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1.
Nat Commun ; 14(1): 545, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36726015

RESUMO

Understanding the structural diversity of honeybee-infecting viruses is critical to maintain pollinator health and manage the spread of diseases in ecology and agriculture. We determine cryo-EM structures of T = 4 and T = 3 capsids of virus-like particles (VLPs) of Lake Sinai virus (LSV) 2 and delta-N48 LSV1, belonging to tetraviruses, at resolutions of 2.3-2.6 Å in various pH environments. Structural analysis shows that the LSV2 capsid protein (CP) structural features, particularly the protruding domain and C-arm, differ from those of other tetraviruses. The anchor loop on the central ß-barrel domain interacts with the neighboring subunit to stabilize homo-trimeric capsomeres during assembly. Delta-N48 LSV1 CP interacts with ssRNA via the rigid helix α1', α1'-α1 loop, ß-barrel domain, and C-arm. Cryo-EM reconstructions, combined with X-ray crystallographic and small-angle scattering analyses, indicate that pH affects capsid conformations by regulating reversible dynamic particle motions and sizes of LSV2 VLPs. C-arms exist in all LSV2 and delta-N48 LSV1 VLPs across varied pH conditions, indicating that autoproteolysis cleavage is not required for LSV maturation. The observed linear domino-scaffold structures of various lengths, made up of trapezoid-shape capsomeres, provide a basis for icosahedral T = 4 and T = 3 architecture assemblies. These findings advance understanding of honeybee-infecting viruses that can cause Colony Collapse Disorder.


Assuntos
Proteínas do Capsídeo , Vírus de RNA , Abelhas , Animais , Proteínas do Capsídeo/metabolismo , Capsídeo/metabolismo , Microscopia Crioeletrônica , Conformação Molecular , Montagem de Vírus
2.
Proc Natl Acad Sci U S A ; 120(6): e2212864120, 2023 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-36724259

RESUMO

Non-coding RNAs (ncRNAs) play important roles in host-pathogen interactions; oncogenic viruses like Kaposi's sarcoma herpesvirus (KSHV) employ ncRNAs to establish a latent reservoir and persist for the life of the host. We previously reported that KSHV infection alters a novel class of RNA, circular RNAs (circRNAs). CircRNAs are alternative splicing isoforms and regulate gene expression, but their importance in infection is largely unknown. Here, we showed that a human circRNA, hsa_circ_0001400, is induced by various pathogenic viruses, namely KSHV, Epstein-Barr virus, and human cytomegalovirus. The induction of circRNAs including circ_0001400 by KSHV is co-transcriptionally regulated, likely at splicing. Consistently, screening for circ_0001400-interacting proteins identified a splicing factor, PNISR. Functional studies using infected primary endothelial cells revealed that circ_0001400 inhibits KSHV lytic transcription and virus production. Simultaneously, the circRNA promoted cell cycle, inhibited apoptosis, and induced immune genes. RNA-pull down assays identified transcripts interacting with circ_0001400, including TTI1, which is a component of the pro-growth mTOR complexes. We thus identified a circRNA that is pro-growth and anti-lytic replication. These results support a model in which KSHV induces circ_0001400 expression to maintain latency. Since circ_0001400 is induced by multiple viruses, this novel viral strategy may be widely employed by other viruses.


Assuntos
Infecções por Vírus Epstein-Barr , Herpesvirus Humano 8 , Infecção Latente , Vírus de RNA , Sarcoma de Kaposi , Humanos , Herpesvirus Humano 8/genética , RNA Circular/genética , Sarcoma de Kaposi/genética , Células Endoteliais , Latência Viral/genética , Herpesvirus Humano 4/genética , RNA Viral/genética , RNA não Traduzido , Vírus de RNA/genética , Replicação Viral/genética , Regulação Viral da Expressão Gênica
3.
J Virol ; 97(1): e0138122, 2023 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-36625579

RESUMO

Although segmented negative-sense RNA viruses (SNSRVs) have been frequently discovered in various fungi, most SNSRVs reported only the large segments. In this study, we investigated the diversity of the mycoviruses in the phytopathogenic fungus Fusarium asiaticum using the metatranscriptomic technique. We identified 17 fungal single-stranded RNA (ssRNA) viruses including nine viruses within Mitoviridae, one each in Narnaviridae, Botourmiaviridae, Hypoviridae, Fusariviridae, and Narliviridae, two in Mymonaviridae, and one trisegmented virus temporarily named Fusarium asiaticum mycobunyavirus 1 (FaMBV1). The FaMBV1 genome comprises three RNA segments, large (L), medium (M), and small (S) with 6,468, 2,639, and 1,420 nucleotides, respectively. These L, M, and S segments putatively encode the L protein, glycoprotein, and nucleocapsid, respectively. Phylogenetic analysis based on the L protein showed that FaMBV1 is phylogenetically clustered with Alternaria tenuissima negative-stranded RNA virus 2 (AtNSRV2) and Sclerotinia sclerotiorum negative-stranded RNA virus 5 (SsNSRV5) but distantly related to the members of the family Phenuiviridae. FaMBV1 could be vertically transmitted by asexual spores with lower efficiency (16.7%, 2/42). Comparison between FaMBV1-free and -infected fungal strains revealed that FaMBV1 has little effect on hyphal growth, pathogenicity, and conidium production, and its M segment is dispensable for viral replication and lost during subculture and asexual conidiation. The M and S segments of AtNSRV2 and SsNSRV5 were found using bioinformatics methods, indicating that the two fungal NSRVs harbor trisegmented genomes. Our results provide a new example of the existence and evolution of the segmented negative-sense RNA viruses in fungi. IMPORTANCE Fungal segmented negative-sense RNA viruses (SNSRVs) have been frequently found. Only the large segment encoding RNA-dependent RNA polymerase (RdRp) has been reported in most fungal SNSRVs, except for a few fungal SNSRVs reported to encode nucleocapsids, nonstructural proteins, or movement proteins. Virome analysis of the Fusarium spp. that cause Fusarium head blight discovered a novel virus, Fusarium asiaticum mycobunyavirus 1 (FaMBV1), representing a novel lineage of the family Phenuiviridae. FaMBV1 harbors a trisegmented genome that putatively encodes RdRp, glycoproteins, and nucleocapsids. The putative glycoprotein was first described in fungal SNSRVs and shared homology with glycoprotein of animal phenuivirus but was dispensable for its replication in F. asiaticum. Two other trisegmented fungal SNSRVs that also encode glycoproteins were discovered, implying that three-segment bunyavirus infections may be common in fungi. These findings provide new insights into the ecology and evolution of SNSRVs, particularly those infecting fungi.


Assuntos
Micovírus , Vírus de RNA , Micovírus/genética , RNA Viral/genética , Filogenia , Vírus de RNA/genética , Glicoproteínas/genética , Genoma Viral , Fases de Leitura Aberta
4.
Biol Lett ; 19(1): 20220416, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36651030

RESUMO

The majority of invasive species are best known for their effects as predators. However, many introduced predators may also be substantial reservoirs for pathogens. Honey bee-associated viruses are found in various arthropod species including invasive ants. We examined how the globally invasive Argentine ant (Linepithema humile), which can reach high densities and infest beehives, is associated with pathogen dynamics in honey bees. Viral loads of deformed wing virus (DWV), which has been linked to millions of beehive deaths around the globe, and black queen cell virus significantly increased in bees when invasive ants were present. Microsporidian and trypanosomatid infections, which are more bee-specific, were not affected by ant invasion. The bee virome in autumn revealed that DWV was the predominant virus with the highest infection levels and that no ant-associated viruses were infecting bees. Viral spillback from ants could increase infections in bees. In addition, ant attacks could pose a significant stressor to bee colonies that may affect virus susceptibility. These viral dynamics are a hidden effect of ant pests, which could have a significant impact on disease emergence in this economically important pollinator. Our study highlights a perhaps overlooked effect of species invasions: changes in pathogen dynamics.


Assuntos
Vírus de RNA , Animais , Abelhas , Espécies Introduzidas
5.
Arch Virol ; 168(2): 66, 2023 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-36653596

RESUMO

The complete genome sequence of a novel single-stranded [+ ssRNA] positive-sense (+) RNA mycovirus, designated as "Pleurotus citrinopileatus ourmiavirus 1" (PcOV1), isolated from Pleurotus citrinopileatus strain CCMJ2141, was determined. The complete genome of PcOV1 is composed of 2,535 nucleotides. It contains a single open reading frame (ORF), which encodes a protein of 657 amino acids (aa) containing conserved domains of an RNA-dependent RNA polymerase (RdRp). Phylogenetic analysis based on RdRp sequences revealed that PcOV1 is a new member of the genus Ourmiavirus in the family Botourmiaviridae. This is the first virus from P. citrinopileatus to be characterized.


Assuntos
Micovírus , Vírus de RNA , RNA Viral/genética , Filogenia , Genoma Viral , RNA Polimerase Dependente de RNA/genética , Fases de Leitura Aberta , RNA de Cadeia Dupla
6.
PLoS Pathog ; 19(1): e1011061, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36656843

RESUMO

Varroa destructor is a cosmopolitan pest and leading cause of colony loss of the European honey bee. Historically described as a competent vector of honey bee viruses, this arthropod vector is the cause of a global pandemic of Deformed wing virus, now endemic in honeybee populations in all Varroa-infested regions. Our work shows that viral spread is driven by Varroa actively switching from one adult bee to another as they feed. Assays using fluorescent microspheres were used to indicate the movement of fluids in both directions between host and vector when Varroa feed. Therefore, Varroa could be in either an infectious or naïve state dependent upon the disease status of their host. We tested this and confirmed that the relative risk of a Varroa feeding depended on their previous host's infectiousness. Varroa exhibit remarkable heterogeneity in their host-switching behavior, with some Varroa infrequently switching while others switch at least daily. As a result, relatively few of the most active Varroa parasitize the majority of bees. This multiple-feeding behavior has analogs in vectorial capacity models of other systems, where promiscuous feeding by individual vectors is a leading driver of vectorial capacity. We propose that the honeybee-Varroa relationship offers a unique opportunity to apply principles of vectorial capacity to a social organism, as virus transmission is both vectored and occurs through multiple host-to-host routes common to a crowded society.


Assuntos
Vírus de RNA , Varroidae , Abelhas , Animais , Vetores Artrópodes
7.
Viruses ; 15(1)2023 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-36680240

RESUMO

Infection with Aspergillus fumigatus polymycovirus 1 (AfuPmV-1) weakens resistance of Aspergillus fumigatus common reference strain Af293 biofilms in intermicrobial competition with Pseudomonas aeruginosa. We compared the sensitivity of two infected and one virus-free Af293 strains to antifungal drugs. All three were comparably sensitive to drugs affecting fungal membranes (voriconazole, amphotericin) or cell wall glucan synthesis (micafungin, caspofungin). In contrast, forming biofilms of virus-free Af293 were much more resistant than AfuPmV-1-infected Af293 to nikkomycin Z (NikZ), a drug inhibiting chitin synthase. The IC50 for NikZ on biofilms was between 3.8 and 7.5 µg/mL for virus-free Af293 and 0.94-1.88 µg/mL for infected strains. The IC50 for the virus-free A. fumigatus strain 10AF was ~2 µg/mL in most experiments. NikZ also modestly affected the planktonic growth of infected Af293 more than the virus-free strain (MIC 50%, 2 and 4 µg/mL, respectively). Virus-free Af293 biofilm showed increased metabolism, and fungus growing as biofilm or planktonically showed increased growth compared to infected; these differences do not explain the resistance of the virus-free fungus to NikZ. In summary, AfuPmV-1 infection sensitized A. fumigatus to NikZ, but did not affect response to drugs commonly used against A. fumigatus infection. Virus infection had a greater effect on NikZ inhibition of biofilm than planktonic growth.


Assuntos
Antifúngicos , Vírus de RNA , Antifúngicos/farmacologia , Antifúngicos/metabolismo , Aspergillus fumigatus/fisiologia , Aminoglicosídeos/farmacologia , Aminoglicosídeos/metabolismo , Anfotericina B/metabolismo , Anfotericina B/farmacologia
8.
Virus Res ; 325: 199037, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36596382

RESUMO

A new double-stranded RNA (dsRNA) virus has been identified in the filamentous fungus Setosphaeria turcica f.sp. sorghi, whose genome consists of four segments (dsRNA1-4). Each dsRNA carries single open reading frame (ORF) flanked by 5' and 3' untranslated regions (UTRs) containing strictly conserved termini. The putative protein encoded by dsRNA1 showed 80.50% identity to the RNA-dependent RNA polymerase (RdRp) of the most closely related virus, Alternaria alternata chrysovirus 1 (AaCV1), belonging to the Chrysoviridae. dsRNA2 encodes the putative coat protein, while dsRNA3 and dsRNA4 respectively encode the hypothetical proteins of unknown functions. Phylogenetic analysis based on the RdRp protein indicated the virus clustered with members of the genus Betachrysovirus in the family Chrysoviridae. Based on the dsRNA profile, amino acid sequence comparisons, and phylogenetic analyses, the mycovirus is thought to be a new member of the family Chrysoviridae and designated as Setosphaeria turcica chrysovirus 1 (StCV1). Moreover, obvious differences were observed in the colony, mycelial and spore morphology between StCV1-infected and virus-cured strains of S. turcica f.sp. sorghi. StCV1 infection strongly reduced colony growth rate, spore production ability and virulence on host fungus. To our knowledge, this is the first report about mycovirus infecting S. turcica f.sp. sorghi and also the first chrysovirus infecting S. turcica.


Assuntos
Micovírus , Vírus de RNA , RNA Viral/genética , RNA Viral/metabolismo , Filogenia , RNA Polimerase Dependente de RNA/genética , RNA Polimerase Dependente de RNA/metabolismo , RNA de Cadeia Dupla/genética , Fases de Leitura Aberta , Genoma Viral , Micovírus/genética , Micovírus/metabolismo
9.
Virus Res ; 325: 199045, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36681193

RESUMO

The characterization of viruses from environmental samples could aid in our understanding of their ecological significance and potential for biotechnological exploitation. While there has been much focus on pathogenic fungi or commercially cultivated mushrooms, attention to viruses from wild Basidiomycota mushrooms is lacking. Therefore, in this study, we conducted viral screening of fungal mycelia isolated from wild basidiocarps using agarose gel electrophoresis (AGE) and fragmented and primer-ligated dsRNA sequencing (FLDS). Among the 51 isolates, seven isolates were detected with virus-like bands during the initial screening with AGE, but only five isolates were detected with viruses after long-term storage. Using the FLDS method, we obtained seven viral genome sequences, including five double-stranded RNA (dsRNA) viruses belonging to Partitiviridae and Curvulaviridae, one positive-sense single-stranded RNA (ssRNA) virus belonging to Endornaviridae and one negative-sense ssRNA virus belonging to Tulasviridae (Bunyavirales). All viruses characterized in this study are novel species. These findings greatly expanded our knowledge of the diversity of RNA viruses from environmental samples.


Assuntos
Agaricales , Micovírus , Vírus de RNA , RNA Viral/genética , Agaricales/genética , Japão , RNA de Cadeia Dupla/genética , Filogenia , Genoma Viral
10.
Arch Virol ; 168(2): 58, 2023 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-36617592

RESUMO

Phellodendron-associated higre-like virus (PaHLV) was identified in Phellodendron amurense Rupr. in China. Three near-full-length sequences of the viral genomic RNAs (RNA1-RNA3) were first obtained by RNA-seq, and their complete sequences were then determined by RT-PCR, 5'-RACE, and 3'-RACE. RNA1-3 of PaHLV were determined to be 8,183, 3,062, and 3,998 nucleotides (nt) in length, respectively, excluding the poly(A) tail. All of the viral proteins encoded by PaHLV shared the highest amino acid sequence identity (44.8-78.1%) with the unclassified kitavirid pistachio virus X (PiVX, MT334618-MT334620) from Iranian pistachio. Sequence comparisons and phylogenetic analysis also showed PiVX to be the closest relative of PaHLV and supported their inclusion in the genus Higrevirus, family Kitaviridae. Thus, PaHLV is proposed to be a member of a new species in this genus, for which we suggest the binomial name "Higrevirus amur".


Assuntos
Phellodendron , Vírus de RNA , Filogenia , Irã (Geográfico) , Vírus de RNA/genética , Vírus Satélites/genética , China , RNA Viral/genética , Genoma Viral
11.
Arch Virol ; 168(2): 34, 2023 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-36609790

RESUMO

A novel dsRNA mycovirus named Ilyonectria crassa alternavirus 1 (IcAV1) was found in Ilyonectria crassa isolate NW-FVA 1829. The fungus was isolated from an ash (Fraxinus excelsior L.) necrotic trunk disc infected with Hymenoscyphus fraxineus [(T. Kowalski) Baral, Queloz, Hosoya] causing ash dieback. The complete genome of IcAV1 is composed of three segments, each containing a single ORF on the positive-sense RNA. The extreme 5' UTRs of dsRNA 1 (3604 bp), dsRNA 2 (2547 bp), and dsRNA 3 (2518 bp) share a conserved hexadecamer sequence (5'-GGCTGTGTGTTTAGTT-3') and are capped. The 3' UTRs are polyadenylated. In silico analysis showed that the viral RdRP is encoded on dsRNA 1 and the capsid-protein subunits are encoded on dsRNA 3. Maximum-likelihood analysis of the aa sequence of the viral RdRP showed that IcAV1 clusters with alternaviruses from Fusarium spp., while the type member of the proposed family "Alternaviridae", Alternaria alternata virus 1 (AaV1), formed a clade together with Stemphylium lycopersici mycovirus (SlV). The function of the protein encoded on segment 2 is unknown. Based on its genome organization and its phylogenetic position, IcAV1 is suggested to be a new member of the proposed family "Alternaviridae". This is the first report of a mycovirus infecting I. crassa.


Assuntos
Micovírus , Vírus de RNA , Filogenia , Genoma Viral , RNA Polimerase Dependente de RNA/genética , RNA Viral/genética , Fases de Leitura Aberta , RNA de Cadeia Dupla/genética
12.
Arch Virol ; 168(2): 48, 2023 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-36609794

RESUMO

In July 2018, pepper plants (Capsicum annuum L.) with chlorotic leaves and fruits were observed in Kochi prefecture, Japan. High-throughput sequencing (HTS) identified the possible presence of an ophiovirus-like virus possessing three RNA segments in a chlorotic leaf. Using Sanger sequencing with primers designed based on the HTS results and a different source of RNA from the one used for HTS, the complete nucleotide sequences of three RNA segments encoding four proteins on their complementary strand were determined. The amino acid sequences of these four proteins showed similarity to those of the RNA-dependent RNA polymerase, RNA-silencing suppressor protein, movement protein, and coat protein, respectively, of ophioviruses, which are negative-sense single-stranded RNA viruses. However, the coat protein amino acid sequence of the virus found on pepper plants was no more than 61.9% identical to those of any known ophioviruses, which is lower than the species demarcation threshold of 85 %. Hence, we suggest that this virus, which we have named "pepper chlorosis associated virus" (PepCaV) should be considered a member of a new species in the genus Ophiovirus, for which we propose the name "Ophiovirus capsici". The results of phylogenetic analysis using coat protein amino acid sequences of PepCaV and other ophioviruses also supported this conclusion. PepCaV RNA was found to have conserved nucleotide sequences at both the 5' and 3' termini of the different RNA segments, and the conserved terminal nucleotide sequences were predicted to form a self-complementary double-stranded region, resulting in a panhandle structure in each of the genomic RNAs.


Assuntos
Capsicum , Vírus de RNA , Japão , Filogenia , Vírus de RNA/genética , RNA Viral/genética
13.
Artigo em Inglês | MEDLINE | ID: mdl-36651466

RESUMO

New viruses of the Picornavirales order have been discovered with the increase in the number of sequences obtained by high-throughput sequencing, as well as human stool-associated RNA virus (husavirus [HuV]), found in human stool samples. However, there is much to be clarified about HuV. Its cellular host, evolutionary history, and other biological characteristics are still unknown. Therefore, samples collected from human beings and environmental samples in a watershed in Southern Brazil were processed for the metagenomic library. Upon metagenomic analysis, we identified a HuV (husavirus LMM_67754 OP019707) genome with 8,846 bp, which was reported for the first time in Southern Brazil. The new genome presents only 37% of nucleotide identity with Brazilian strains and more than 90% with genomes from China, Vietnam, Venezuela, and the Netherlands. The HuV phylogeny presents significant differences among genomes, probably because multiple introductions of the virus may have occurred. Many questions still need to be answered about HuV. Therefore, more sequences and studies on this virus are necessary to improve the comprehension of the unknown origin of Picornavirales.


Assuntos
Genoma Viral , Vírus de RNA , Humanos , Brasil , Genoma Viral/genética , Filogenia , Vírus de RNA/genética
14.
Proc Natl Acad Sci U S A ; 120(5): e2217412120, 2023 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-36693094

RESUMO

Positive-strand RNA viruses replicate their genomes in virus-induced membrane vesicles, and the resulting RNA replication complexes are a major target for virus control. Nodavirus studies first revealed viral RNA replication proteins forming a 12-fold symmetric "crown" at the vesicle opening to the cytosol, an arrangement recently confirmed to extend to distantly related alphaviruses. Using cryoelectron microscopy (cryo-EM), we show that mature nodavirus crowns comprise two stacked 12-mer rings of multidomain viral RNA replication protein A. Each ring contains an ~19 nm circle of C-proximal polymerase domains, differentiated by strikingly diverged positions of N-proximal RNA capping/membrane binding domains. The lower ring is a "proto-crown" precursor that assembles prior to RNA template recruitment, RNA synthesis, and replication vesicle formation. In this proto-crown, the N-proximal segments interact to form a toroidal central floor, whose 3.1 Å resolution structure reveals many mechanistic details of the RNA capping/membrane binding domains. In the upper ring, cryo-EM fitting indicates that the N-proximal domains extend radially outside the polymerases, forming separated, membrane-binding "legs." The polymerase and N-proximal domains are connected by a long linker accommodating the conformational switch between the two rings and possibly also polymerase movements associated with RNA synthesis and nonsymmetric electron density in the lower center of mature crowns. The results reveal remarkable viral protein multifunctionality, conformational flexibility, and evolutionary plasticity and insights into (+)RNA virus replication and control.


Assuntos
Vírus de RNA , Proteínas Virais , Proteínas Virais/genética , Proteínas Virais/metabolismo , Microscopia Crioeletrônica , Vírus de RNA/genética , RNA Viral/genética , RNA Viral/metabolismo , Replicação Viral/genética
15.
Arch Virol ; 168(2): 75, 2023 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-36707487

RESUMO

Here, we describe a novel mycovirus, tentatively designated as "Rhizoctonia solani fusarivirus 6" (RsFV6), which was discovered in Rhizoctonia solani AG-3 PT strain 3P-2-2. The virus has a single-stranded positive-sense RNA (+ssRNA) genome of 6141 nucleotides containing two open reading frames (ORFs) and a poly(A) tail. ORF1 encodes a large polypeptide of 1,862 amino acids (aa) with conserved RNA-dependent RNA polymerase (RdRp) and helicase (Hel) domains. ORF2 encodes a putative 167-aa protein of unknown function. BLASTp searches revealed that the ORF1-encoded polypeptide showed the highest sequence similarity (70.67% identity) to that of Rhizoctonia solani fusarivirus 3 (RsFV3), which was isolated from Rhizoctonia solani AG-2-2LP. Multiple sequence alignments and phylogenetic analysis based on RdRp and Hel sequences indicated that RsFV6 could be a novel member of the genus Alphafusarivirus family Fusariviridae.


Assuntos
Micovírus , Vírus de RNA , RNA Viral/genética , Filogenia , Genoma Viral , Rhizoctonia/genética , RNA Polimerase Dependente de RNA/genética , Micovírus/genética , Fases de Leitura Aberta
16.
Genes (Basel) ; 14(1)2023 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-36672929

RESUMO

The red imported fire ant Solenopsis invicta Buren (fire ant hereafter) is a global pest that inflicts billions of dollars in damages to the United States economy and poses a major threat on a global scale. Concerns with the broad-spectrum application of insecticides have facilitated the hunt for natural enemy-mediated controls. One of these, the virus Solenopsis invicta virus-3 (SINV-3 hereafter) is exceptionally virulent in laboratory settings. However, despite high mortality rates in the laboratory and documented widespread SINV-3 prevalence in the southern United States, the fire ant remains a major pest. To explore this paradox, we document the immune response elicited by the fire ant when infected with SINV-3. We sequence the fire ant transcriptome prior to and following infection with SINV-3, and identify and discuss in detail genes in immune response pathways differentially expressed following infection with SINV-3. This information provides insights into genes and pathways involved in the SINV-3 infection response in the fire ant and offers avenues to pursue, to suppress key immune response genes and force the fire ant to succumb to SINV-3 infection in the field.


Assuntos
Formigas , Vírus de RNA , Animais , Vírus de RNA/genética , Formigas/genética , Imunidade Inata/genética , Expressão Gênica
17.
Nat Microbiol ; 8(1): 135-149, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36604511

RESUMO

Aedes aegypti and A. albopictus mosquitoes are the main vectors for dengue virus (DENV) and other arboviruses, including Zika virus (ZIKV). Understanding the factors that affect transmission of arboviruses from mosquitoes to humans is a priority because it could inform public health and targeted interventions. Reasoning that interactions among viruses in the vector insect might affect transmission, we analysed the viromes of 815 urban Aedes mosquitoes collected from 12 countries worldwide. Two mosquito-specific viruses, Phasi Charoen-like virus (PCLV) and Humaita Tubiacanga virus (HTV), were the most abundant in A. aegypti worldwide. Spatiotemporal analyses of virus circulation in an endemic urban area revealed a 200% increase in chances of having DENV in wild A. aegypti mosquitoes when both HTV and PCLV were present. Using a mouse model in the laboratory, we showed that the presence of HTV and PCLV increased the ability of mosquitoes to transmit DENV and ZIKV to a vertebrate host. By transcriptomic analysis, we found that in DENV-infected mosquitoes, HTV and PCLV block the downregulation of histone H4, which we identify as an important proviral host factor in vivo.


Assuntos
Aedes , Arbovírus , Vírus da Dengue , Dengue , Vírus de Insetos , Vírus de RNA , Infecção por Zika virus , Zika virus , Animais , Humanos , Zika virus/genética , Vírus de Insetos/fisiologia , Vírus da Dengue/genética , Mosquitos Vetores , Arbovírus/genética
18.
Nat Microbiol ; 8(1): 162-173, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36604510

RESUMO

The increasing prevalence and expanding distribution of tick-borne viruses globally have raised health concerns, but the full repertoire of the tick virome has not been assessed. We sequenced the meta-transcriptomes of 31 different tick species in the Ixodidae and Argasidae families from across mainland China, and identified 724 RNA viruses with distinctive virome compositions among genera. A total of 1,801 assembled and complete or nearly complete viral genomes revealed an extensive diversity of genome architectures of tick-associated viruses, highlighting ticks as a reservoir of RNA viruses. We examined the phylogenies of different virus families to investigate virome evolution and found that the most diverse tick-associated viruses are positive-strand RNA virus families that demonstrate more ancient divergence than other arboviruses. Tick-specific viruses are often associated with only a few tick species, whereas virus clades that can infect vertebrates are found in a wider range of tick species. We hypothesize that tick viruses can exhibit both 'specialist' and 'generalist' evolutionary trends. We hope that our virome dataset will enable much-needed research on vertebrate-pathogenic tick-associated viruses.


Assuntos
Vírus de RNA , Carrapatos , Vírus , Animais , Vírus de RNA/genética , Genoma Viral/genética , RNA
19.
Arch Virol ; 168(1): 28, 2023 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-36598574

RESUMO

A new sobemovirus, which we have named "mimosa mosaic virus" (MimMV), was found by high-throughput sequencing and isolated from a mimosa (Mimosa sensitiva L.) plant. The genome sequence was confirmed by Sanger sequencing and comprises 4595 nucleotides. Phylogenetic analysis based on the predicted amino acid (aa) sequences of the P2b protein (encoded by ORF2b) and the coat protein showed 52.7% and 31.8% aa sequence identity, respectively, to those of blueberry shoestring virus. The complete genome sequence of MimMV was less than 47% identical to those of other sobemoviruses. These data suggest that MimMV is a member of a new species in the genus Sobemovirus, for which the binomial name "Sobemovirus mimosae" is proposed.


Assuntos
Mimosa , Vírus do Mosaico , Vírus de RNA , Mimosa/genética , Filogenia , Genoma Viral , Vírus de RNA/genética , Vírus do Mosaico/genética , Doenças das Plantas , Fases de Leitura Aberta , RNA Viral/genética , RNA Viral/química
20.
Arch Virol ; 168(1): 15, 2023 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-36593368

RESUMO

Phaeobotryon rhois is an important pathogenic fungus that causes dieback and canker disease of woody hosts. A novel mycovirus, tentatively named "Phaeobotryon rhois victorivirus 1" (PrVV1), was identified in P. rhois strain SX8-4. The PrVV1 has a double-stranded RNA (dsRNA) genome that is 5,224 base pairs long and contains two open reading frames (ORF1 and ORF2), which overlap at a AUGA sequence. ORF1 encodes a polypeptide of 786 amino acids (aa) that contains the conserved coat protein (CP) domain of victoriviruses, while ORF2, encodes a large polypeptide of 826 aa that contains the conserved RNA-dependent RNA polymerase (RdRp) domain of victoriviruses. Our analysis of genomic structure, homology, and phylogeny indicated that PrVV1 is a novel member of the genus Victorivirus in the family Totiviridae. This is the first report of the complete genome sequence of a victorivirus that infects P. rhois.


Assuntos
Ascomicetos , Micovírus , Vírus de RNA , Totiviridae , Proteínas Virais/genética , Proteínas Virais/química , Ascomicetos/genética , Genômica , Genoma Viral , Filogenia , Fases de Leitura Aberta , RNA de Cadeia Dupla , RNA Viral/genética , RNA Viral/química , Micovírus/genética , Vírus de RNA/genética
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