the incidence of its biocontrol agent (Oryctes rhinoceros nudivirus) in the South Pacific Islands

2020 ◽  
Author(s):  
Kayvan Etebari ◽  
James Hereward ◽  
Apenisa Sailo ◽  
Emeline M Ahoafi ◽  
Robert Tautua ◽  
...  
Keyword(s):  
Biocontrol Agent ◽  
New Caledonia ◽  
Solomon Islands ◽  
South Pacific ◽  
The Philippines ◽  
Mitochondrial Lineage ◽  
The South ◽  
Oryctes Rhinoceros ◽  
Rhinoceros Beetle ◽  
The Pacific

Incursions of the Coconut rhinoceros beetle (CRB), Oryctes rhinoceros, have been detected in several countries of the south-west Pacific in recent years, resulting in an expansion of the pest's geographic range. It has been suggested that this resurgence is related to an O. rhinoceros mitochondrial lineage (previously referred to as the CRB-G biotype) that is reported to show reduced susceptibility to the well-established classical biocontrol agent, Oryctes rhinoceros nudivirus (OrNV). We investigated O. rhinoceros population genetics and the OrNV status of adult specimens collected in the Philippines and seven different South Pacific island countries (Fiji, New Caledonia, Papua New Guinea (PNG), Samoa, Solomon Islands, Tonga, and Vanuatu). Based on the presence of single nucleotide polymorphisms (snps) in the mitochondrial Cytochrome C Oxidase subunit I (CoxI) gene, we found three major mitochondrial lineages (CRB-G, a PNG lineage (CRB-PNG) and the South Pacific lineage (CRB-S)) across the region. Haplotype diversity varied considerably between and within countries. The O. rhinoceros population in most countries was monotypic and all individuals tested belonged to a single mitochondrial lineage (Fiji, CRB-S; Tonga, CRB-S; Vanuatu, CRB-PNG; PNG (Kimbe), CRB-PNG; New Caledonia CRB-G; Philippines, CRB-G). However, in Samoa we detected CRB-S and CRB-PNG and in Solomon Islands we detected all three haplotype groups. Genotyping-by-Sequencing (GBS) methods were used to genotype 10,000 snps from 230 insects across the Pacific and showed genetic differentiation in the O. rhinoceros nuclear genome among different geographical populations. The GBS data also provided evidence for gene flow and admixture between different haplotypes in Solomon Islands. Therefore, contrary to earlier reports, CRB-G is not solely responsible for damage to the coconut palms reported since the pest was first recorded in Solomon Islands in 2015. We also PCR-screened a fragment of OrNV from 260 insects and detected an extremely high prevalence of viral infection in all three haplotypes in the region. We conclude that the haplotype groups CRB-G, CRB-S, and PNG, do not represent biotypes, subspecies, or cryptic species, but simply represent different invasions of O. rhinoceros across the Pacific. This has important implications for management, especially biological control, of Coconut rhinoceros beetle in the region.

scholarly journals First report of Ditylenchus gallaeformans in Miconia albicans from the Brazilian Cerrado, State of Goiás

2016 ◽  
Vol 37 (2) ◽  
pp. 729
Author(s):  
Rodrigo Vieira da Silva ◽  
Dalila Sêni de Jesus ◽  
Brenda Ventura de Lima e Silva ◽  
Bruno Eduardo Cardozo de Miranda ◽  
João Pedro Elias Gondim
Keyword(s):  
Pacific Islands ◽  
Biocontrol Agent ◽  
Nematode Species ◽  
Tropical Region ◽  
Invasive Weeds ◽  
Native Plant ◽  
Brazilian Cerrado ◽  
First Report ◽  
The Pacific ◽  
The Family

Miconia albicans (Melastomataceae), whose common name is canela-de-velha, is a native plant of the tropical region that is abundant in the Cerrado biome. A nematode species was found parasitizing M. albicans, causing severe deformation and gall-like structures on the infected leaves and inflorescences. Morphological, morphometric and molecular characterizations identified the nematode as Ditylenchus gallaeformans. This nematode has great potential as a biocontrol agent of plants in the family Melastomataceae, which are invasive weeds in ecosystems of the Pacific Islands. This is the first report of D. gallaeformans parasitizing M. albicans in the Cerrado of the state of Goiás.

scholarly journals Identification of a Novel Picorna-like Virus in Coconut Rhinoceros Beetles (Oryctes rhinoceros)

2020 ◽  
Author(s):  
Kayvan Etebari ◽  
Matan Shelomi ◽  
Michael J. Furlong
Keyword(s):  
Pacific Islands ◽  
Harmonia Axyridis ◽  
Pfam Domain ◽  
The Philippines ◽  
Amino Acid Sequences ◽  
Reading Frame ◽  
Oryctes Rhinoceros ◽  
Geographical Populations ◽  
South Pacific Islands ◽  
Bee Virus

AbstractA novel Picorna-like virus, tentatively named Oryctes rhinoceros Picorna-like virus 1 (OrPV1), was identified in coconut rhinoceros beetle (Oryctes rhinoceros) larvae in Taiwan. The complete genome sequence consisted of 9,665 nucleotides with a polyA tail and included one open reading frame. Conserved structural domains such as Picornavirus capsid protein, RNA helicase, Peptidase and RNA-dependent RNA polymerase (RdRp) were identified through Pfam domain searches. The genome shares approximately 28% identity with other unclassified picornavirals that infect honey bees (Darwin bee virus 2, Bundaberg bee virus 5, and Sacbrood virus) and a recently reported virus from Asian lady beetle (Harmonia axyridis virus 1). We did not detect this virus in any other geographical populations of O. rhinoceros collected from the South Pacific Islands and the Philippines. Analysis of the deduced RdRp amino acid sequences showed that the virus clustered with other Picorna-like viruses and separated from other members of family Dicistroviridae and Iflaviridae.

scholarly journals Transcriptome and microbiome of coconut rhinoceros beetle (Oryctes rhinoceros) larvae

BMC Genomics ◽  
2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Matan Shelomi ◽  
Shih-Shun Lin ◽  
Li-Yu Liu
Keyword(s):  
Pacific Islands ◽  
Plant Cell Wall ◽  
Fat Body ◽  
Molecular Data ◽  
Cell Wall Degrading Enzymes ◽  
Tropical Asia ◽  
Oryctes Rhinoceros ◽  
Rhinoceros Beetle ◽  
Microbial Symbionts ◽  
Decaying Wood

Abstract Background The coconut rhinoceros beetle, Oryctes rhinoceros, is a major pest of palm crops in tropical Asia and the Pacific Islands. Little molecular data exists for this pest, impeding our ability to develop effective countermeasures and deal with the species’ growing resistance to viral biocontrols. We present the first molecular biology analyses of this species, including a metagenomic assay to understand the microbiome of different sections of its digestive tract, and a transcriptomics assay to complement the microbiome data and to shed light on genes of interest like plant cell wall degrading enzymes and immunity and xenobiotic resistance genes. Results The gut microbiota of Oryctes rhinoceros larvae is quite similar to that of the termite gut, as both species feed on decaying wood. We found the first evidence for endogenous beta-1,4-endoglucanase in the beetle, plus evidence for microbial cellobiase, suggesting the beetle can degrade cellulose together with its gut microfauna. A number of antimicrobial peptides are expressed, particularly by the fat body but also by the midgut and hindgut. Conclusions This transcriptome provides a wealth of data about the species’ defense against chemical and biological threats, has uncovered several potentially new species of microbial symbionts, and significantly expands our knowledge about this pest.

Sign in / Sign up

Export Citation Format

Share Document