Circular Single-stranded DNA Viruses Research Articles

Feline Stool-Associated Circular DNA Virus (FeSCV) in Diarrheic Cats in China.

Feline stool-associated circular DNA virus (FeSCV) is an unclassified circular replication-associated protein-encoding single-stranded (CRESS) DNA virus that was discovered in cats in Japan in 2018. Few studies on the genomic characteristics and prevalence of FeSCV have been conducted. To investigate whether FeSCV has been circulating in domestic cats in Guangdong, China, fecal samples were collected from cats with diarrhea in an animal hospital in 2018 to promote research on FeSCV. The FeSCV genome was obtained by PCR amplification and sequencing, and the detected virus was named PY4 (GenBank No. MT732515). The genome of PY4 was 2,034 nt in size, which was 12 nt smaller than the reported genome of Japanese FeSCV strains (KU7, KU8, KU9, KU14) (2,046 nt). The PY4 strain shared 95.1 ~ 95.5% homology with Japanese FeSCV strains. Notably, the Cap protein of PY4 was mutated at 15 amino acid sites, and the PY4 genome contained a unique open reading frame 3. In addition, there were two additional base insertions in the stem-loop structure of PY4, and the nucleotide homology of the spacer region was not high. A phylogenetic tree based on Rep proteins showed that PY4, Japanese FeSCVs and rodent stool-associated circular viruses (RodSCVs) clustered together, suggesting that they might share a similar origin in their phylogenetic evolution. In this study, samples collected in Guangzhou, China, in 2018 were subjected to an etiological investigation, and 20% (2/10) of the samples were positive for FeSCV. The ORFs, stem-loop structures, Cap proteins and intergenic region sequences of PY4 were significantly different from those reported in Japan. This is the first report of FeSCV in domestic cats with diarrhea in China, and further epidemiological studies are urgently needed to assess the impact of the virus on cats.

Characterization of a novel genomovirus in the phytopathogenic fungus Botrytis cinerea

This study characterized a single-stranded circular DNA virus in Botrytis cinerea—namely, Botrytis cinerea genomovirus 1 (BcGV1). The genome of BcGV1 was 1710 nucleotides (nts) long, possessing two ORFs, encoding a putative replication initiation protein (Rep) and a hypothetical protein. The Rep contained seven conserved motifs. The two ORFs were separated by two intergenic regions; the large intergenic region (LIR) contained 259 nts while the small intergenic region (SIR) contained 95 nts. A nonanucleotide, TAACAGTAC, in the LIR was predicted to be associated with the initiation of viral replication. Based on the phylogenetic tree constructed by Reps, BcGV1 belongs to the family Genomoviridae, forming an independent branch, indicating that BcGV1 may belong to a new genus. BcGV1 could be detected in 6.7% of tested B. cinerea strains, suggesting that BcGV1 may be widely distributed in the Chinese B. cinerea population.

Detection and Genetic Characterization of Viruses Present in Free-Ranging Snow Leopards Using Next-Generation Sequencing.

Snow leopards inhabit the cold, arid environments of the high mountains of South and Central Asia. These living conditions likely affect the abundance and composition of microbes with the capacity to infect these animals. It is important to investigate the microbes that snow leopards are exposed to detect infectious disease threats and define a baseline for future changes that may impact the health of this endangered felid. In this work, next-generation sequencing is used to investigate the fecal (and in a few cases serum) virome of seven snow leopards from the Tost Mountains of Mongolia. The viral species to which the greatest number of sequences reads showed high similarity was rotavirus. Excluding one animal with overall very few sequence reads, four of six animals (67%) displayed evidence of rotavirus infection. A serum sample of a male and a rectal swab of a female snow leopard produced sequence reads identical or closely similar to felid herpesvirus 1, providing the first evidence that this virus infects snow leopards. In addition, the rectal swab from the same female also displayed sequence reads most similar to feline papillomavirus 2, which is the first evidence for this virus infecting snow leopards. The rectal swabs from all animals also showed evidence for the presence of small circular DNA viruses, predominantly Circular Rep-Encoding Single-Stranded (CRESS) DNA viruses and in one case feline anellovirus. Several of the viruses implicated in the present study could affect the health of snow leopards. In animals which are under environmental stress, for example, young dispersing individuals and lactating females, health issues may be exacerbated by latent virus infections.

Diverse genomoviruses representing twenty-nine species identified associated with plants.

Genomoviruses (family Genomoviridae) are circular single-stranded DNA viruses that have been mainly identified through metagenomics studies in a wide variety of samples from various environments. Here, we describe 98 genomes of genomoviruses found associated with members of 19 plant families from Australia, Brazil, France, South Africa and the USA. These 98 genomoviruses represent 29 species, 26 of which are new, in the genera Gemykolovirus (n = 37), Gemyduguivirus (n = 9), Gemygorvirus (n = 8), Gemykroznavirus (n = 6), Gemycircularvirus (n = 21) and Gemykibivirus (n = 17).

Unveiling Crucivirus Diversity by Mining Metagenomic Data.

The discovery of cruciviruses revealed the most explicit example of a common protein homologue between DNA and RNA viruses to date. Cruciviruses are a novel group of circular Rep-encoding single-stranded DNA (ssDNA) (CRESS-DNA) viruses that encode capsid proteins that are most closely related to those encoded by RNA viruses in the family Tombusviridae The apparent chimeric nature of the two core proteins encoded by crucivirus genomes suggests horizontal gene transfer of capsid genes between DNA and RNA viruses. Here, we identified and characterized 451 new crucivirus genomes and 10 capsid-encoding circular genetic elements through de novo assembly and mining of metagenomic data. These genomes are highly diverse, as demonstrated by sequence comparisons and phylogenetic analysis of subsets of the protein sequences they encode. Most of the variation is reflected in the replication-associated protein (Rep) sequences, and much of the sequence diversity appears to be due to recombination. Our results suggest that recombination tends to occur more frequently among groups of cruciviruses with relatively similar capsid proteins and that the exchange of Rep protein domains between cruciviruses is rarer than intergenic recombination. Additionally, we suggest members of the stramenopiles/alveolates/Rhizaria supergroup as possible crucivirus hosts. Altogether, we provide a comprehensive and descriptive characterization of cruciviruses.IMPORTANCE Viruses are the most abundant biological entities on Earth. In addition to their impact on animal and plant health, viruses have important roles in ecosystem dynamics as well as in the evolution of the biosphere. Circular Rep-encoding single-stranded (CRESS) DNA viruses are ubiquitous in nature, many are agriculturally important, and they appear to have multiple origins from prokaryotic plasmids. A subset of CRESS-DNA viruses, the cruciviruses, have homologues of capsid proteins encoded by RNA viruses. The genetic structure of cruciviruses attests to the transfer of capsid genes between disparate groups of viruses. However, the evolutionary history of cruciviruses is still unclear. By collecting and analyzing cruciviral sequence data, we provide a deeper insight into the evolutionary intricacies of cruciviruses. Our results reveal an unexpected diversity of this virus group, with frequent recombination as an important determinant of variability.

Highly Sensitive Virome Characterization of Aedes aegypti and Culex pipiens Complex from Central Europe and the Caribbean Reveals Potential for Interspecies Viral Transmission.

Mosquitoes are the most important vectors for arthropod-borne viral diseases. Mixed viral infections of mosquitoes allow genetic recombination or reassortment of diverse viruses, turning mosquitoes into potential virologic mixing bowls. In this study, we field-collected mosquitoes of different species (Aedes aegypti and Culex pipiens complex), from different geographic locations and environments (central Europe and the Caribbean) for highly sensitive next-generation sequencing-based virome characterization. We found a rich virus community associated with a great diversity of host species. Among those, we detected a large diversity of novel virus sequences that we could predominately assign to circular Rep-encoding single-stranded (CRESS) DNA viruses, including the full-length genome of a yet undescribed Gemykrogvirus species. Moreover, we report for the first time the detection of a potentially zoonotic CRESS-DNA virus (Cyclovirus VN) in mosquito vectors. This study expands the knowledge on virus diversity in medically important mosquito vectors, especially for CRESS-DNA viruses that have previously been shown to easily recombine and jump the species barrier.

Geminivirus Resistance: A Minireview.

A continuing challenge to crop production worldwide is the spectrum of diseases caused by geminiviruses, a large family of small circular single-stranded DNA viruses. These viruses are quite diverse, some containing mono- or bi-partite genomes, and infecting a multitude of monocot and dicot plants. There are currently many efforts directed at controlling these diseases. While some of the methods include controlling the insect vector using pesticides or genetic insect resistance (Rodríguez-López et al., 2011), this review will focus on the generation of plants that are resistant to geminiviruses themselves. Genetic resistance was traditionally found by surveying the wild relatives of modern crops for resistance loci; this method is still widely used and successful. However, the quick rate of virus evolution demands a rapid turnover of resistance genes. With better information about virus-host interactions, scientists are now able to target early stages of geminivirus infection in the host, preventing symptom development and viral DNA accumulation.

A New Method to Obtain the Complete Genome Sequence of Multiple-Component Circular ssDNA Viruses by Transcriptome Analysis.

Circular single-stranded DNA (ssDNA) viruses are widely distributed globally, infecting diverse hosts ranging from bacteria, archaea, and eukaryotes. Among these, the genome of Banana bunchy top virus (BBTV) comprises at least six circular, ssDNA components that are ∼1 kb in length. Its genome is usually amplified and obtained at the DNA level. However, RNA-based techniques to obtain the genome sequence of such multi-component viruses have not been reported. In this study, transcriptome sequencing analysis showed that the full-length of BBTV each genomic component was transcribed into viral mRNA (vmRNA). Accordingly, the near-complete genome of BBTV B2 isolate was assembled using transcriptome sequencing data from virus-infected banana leaves. Assembly analysis of BBTV-derived reads indicated that the full-length sequences were obtained for DNA-R, DNA-U3, DNA-S, DNA-M, DNA-N, NewS2, and Sat4 components, while two gaps (73 and 25 nt) missing in the DNA-C component which was further filled by reverse transcription-PCR (RT-PCR). The RT-qPCR analysis indicated that the vmRNA levels of coding regions were 3.19–103.53 folds higher than those of non-coding regions, implying that the integrity of genome assembly depended on the transcription level of non-coding region. In conclusion, this study proposes a new approach to obtain the genome of nanovirids, and provides insights for studying the transcriptional mechanism of the family Nanoviridae, Genomoviridae, and Geminiviridae.

Virome of crab-eating (Cerdocyon thous) and pampas foxes (Lycalopex gymnocercus) from southern Brazil and Uruguay

Crab-eating (Cerdocyon thous) and Pampas foxes (Lycalopex gymnocercus) are wild canids distributed in South America. Domestic dogs (Canis lupus familiaris) and wild canids may share viral pathogens, including rabies virus (RABV), canine distemper virus (CDV), and canine parvovirus 2 (CPV-2). To characterize the virome of these wild canid species, the present work evaluated the spleen and mesenteric lymph node virome of 17 crab-eating and five Pampas foxes using high-throughput sequencing (HTS). Organ samples were pooled and sequenced using an Illumina MiSeq platform. Additional PCR analyses were performed to identify the frequencies and host origin for each virus detected by HTS. Sequences more closely related to the Paramyxoviridae, Parvoviridae and Anelloviridae families were detected, as well as circular Rep-encoding single-stranded (CRESS) DNA viruses. CDV was found only in crab-eating foxes, whereas CPV-2 was found in both canid species; both viruses were closely related to sequences reported in domestic dogs from southern Brazil. Moreover, the present work reported the detection of canine bocavirus (CBoV) strains that were genetically divergent from CBoV-1 and 2 lineages. Finally, we also characterized CRESS DNA viruses and anelloviruses with marked diversity. The results of this study contribute to the body of knowledge regarding wild canid viruses that can potentially be shared with domestic canids or other species.

A novel circular Rep-encoding single-stranded DNA virus detected in Agrotis ipsilon (Lepidoptera: Noctuidae) in China.

Long-distance migratory insects carry microorganisms that can potentially play a crucial role in the life cycles of their hosts. Here, we used Illumina and Sanger sequencing to determine the complete genome sequence of a novel circular Rep-encoding single-stranded (ss) DNA virus from an important migratory pest, Agrotis ipsilon (Hufnagel). The full genome of this new virus is about 2, 242 nt in length and shares 55-75% genome-wide pairwise sequence identity with members of the family Genomoviridae but 91% nucleotide sequence identity with finch-associated genomovirus 3 isolate S30P_D, which is tentatively abbreviated "FaGmV-3". Viral infection rates in A. ipsilon from Yantai, Langfang and Xinxiang were 4.5% (n = 88), 11.8% (n = 85) and 0% (n = 35), respectively. Phylogenetic analysis based on the deduced amino acid sequence of Rep indicated that the Agrotis ipsilon-associated virus is closely related to members of the genus Gemykibivirus, and we propose it to be a new member of this genus. Hence, it is tentatively named "Agrotis ipsilon-associated genomovirus" (AiGmV).

Novel smacoviruses identified in the faeces of two wild felids: North American bobcat and African lion.

Smacoviruses are small circular single-stranded DNA viruses that appear to be prevalent in faeces of a range of animals and have also been found in a few insect species. In this study, we report the first viral genomes from faeces of free-roaming wild felids on two continents. Two smacoviruses were recovered from the faeces of two North American bobcats (Lynx rufus), and one was recovered from an African lion (Panthera leo). All three genomes are genetically different, sharing 59-69% genome-wide sequence identity to other smacoviruses. These are the first full smacovirus genome sequences associated with a large top-end feline predator, and their presence in these samples suggests that feline faeces are a natural niche for the organisms that these viruses infect.Electronic supplementary materialThe online version of this article (10.1007/s00705-019-04329-3) contains supplementary material, which is available to authorized users.

Novel Circular Rep-Encoding Single-Stranded DNA Viruses Detected in Treated Wastewater.

Here, we present the complete genome sequences of three circular replication-associated protein (Rep)-encoding single-stranded DNA (CRESS DNA) viruses detected in secondary treated and disinfected wastewater effluent. The discovered viruses, named wastewater CRESS DNA virus (WCDV)-1 to -3, represent novel viral species that seem to persist in wastewater effluent.

Discovery and genetic characterization of diverse smacoviruses in Zambian non-human primates

The Smacoviridae has recently been classified as a family of small circular single-stranded DNA viruses. An increasing number of smacovirus genomes have been identified exclusively in faecal matter of various vertebrate species and from insect body parts. However, the genetic diversity and host range of smacoviruses remains to be fully elucidated. Herein, we report the genetic characterization of eleven circular replication-associated protein (Rep) encoding single-stranded (CRESS) DNA viruses detected in the faeces of Zambian non-human primates. Based on pairwise genome-wide and amino acid identities with reference smacovirus species, ten of the identified CRESS DNA viruses are assigned to the genera Porprismacovirus and Huchismacovirus of the family Smacoviridae, which bidirectionally encode two major open reading frames (ORFs): Rep and capsid protein (CP) characteristic of a type IV genome organization. The remaining unclassified CRESS DNA virus was related to smacoviruses but possessed a genome harbouring a unidirectionally oriented CP and Rep, assigned as a type V genome organization. Moreover, phylogenetic and recombination analyses provided evidence for recombination events encompassing the 3′-end of the Rep ORF in the unclassified CRESS DNA virus. Our findings increase the knowledge of the known genetic diversity of smacoviruses and highlight African non-human primates as carrier animals.

Banana bunchy top virus (BBTV) nuclear shuttle protein interacts and re-distributes BBTV coat protein in Nicotiana benthamiana.

Banana bunchy top virus (BBTV) is a circular single-stranded DNA virus with multi-components. The knowledge about interaction between viral proteins and pathogenesis mechanism of BBTV remains unclear. In this study, the coat protein gene (CP, ORF 516bp) and nuclear shuttle protein gene (NSP, ORF 465bp) from BBTV B2 isolate of the Southeast-Asia group were cloned. The intracellular localization analysis showed the CP locates in the cell nucleus of tobacco cells, while the NSP distributes in the cell nucleus and cytoplasm. Co-localization analysis indicated the NSP itself does not change distribution, but CP re-distributes to the cell nucleus and cytoplasm, suggesting that NSP interacts with CP and re-locates the CP in the cell. The interaction between CP and NSP was further verified by co-immunoprecipitation (Co-IP) in tobacco protoplasts. The study will help us to understand the interaction between viral proteins and pathogenesis mechanism of BBTV in host plants.

Chickpea chlorotic dwarf virus: An Emerging Monopartite Dicot Infecting Mastrevirus.

Chickpea stunt disease (CSD), caused by Chickpea chlorotic dwarf virus (CpCDV) is a threat to chickpea production leading to yield losses of 75–95%. Chickpea chlorotic dwarf virus is a monopartite, single-stranded circular DNA virus in the genus Mastrevirus and family Geminiviridae. It is transmitted by Orosius albicinctus in a circulative (persistent) and nonpropagative manner. Symptoms of CSD include very small leaves, intense discoloration (yellowing (kabuli type) and reddening (desi type)), and bushy stunted appearance of the plant. Presently, CpCDVs occurs in Africa, Asia, Australia, and the Middle East, causing extensive losses on economically important crops in in the families Fabaceae, Asteraceae, Amaranthaceae, Brassicaceae, Cucurbitaceae, Caricaceae, Chenopodiaceae, Leguminosae, Malvaceae, Pedaliaceae, and Solanaceae. High frequency of recombinations has played a significant role in the wide host range, diversification, and rapid evolution of CpCDVs. This review highlights the extensive research on the CpCDV genome diversity, host range, plant–virus–insect interactions, and RNA interference-based resistance of CpCDV, providing new insights into the host adaptation and virus evolution.

Molecular Characterization of a Novel Begomovirus Infecting Malva (Gaya guerkeana K. Schum.)

The genus Begomovirus (family Geminirvidae) comprises circular single-stranded DNA viruses that infect both cultivated and non-cultivated hosts, being transmitted by the insect vector Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae). This study aimed to conduct the molecular characterization of a novel begomovirus infecting the non-cultivated plant Gaya guerkeana K. Schum. (Malvaceae). A leaf sample of G. guerkeana was collected in the State of Pernambuco, Brazil, in 2010. Viral genomic components were amplified via RCA, cloned, and commercially sequenced. The full-length DNA-A sequence was used for phylogenetic analysis and pairwise comparisons with other previously reported begomoviruses. The begomovirus DNA-A from G. guerkeana was most closely related to the Sida mottle Alagoas virus (SiMoAV, JX871386), having 84.8% nucleotide identity. Using the ≥ 91% identity criteria for DNA-A established by the Geminivirus Study Group of the International Committee on Taxonomy of Viruses, this isolate was considered a putative new begomovirus species, and the name Gaya yellow mosaic virus (GaYMV) is suggested. The GaYMV isolate grouped with SiMoAV and other begomoviruses infecting Sida spp. from the State of Alagoas, Brazil. This is the first report of a begomovirus infecting G. guerkeana, indicating that this non-cultivated plant can act as a reservoir/source of begomoviruses.

Synaptogyrin-2 influences replication of Porcine circovirus 2.

Porcine circovirus 2 (PCV2) is a circular single-stranded DNA virus responsible for a group of diseases collectively known as PCV2 Associated Diseases (PCVAD). Variation in the incidence and severity of PCVAD exists between pigs suggesting a host genetic component involved in pathogenesis. A large-scale genome-wide association study of experimentally infected pigs (n = 974), provided evidence of a host genetic role in PCV2 viremia, immune response and growth during challenge. Host genotype explained 64% of the phenotypic variation for overall viral load, with two major Quantitative Trait Loci (QTL) identified on chromosome 7 (SSC7) near the swine leukocyte antigen complex class II locus and on the proximal end of chromosome 12 (SSC12). The SNP having the strongest association, ALGA0110477 (SSC12), explained 9.3% of the genetic and 6.2% of the phenotypic variance for viral load. Dissection of the SSC12 QTL based on gene annotation, genomic and RNA-sequencing, suggested that a missense mutation in the SYNGR2 (SYNGR2 p.Arg63Cys) gene is potentially responsible for the variation in viremia. This polymorphism, located within a protein domain conserved across mammals, results in an amino acid variant SYNGR2 p.63Cys only observed in swine. PCV2 titer in PK15 cells decreased when the expression of SYNGR2 was silenced by specific-siRNA, indicating a role of SYNGR2 in viral replication. Additionally, a PK15 edited clone generated by CRISPR-Cas9, carrying a partial deletion of the second exon that harbors a key domain and the SYNGR2 p.Arg63Cys, was associated with a lower viral titer compared to wildtype PK15 cells (>24 hpi) and supernatant (>48hpi)(P < 0.05). Identification of a non-conservative substitution in this key domain of SYNGR2 suggests that the SYNGR2 p.Arg63Cys variant may underlie the observed genetic effect on viral load.

Evaluation of the serum virome in calves persistently infected with Pestivirus A, presenting or not presenting mucosal disease

Bovine viral diarrhea virus 1, reclassified as Pestivirus A, causes an economically important cattle disease that is distributed worldwide. Pestivirus A may cause persistent infection in that calves excrete the virus throughout their lives, spreading the infection in the herd. Many persistently infected (PI) calves die in the first 2years of life from mucosal disease (MD) or secondary infections, probably as a consequence of virus-induced immune depression. Here, high-throughput sequencing (HTS) was applied for evaluation of the total virome in sera of (i) PI calves displaying clinically apparent MD (n = 8); (ii) PI calves with no signs of MD (n = 8); and (iii) control, Pestivirus A-free calves (n = 8). All the groups were collected at the same time and from the same herd. Serum samples from calves in each of the groups were pooled, submitted to viral RNA/DNA enrichment, and sequenced by HTS. Viral genomes of Pestivirus A, Ungulate erythroparvovirus 1, bosavirus (BosV), and hypothetical circular Rep-encoding single-stranded DNA (CRESS-DNA) viruses were identified. Specific real-time PCR assays were developed to determine the frequency of occurrence of such viruses in each of the groups. The absolute number of distinct viral genomes detected in both PI calf groups was higher than in the control group, as revealed by higher number of reads, contigs, and genomes, representing a wider range of taxons. Genomes representing members of the family Parvoviridae, such as U. erythroparvovirus 1 and BosV, were most frequently detected in all the three groups of calves. Only in MD-affected PI calves, we found two previously unreported Hypothetical single-stranded DNA genomes clustered along with CRESS-DNA viruses. These findings reveal that parvoviruses were the most frequently detected viral genomes in cattle serum; its frequency of detection bears no statistical correlation with the status of calves in relation to Pestivirus A infection, since clinically normal or MD-affected/non-affected PI calves were infected with similar U. erythroparvovirus 1 genome loads. Moreover, MD-affected PI calves were shown to support viremia of CRESS-DNA viral genomes; however, the meaning of such correlation remains to be established.

Prevalence and Genotyping of Torque Teno Virus in HBV/HIV and Chronic HBV Patients in Iran

Background:Torque teno virus (TTV) was the first human Anelloviridae detected in a Japanese patient with an unknown type of hepatitis in 1997. TTV is by far the first known single-stranded circular DNA virus infecting human. In spite of its widespread nature in human population, its pathogenesis is still unclear. In addition, information regarding TTV infection in Iranian population is limited. Therefore, we attempted to determine the prevalence and genotype ofTTV in three groups:HIV/HBV patients, chronic hepatitis B patients, and healthy individuals.Methods:The presence of TTV DNA in sera was investigated using PCR. The primer sets encompassing two 5’-UTR and N22 regions were used, and the positive products were collected for sequencing. Phylogenetic tree was generated based on N22 region and using the MEGA 7 software.Results:TTV DNA was detected in 452 patients with HIV/HBV and chronic hepatitis B, as well as in healthy control groups. The results from PCR indicated positive rates for these three groups 48%, 54%, and 49.3% using 5’-UTR primer and 15.1%, 12%, and 8% using N22 primer, respectively.Conclusion:Five genogroups were observed, which the second group was found to be the most frequent. The results of 5’-UTR primer showed more prevalence of TTV DNA comparing to N22 primer in patients and healthy control.

Genomoviruses associated with mountain and western pine beetles

Genomoviruses are circular single-stranded DNA viruses (∼2 kb in size) classified into nine genera, they are highly diverse and have been identified in a variety of samples ranging from fungi to animal sera. Here we identify five genomoviruses belonging to the Gemycircularvirus genus and one to the Gemykibivirus genus from mountain pine beetle and western pine beetle sampled in Arizona. Collectively these six viral genomes share <77% genome-wide pairwise identity and hence represent six new species of genomoviruses. Four of the gemycircularviruses from the mountain pine beetles are recombinant, with one having a recombinant region that spans the entire capsid protein. Pine beetles have a symbiotic relationship with certain tree pathogenic fungi. Therefore given that Sclerotinia sclerotiorum hypovirulence-associated DNA virus 1, a gemycircularvirus, induces hypovirulence in the plant pathogenic fungus Sclerotinia sclerotiorum and infects the mycophagous insect Lycoriella ingenua, it is possible that the six genomoviruses identified here may be directly associated with the pine beetle fungal symbionts and/or with the insects themselves.