Figure 5 - available via license: Creative Commons Attribution 4.0 International
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Chaoborus RNA viruses infect the reproductive tissues. Small RNAs sequenced from the dissected ovaries of one adult and the unfertilized dissected eggs of another and mapped to virus contigs are enriched for 21 nt fragments characteristic of the siRNA pathway. Fragment size (nt) is plotted on the X-axis and raw numbers of reads are plotted on the Y-axis. The number of 21 nt reads is shown on the right side of each graph. Normalized 21 nt read abundance is shown above, in gray, as percent of 18-31 nt reads in each sample. Tolviot virus and Giez virus were each present in only one of the two individuals sequenced. Lantra virus RNA1 encodes the N, P, M, and G genes and RNA2 encodes the L gene. Ezimos virus RNA1 encodes the RdRp and RNA2 encodes the capsid protein. Alternating bar colors are applied as a visual aid to unite multisegmented viruses.
Source publication
Inherited mutualists, parasites, and commensals occupy one of the most intimate ecological niches available to invertebrate-associated microbes. How this transmission environment influences microbial evolution is increasingly understood for inherited bacterial symbionts, but in viruses, research on the prevalence of vertical transmission and its ef...
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Context 1
... tissues separately. Small RNA size profiles enriched in the 21 nt fragments produced by dipteran Dicer-2 were recovered for most of the novel viruses assembled from our larval stage RNAseq genomes. Within the libraries derived from reproductive tissues, siRNAs mapping to Tolviot, Lantra, Rovyktys, Niukluk, Giez, and Ezimos viruses are detected (Fig. 5), indicating infection by these viruses is maintained at least in part via inheritance. Tolviot virus and Giez virus were each present in only one of the two adults used to generate these libraries, and neither of the two adults were infected with Byreska, Byreldi, or Vaokses viruses. As a result, small RNA profiles for these viruses in ...
Context 2
... focused on mapping putative piRNAs from the ovaries sample, since we expect Piwi family endonucleases to be most active in germ line tissues. While small RNAs in the 24-31 nt size range could be mapped to each viral RNA (Supplementary Table S4), an unambiguous U1 bias was only observed for those that mapped to the Niukluk virus S segment ( Fig. 7B; nt frequency plots for all targets are shown in Supplementary Fig. S5). ...
Citations
... However, our sequencing datasets did not allow for the detection of small RNAs, the central molecules in the recognition of foreign nucleic acid. Evaluating the small RNA repertoire of BSF could provide more insight into the activation of antiviral pathways in this system [59]. Finally, we acknowledge that this method is exploratory, and factors other than the presence of viruses could influence the expression of these genes. ...
The mass rearing of animals in close quarters can be highly conducive to microbe transmission, including pathogens. This has been shown multiple times in the case of important industrial insects such as crickets, silkworms, and honeybees. One industrial insect of increasing importance is the black soldier fly (Diptera: Hermetia illucens), as it can convert organic waste into high-quality protein and fatty acids. Along with this, they take up far less space than traditional protein sources, as millions of black soldier flies can be reared in a relatively small facility. Because of this, there is a growing interest in the pathogens that could impact black soldier fly-rearing efforts. So far, only three black soldier fly-associated viruses have been identified. We used metatranscriptomic sequencing to survey black soldier fly guts, frass, and diet for viruses. We detected sequences from two novel viruses. One, which we name Hermetia illucens sigma-like virus 1, is phylogenetically related to viruses of the genus Sigmavirus, which have been highly studied in Drosophila. The other novel virus, which we name Hermetia illucens inse-like virus 1, is the second double-stranded RNA virus of the order Ghabrivirales described in the black soldier fly, and groups within a new family of insect viruses called the Inseviridae. We also detected two black soldier fly-associated viruses previously identified by our group: BSF nairo-like virus 1 and BSF uncharacterized bunyavirus-like 1. Consistent with our previous study, these two viruses are found primarily in frass samples and occur together more often than expected at random. When analyzing host transcription, we found significant differences in gene expression for eight candidate antiviral genes in the black soldier fly when comparing samples with and without viral sequences. Our results suggest that black soldier fly–virus interactions are ongoing, and they could be of interest to black soldier fly producers.
... All the virus sequences that we detected were distributed across geographically distant locations, so we investigated viral diversity between localities. We hypothesized that viral evolutionary relationships would reflect the differences in host species, and that within a host species, phylogenetic relationships would be reflective of geographic distance (Ballinger et al., 2022;Longdon et al., 2014). Specifically, we would expect C. lectularius and C. hemipterus to harbor closely related but distinct viral populations, and within C. lectularius, we would expect samples from Europe to be distinct from samples collected in North America. ...
Bed bugs
(Hemiptera: Cimicidae) are a globally distributed hematophagous pest that routinely feed on humans. Unlike many blood-sucking arthropods, they have never been linked to pathogen transmission in a natural setting, and despite increasing interest in their role as disease vectors, little is known about the viruses that bed bugs naturally harbor. Here, we present a global-scale survey of the bed bug RNA virosphere. We sequenced the metatranscriptomes of 22 individual bed bugs (Cimex lectularius and Cimex hemipterus) from 8 locations around the world. We detected sequences from two known bed bug viruses (Shuangao bedbug virus 1 and Shuangao bedbug virus 2) which extends their geographical range. We identified three novel bed bug virus sequences from a tenui-like virus (Bunyavirales), a toti-like virus (Ghabrivirales), and a luteo-like virus (Tolivirales). Interestingly, some of the bed bug viruses branch near to insect-transmitted plant-infecting viruses, opening questions regarding the evolution of plant virus infection. When we analyzed the viral sequences by their host's collection location, we found unexpected patterns of geographical diversity that may reflect humans’ role in bed bug dispersal. Additionally, we investigated the effect that Wolbachia, the primary bed bug endosymbiont, may have on viral abundance and found that Wolbachia infection neither promotes nor inhibits viral infection. Finally, our results provide no evidence that bed bugs transmit any known human pathogenic viruses.
... Viral infection is associated with transcriptional alterations of the host, including changes in the expression of genes that participate in important biological or pathological processes, such as antiviral responses, apoptosis, autophagy, inflammation, and necrosis (Rassmann et al., 2013). Viral infection is also known to alter the expression of noncoding RNAs, including microRNAs (miRNAs), small nuclear RNAs (snRNAs), long noncoding RNAs (lncRNAs), Piwi-interacting RNAs (piRNAs), and circular RNAs (circRNAs), which have been reported to facilitate viral replication or participate in apoptosis, proliferation, metabolism or antiviral immunity (Ballinger et al., 2022;Lai et al., 2021;Wang et al., 2022;Zhang et al., 2018). ...
Evidence is emerging on the roles of long noncoding RNAs (lncRNAs) as regulatory factors in a variety of viral infection processes, but the mechanisms underlying their functions in coxsackievirus group B type3 (CVB3)-induced acute viral myocarditis have not been explicitly delineated. We previously demonstrated that CVB3 infection decreases miRNA-21 expression; however, lncRNAs that regulate the miRNA-21-dependent CVB3 disease process have yet to be identified. To evaluate lncRNAs upstream of miRNA-21, differentially expressed lncRNAs in CVB3-infected mouse hearts were identified by microarray analysis and lncRNA/miRNA-21 interactions were predicted bioinformatically. MEG3 was identified as a candidate miRNA-21-interacting lncRNA upregulated in CVB3-infected mouse hearts. MEG3 expression was verified to be upregulated in HeLa cells 48 h post CVB3 infection and to act as a competitive endogenous RNA of miRNA-21. MEG3 knockdown resulted in the upregulation of miRNA-21, which inhibited CVB3 replication by attenuating P38-MAPK signaling in vitro and in vivo. Knockdown of MEG3 expression before CVB3 infection inhibited viral replication in mouse hearts and alleviated cardiac injury, which improved survival. Furthermore, the knockdown of CREB5, which was predicted bioinformatically to function upstream of MEG3, was demonstrated to decrease MEG3 expression and CVB3 viral replication. This study identifies the function of the lncRNA MEG3/miRNA-21/P38 MAPK axis in the process of CVB3 replication, for which CREB5 could serve as an upstream modulator.
Bed bugs (Hemiptera: Cimicidae ) are a globally distributed hematophagous pest that routinely feed on humans. Unlike many blood-sucking arthropods, they have never been linked to disease transmission in a natural setting, and despite interest in their role as disease vectors, little is known about the viruses that bed bugs naturally harbor. Here, we present a global-scale survey of the bed bug RNA virosphere. We sequenced the metatranscriptomes of 22 individual bed bugs ( Cimex lectularius and Cimex hemipterus ) from 8 locations around the world. We detected sequences from two known bed bug viruses (Shuangao bedbug virus 1 and Shuangao bedbug virus 2) which extends their geographical range and the host range of Shuangao bedbug virus 1 to Cimex lectularius . We identified three novel bed bug virus sequences from a tenui-like virus ( Bunyavirales ), a toti-like virus ( Ghabrivirales ), and a luteo-like virus ( Tolivirales ).
Interestingly, some of the bed bug viruses branch near to insect-transmitted plant-infecting viruses, opening questions regarding the evolution of plant virus infection. When we analyzed the putative viral sequences by their host’s collection location, we found unexpected patterns of geographical diversity that may reflect humans’ role in bed bug dispersal. Additionally, we investigated the effect that Wolbachia, the primary bed bug endosymbiont, may have on viral abundance and found that Wolbachia infection neither promotes nor inhibits viral infection. Finally, our results provide no evidence that bed bugs transmit any known human pathogenic viruses.
