I performed metaviromic analysis of publicly available RNA-seq data from reptiles to understand the diversity of filoviruses (family Filoviridae). I identified a coding-complete sequence of a ...filovirus from the common lancehead (Bothrops atrox (Linnaeus, 1758)), tentatively named Tapajós virus (TAPV). Although the genome organization of TAPV is similar to mammalian filoviruses, our phylogenetic analysis showed that TAPV forms a cluster with a fish filovirus. However, TAPV is still distantly related to all the known filoviruses, suggesting that TAPV can be assigned as a species of a novel genus in Filoviridae. To our knowledge, this is the first report identifying a filovirus in reptiles, and thus contributes to a deeper understanding of the diversity and evolution of filoviruses.
•Various mammals harbor bornavirus-derived sequences in their genomes.•Some products from bornavirus-derived genes could suppress bornavirus replication.•A bornavirus-derived protein is involved in ...cellular functions in human cells.•Extensive surveys of bornaviruses are required for studies of bornavirus-derived genes.
The discoveries of sequences derived from non-retroviral viruses in eukaryotic genomes have significantly expanded our knowledge about virus evolution as well as the co-evolution between viruses and eukaryotes. However, the biological functions of such sequences in the host are largely unknown. Endogenous bornavirus-like elements (EBLs) have been relatively well studied by molecular biological methods, which have provided evidence that some EBLs have been co-opted by their hosts. This review highlights the current knowledge on the biological significance of EBLs, and discusses possible functions of EBLs. Further, we highlight the importance of extensive surveillance of exogenous viruses for a better understanding of endogenous viral sequences as well as the co-evolution of viruses and eukaryotes.
Riboviruses are viruses that have RNA genomes and replicate only via RNA intermediates. Although they do not require a DNA phase for replication and do not encode reverse transcriptase, the presence ...of DNA forms of riboviral sequences in ribovirus-infected cells has been reported since the 1970s. Additionally, heritable ribovirus-derived sequences, called riboviral endogenous viral elements (EVEs), have been found in the genomes of many eukaryotes. These are now thought to be formed by the reverse transcription machineries of retrotransposons within eukaryotic genomes sometimes referred to as selfish elements. Surprisingly, some reverse-transcribed riboviral DNAs (including EVEs) provide physiological functions for their hosts, suggesting the occurrence of novel interactions among eukaryotic genomes, retrotransposons and riboviruses, and opening the door to new avenues of investigation. Here I review current knowledge on these triangular interactions, and discuss future directions in this field.
Many mononegaviruses form inclusion bodies (IBs) in infected cells. However, little is known about nuclear IBs formed by mononegaviruses, since only a few lineages of animal-derived mononegaviruses ...replicate in the nucleus. In this study, we characterized the IBs formed by Nyamanini virus (NYMV), a unique tick-borne mononegavirus undergoing replication in the nucleus. We discovered that NYMV forms IBs, consisting of condensates and puncta of various sizes and morphologies, in the host nucleus. Likewise, we found that the expressions of NYMV nucleoprotein (N) and phosphoprotein (P) alone induce the formation of condensates and puncta in the nucleus, respectively, even though their morphologies are somewhat different from the IBs observed in the actual NYMV-infected cells. In addition, IB-like structures can be reconstructed by co-expressions of NYMV N and P, and localization analyses using a series of truncated mutants of P revealed that the C-terminal 27 amino acid residues of P are important for recruiting P to the condensates formed by N. Furthermore, we found that nuclear speckles, cellular biomolecular condensates, are reorganized and recruited to the IB-like structures formed by the co-expressions of N and P, as well as IBs formed in NYMV-infected cells. These features are unique among mononegaviruses, and our study has contributed to elucidating the replication mechanisms of nuclear-replicating mononegaviruses and the virus-host interactions.
Progress of information technology and SMEs Horie, Masayuki
Journal of Accounting Resarch for Small- and Medium-sized Entities,
2020, Letnik:
2020, Številka:
6
Journal Article
Although viruses have threatened our ancestors for millions of years, prehistoric epidemics of viruses are largely unknown. Endogenous bornavirus-like elements (EBLs) are ancient bornavirus sequences ...derived from the viral messenger RNAs that were reverse transcribed and inserted into animal genomes, most likely by retrotransposons. These elements can be used as molecular fossil records to trace past bornaviral infections. In this study, we systematically identified EBLs in vertebrate genomes and revealed the history of bornavirus infections over nearly 100 My. We confirmed that ancient bornaviral infections have occurred in diverse vertebrate lineages, especially in primate ancestors. Phylogenetic analyses indicated that primate ancestors were infected with various bornaviral lineages during evolution. EBLs in primate genomes formed clades according to their integration ages, suggesting that bornavirus lineages infected with primate ancestors had changed chronologically. However, some bornaviral lineages may have coexisted with primate ancestors and underwent repeated endogenizations for tens of millions of years. Moreover, a bornaviral lineage that coexisted with primate ancestors also endogenized in the genomes of some ancestral bats. The habitats of these bat ancestors have been reported to overlap with the migration route of primate ancestors. These results suggest that long-term virus-host coexistence expanded the geographic distributions of the bornaviral lineage along with primate migration and may have spread their infections to these bat ancestors. Our findings provide insight into the history of bornavirus infections over geological timescales that cannot be deduced from research using extant viruses alone, thus broadening our perspective on virus-host coevolution.
Zoonotic diseases considerably impact public health and socioeconomics. RNA viruses reportedly caused approximately 94% of zoonotic diseases documented from 1990 to 2010, emphasizing the importance ...of investigating RNA viruses in animals. Furthermore, it has been estimated that hundreds of thousands of animal viruses capable of infecting humans are yet to be discovered, warning against the inadequacy of our understanding of viral diversity. High‐throughput sequencing (HTS) has enabled the identification of viral infections with relatively little bias. Viral searches using both symptomatic and asymptomatic animal samples by HTS have revealed hidden viral infections. This review introduces the history of viral searches using HTS, current analytical limitations, and future potentials. We primarily summarize recent research on large‐scale investigations on viral infections reusing HTS data from public databases. Furthermore, considering the accumulation of uncultivated viruses, we discuss current studies and challenges for connecting viral sequences to their phenotypes using various approaches: performing data analysis, developing predictive modeling, or implementing high‐throughput platforms of virological experiments. We believe that this article provides a future direction in large‐scale investigations of potential zoonotic viruses using the HTS technology.
Members of the family
Bornaviridae
produce enveloped virions containing a linear negative-sense non-segmented RNA genome of about 9 kb. Bornaviruses are found in mammals, birds, reptiles and fish. ...The most-studied viruses with public health and veterinary impact are Borna disease virus 1 and variegated squirrel bornavirus 1, both of which cause fatal encephalitis in humans. Several orthobornaviruses cause neurological and intestinal disorders in birds, mostly parrots. Endogenous bornavirus-like sequences occur in the genomes of various animals. This is a summary of the International Committee on Taxonomy of Viruses (ICTV) Report on the family
Bornaviridae
, which is available at
ictv.global/report/bornaviridae
.
Progress of information technology and SMEs Horie, Masayuki
Journal of Accounting Resarch for Small- and Medium-sized Entities,
2019, Letnik:
2019, Številka:
5
Journal Article
Bornaviruses are the only animal RNA viruses that establish a persistent infection in their host cell nucleus. Studies of bornaviruses have provided unique information about viral replication ...strategies and virus–host interactions. Although bornaviruses do not integrate into the host genome during their replication cycle, we and others have recently reported that there are DNA sequences derived from the mRNAs of ancient bornaviruses in the genomes of vertebrates, including humans, and these have been designated endogenous borna-like (EBL) elements. Therefore, bornaviruses have been interacting with their hosts as driving forces in the evolution of host genomes in a previously unexpected way. Studies of EBL elements have provided new models for virology, evolutionary biology and general cell biology. In this review, we summarize the data on EBL elements including what we have newly identified in eukaryotes genomes, and discuss the biological significance of EBL elements, with a focus on EBL nucleoprotein elements in mammalian genomes. Surprisingly, EBL elements were detected in the genomes of invertebrates, suggesting that the host range of bornaviruses may be much wider than previously thought. We also review our new data on non-retroviral integration of Borna disease virus.
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