Jingmenvirus
   HOME

TheInfoList



OR:

Jingmenvirus is a group of
positive-sense single-stranded RNA virus Positive-strand RNA viruses (+ssRNA viruses) are a group of related viruses that have positive-sense, single-stranded genomes made of ribonucleic acid. The positive-sense genome can act as messenger RNA (mRNA) and can be directly translated i ...
es with segmented
genome A genome is all the genetic information of an organism. It consists of nucleotide sequences of DNA (or RNA in RNA viruses). The nuclear genome includes protein-coding genes and non-coding genes, other functional regions of the genome such as ...
s. They are primarily associated with
arthropod Arthropods ( ) are invertebrates in the phylum Arthropoda. They possess an arthropod exoskeleton, exoskeleton with a cuticle made of chitin, often Mineralization (biology), mineralised with calcium carbonate, a body with differentiated (Metam ...
s and are one of only two known segmented RNA viruses that infect animal hosts. The first group member, the Jingmen tick virus (JMTV), was described in 2014. Another member, the Guaico Culex virus (GCXV), has a highly unusual multicomponent architecture in which the genome segments are separately enclosed in different viral capsids.


Examples


Jingmen tick virus

The group's first member was described in 2014 and named the Jingmen tick virus (JMTV) because it was isolated from a
tick Ticks are parasitic arachnids of the order Ixodida. They are part of the mite superorder Parasitiformes. Adult ticks are approximately 3 to 5 mm in length depending on age, sex, and species, but can become larger when engorged. Ticks a ...
sampled in
Jingmen Jingmen ( zh, t=, s=, w=Ching1mên2, p=Jīngmén) is a prefecture-level city in central Hubei province, People's Republic of China. Jingmen is within an area where cotton and oil crops are planted. The population of the prefecture is 2,873,687 (2 ...
, China. It is an enveloped spherical virus slightly larger than its closest viral relatives. The JMTV genome has four segments, two containing genes with
sequence homology Sequence homology is the homology (biology), biological homology between DNA sequence, DNA, RNA sequence, RNA, or Protein primary structure, protein sequences, defined in terms of shared ancestry in the evolutionary history of life. Two segments ...
to non-structural proteins found in
flavivirus ''Flavivirus'', renamed ''Orthoflavivirus'' in 2023, is a genus of positive-strand RNA viruses in the family ''Flaviviridae''. The genus includes the West Nile virus, dengue virus, tick-borne encephalitis virus, yellow fever virus, Zika viru ...
es, including
methyltransferase Methyltransferases are a large group of enzymes that all methylate their substrates but can be split into several subclasses based on their structural features. The most common class of methyltransferases is class I, all of which contain a Ro ...
and
RNA-dependent RNA polymerase RNA-dependent RNA polymerase (RdRp) or RNA replicase is an enzyme that catalyzes the self-replication, replication of RNA from an RNA template. Specifically, it catalyzes synthesis of the RNA strand Complementarity (molecular biology), compleme ...
. The putative
structural protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respon ...
s in the JMTV genome have no known homologs. In addition to identification in ticks, JMTV has also been identified in low abundances in mosquitoes such as ''
Aedes albopictus ''Aedes albopictus'' (synonym (taxonomy), synonym ''Stegomyia albopicta''), from the mosquito (Culicidae) family (biology), family, also known as the (Asian) tiger mosquito or forest mosquito, is a mosquito native to the tropical and Subtropics ...
''.


Guaico Culex virus

The Guaico Culex virus (GCXV) was reported in 2016 after isolation from ''
Culex ''Culex'' or typical mosquitoes are a genus of mosquitoes, several species of which serve as vectors of one or more important diseases of birds, humans, and other animals. The diseases they vector include arbovirus infections such as West Nil ...
''
mosquito Mosquitoes, the Culicidae, are a Family (biology), family of small Diptera, flies consisting of 3,600 species. The word ''mosquito'' (formed by ''Musca (fly), mosca'' and diminutive ''-ito'') is Spanish and Portuguese for ''little fly''. Mos ...
es found near Guaico, Trinidad. Different virus isolates have four or five genome segments, though the fifth is not essential for viral proliferation. GCXV is a multicomponent (
multipartite Multipartite is a class of virus that have segmented nucleic acid genomes, with each segment of the genome enclosed in a separate viral particle. Only a few ssDNA viruses have multipartite genomes, but a many more RNA viruses have multipartite gen ...
) virus in which each genome segment is enclosed in its small, enveloped
viral capsid A capsid is the protein shell of a virus, enclosing its genetic material. It consists of several oligomeric (repeating) structural subunits made of protein called protomers. The observable 3-dimensional morphological subunits, which may or ma ...
. At least three genome segments, containing genes for non-structural proteins and capsid components, must enter a cell to infect it and reproduce the virus successfully. Before the discovery of GMXV, multicomponent architecture had previously been reported only in viruses that infect
plant Plants are the eukaryotes that form the Kingdom (biology), kingdom Plantae; they are predominantly Photosynthesis, photosynthetic. This means that they obtain their energy from sunlight, using chloroplasts derived from endosymbiosis with c ...
s and
fungi A fungus (: fungi , , , or ; or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and mold (fungus), molds, as well as the more familiar mushrooms. These organisms are classified as one ...
, and had never been observed in an enveloped virus.


Other viruses

Genetic material that likely belongs to other jingmenviruses can be identified through
bioinformatics Bioinformatics () is an interdisciplinary field of science that develops methods and Bioinformatics software, software tools for understanding biological data, especially when the data sets are large and complex. Bioinformatics uses biology, ...
. In some cases, such sequences were not recognized as viral or the segmented nature of the genome was not recognized before JMTV was described. For example, the reported genome of the dog parasite ''
Toxocara canis ''Toxocara canis'' (''T. canis'', also known as dog roundworm) is a worldwide-distributed helminth parasite that primarily infects dogs and other canids, but can also infect other animals including humans. The name is derived from the Greek wor ...
'' was found to contain sequences with homology to JMTV, likely representing a viral infection in the parasite that was sequenced. The Mogiana tick virus, first reported in 2011, is a similar example; its segmented genome was not recognized on first publication but was reanalyzed and identified as a jingmenvirus in 2017. Sequences with homology to JMTV have also been isolated from a
red colobus monkey Red colobuses are Old World monkeys of the genus ''Piliocolobus''. It was formerly considered a subgenus within the genus '' Procolobus'', which is now restricted to the olive colobus. They are closely related to the black-and-white colobus mon ...
, suggesting the possibility of a segmented, possibly multicomponent virus capable of infecting
primate Primates is an order (biology), order of mammals, which is further divided into the Strepsirrhini, strepsirrhines, which include lemurs, galagos, and Lorisidae, lorisids; and the Haplorhini, haplorhines, which include Tarsiiformes, tarsiers a ...
s. A
metagenomics Metagenomics is the study of all genetics, genetic material from all organisms in a particular environment, providing insights into their composition, diversity, and functional potential. Metagenomics has allowed researchers to profile the mic ...
study of arthropod flaviviruses identified five additional examples of likely jingmenvirus sequences.


Evolution

Jingmenviruses are related to
flavivirus ''Flavivirus'', renamed ''Orthoflavivirus'' in 2023, is a genus of positive-strand RNA viruses in the family ''Flaviviridae''. The genus includes the West Nile virus, dengue virus, tick-borne encephalitis virus, yellow fever virus, Zika viru ...
es, which have non-segmented genomes transmitted in a single capsid. Homology has consistently been observed between the genes encoding non-structural proteins of jingmenviruses and flaviviruses, including
RNA-dependent RNA polymerase RNA-dependent RNA polymerase (RdRp) or RNA replicase is an enzyme that catalyzes the self-replication, replication of RNA from an RNA template. Specifically, it catalyzes synthesis of the RNA strand Complementarity (molecular biology), compleme ...
. However, the genomic architecture of the homologous genes varies significantly; the canonical flavivirus genome consists of a single
open reading frame In molecular biology, reading frames are defined as spans of DNA sequence between the start and stop codons. Usually, this is considered within a studied region of a prokaryotic DNA sequence, where only one of the six possible reading frames ...
(ORF) whose protein product is processed by
protease A protease (also called a peptidase, proteinase, or proteolytic enzyme) is an enzyme that catalysis, catalyzes proteolysis, breaking down proteins into smaller polypeptides or single amino acids, and spurring the formation of new protein products ...
s, whereas the non-structural jingmenvirus proteins are encoded on two genome segments, each containing one ORF. Although there are few known jingmenvirus sequences, the gene composition of the genome segments appears to be well-conserved. By contrast, the putative jingmenvirus
structural protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respon ...
s that likely make up its
capsid A capsid is the protein shell of a virus, enclosing its genetic material. It consists of several oligomeric (repeating) structural subunits made of protein called protomers. The observable 3-dimensional morphological subunits, which may or m ...
s have no homology to known proteins. It is striking that the segmented jingmenviruses' closest known relatives are nonsegmented. The evolutionary mechanisms underlying genome segmentation and especially multicomponent architecture are poorly understood. Although segmented genomes appear to have evolved several times in the
virome Virome refers to the assemblage of viruses that is often investigated and described by metagenomic sequencing of viral nucleic acids that are found associated with a particular ecosystem, organism or holobiont. The word is frequently used to d ...
, the evolutionary mechanism underlying this structure is unclear. Likewise, It is unclear whether multicomponent architecture is a distinct evolutionary strategy or an artifact of the segmentation mechanism, possibly via the formation of
defective interfering particle Defective interfering particles (DIPs), also known as defective interfering viruses, are spontaneously generated virus mutants in which a critical portion of the particle's genome has been lost due to defective replication or non-homologous recomb ...
s.


References

{{Taxonbar, from=Q26700384 Positive-sense single-stranded RNA viruses