''Amalgaviridae'' is a family of

double-stranded A base pair (bp) is a fundamental unit of double-stranded nucleic acids consisting of two nucleobases bound to each other by hydrogen bonds. They form the building blocks of the DNA double helix and contribute to the folded structure of both DN ...

RNA virus An RNA virus is a virusother than a retrovirusthat has ribonucleic acid (RNA) as its genetic material. The nucleic acid is usually single-stranded RNA ( ssRNA) but it may be double-stranded (dsRNA). Notable human diseases caused by RNA viruses ...

es. Member viruses infect

plant Plants are predominantly photosynthetic eukaryotes of the kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all current definitions of Plantae exclud ...

s and are transmitted vertically via

seed A seed is an embryonic plant enclosed in a protective outer covering, along with a food reserve. The formation of the seed is a part of the process of reproduction in seed plants, the spermatophytes, including the gymnosperm and angiospe ...

s. The name derives from ''amalgam'' (blend, mix) which refers to amalgaviruses possessing characteristics of both partitiviruses and totiviruses. There are ten species in the family.

Genome

Amalgavirus genomes are

monopartite Monopartite refers to the class of genome that is presented in the genome of the virus. As opposed to multipartite Multipartite is a class of virus that have segmented nucleic acid genomes, with each segment of the genome enclosed in a separate vi ...

and about 3.5

kilobase A base pair (bp) is a fundamental unit of double-stranded nucleic acids consisting of two nucleobases bound to each other by hydrogen bonds. They form the building blocks of the DNA double helix and contribute to the folded structure of both DNA ...

s in length. They have two partially overlapping

open reading frame In molecular biology, open reading frames (ORFs) 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 readin ...

s which encode the

RNA-dependent RNA polymerase RNA-dependent RNA polymerase (RdRp) or RNA replicase is an enzyme that catalyzes the replication of RNA from an RNA template. Specifically, it catalyzes synthesis of the RNA strand complementary to a given RNA template. This is in contrast to t ...

(RdRp) and a putative

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 may ...

protein.

Evolution

It has been suggested that amalgaviruses have evolved via recombination between viruses with double-stranded and negative-strand RNA genomes. Phylogenetic analysis indicates that the amalgavirus RdRp forms a sister clade to the corresponding RdRp protein of partitiviruses (''

Partitiviridae ''Partitiviridae'' is a family of double-stranded RNA viruses. Plants, fungi, and protozoa serve as natural hosts. It has been suggested that they can also infect bacteria. The name comes from the Latin ''partitius,'' which means divided, and ...

'') which have segmented (bipartite) dsRNA genomes and infect plants, fungi and protists. By contrast, the putative capsid protein of amalgaviruses is homologous to the nucleocapsid proteins of

negative-strand RNA virus Negative-strand RNA viruses (−ssRNA viruses) are a group of related viruses that have negative-sense, single-stranded genomes made of ribonucleic acid. They have genomes that act as complementary strands from which messenger RNA (mRNA) is sy ...

es of the genera ''

Phlebovirus ''Phlebovirus'' is one of twenty genera of the family ''Phenuiviridae'' in the order ''Bunyavirales''. The genus contains 66 species. It derives its name from Phlebotominae, the Vector (disease vector, vectors of member species ''Naples phlebovir ...

'' (''

Bunyaviridae ''Bunyavirales'' is an order of segmented negative-strand RNA viruses with mainly tripartite genomes. Member viruses infect arthropods, plants, protozoans, and vertebrates. It is the only order in the class ''Ellioviricetes''. The name ''Bunyavir ...

'') and ''

Tenuivirus ''Tenuivirus'' is a plant virus genus belonging to ''Phenuiviridae'' family in the order ''Bunyavirales''. These plant viruses cause diseases in their host plants. Typical symptoms are chlorotic stripes on the affected leaves. This group of virus ...

''.

Taxonomy

The family ''Amalgaviridae'' has two genera and ten species: '' Amalgavirus'' * ''

Allium cepa amalgavirus 1 ''Allium'' is a genus of monocotyledonous flowering plants that includes hundreds of species, including the cultivated onion, garlic, scallion, shallot, leek, and chives. The generic name ''Allium'' is the Latin word for garlic,Gledhill, David ...

'' * ''

Allium cepa amalgavirus 2 ''Allium'' is a genus of monocotyledonous flowering plants that includes hundreds of species, including the cultivated onion, garlic, scallion, shallot, leek, and chives. The Generic name (biology), generic name ''Allium'' is the Latin word for ...

'' * '' Blueberry latent virus'' * '' Rhododendron virus A'' * '' Southern tomato virus'' * '' Spinach amalgavirus 1'' * '' Vicia cryptic virus M'' * '' Zoostera marina amalgavirus 1'' * '' Zoostera marina amalgavirus 2'' '' Zybavirus'' * ' 'Zygosaccharomyces bailii virus Z''

References

{{Taxonbar, from=Q18810541 Double-stranded RNA viruses Riboviria Virus families