''Yaravirus'' is an amoebic

virus A virus is a submicroscopic infectious agent that replicates only inside the living Cell (biology), cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea. Viruses are ...

(a virus that reproduces in

amoeba An amoeba (; less commonly spelled ameba or amœba; : amoebas (less commonly, amebas) or amoebae (amebae) ), often called an amoeboid, is a type of Cell (biology), cell or unicellular organism with the ability to alter its shape, primarily by ...

) that is a sole representative of its own class, ''Mriyaviricetes'' (from mriya (мрія), a Ukrainian word for "dream" or "inspiration" + -viricetes). It was discovered in the waters of

Lake Pampulha __NOTOC__ Lake Pampulha ( Portuguese: Lagoa da Pampulha, ) is an artificial lake located in Pampulha, Belo Horizonte, in the Brazilian state of Minas Gerais. Pampulha is also the name of an administrative region (''região administrativa'') of ...

Minas Gerais Minas Gerais () is one of the 27 federative units of Brazil, being the fourth largest state by area and the second largest in number of inhabitants with a population of 20,539,989 according to the 2022 Brazilian census, 2022 census. Located in ...

Brazil Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of countries and dependencies by area, fifth-largest country by area and the List of countries and dependencies by population ...

, in 2020. The virus was found to be significantly smaller than any known amoebic virus, and is notable in that 90% of its genome appears to have no homology to previously sequenced

amino acid Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although over 500 amino acids exist in nature, by far the most important are the 22 α-amino acids incorporated into proteins. Only these 22 a ...

s in other organisms. The organism was named after the Brazilian mythological figure, Iara. One author described the virus as one that "simply makes no sense", and as "an extreme example", noting that "of ''Yaravirus 74 genes, 68 are unlike any ever found in any virus". With respect to efforts by scientists to develop a megataxonomy of viruses, ''Yaravirus'' was described as "lonely and unclassifiable". Another analysis describes the virus as "either highly reduced and divergent NCLDVs or, more probably, the first non-NCLDV isolated from ''

Acanthamoeba ''Acanthamoeba'' is a genus of amoeboid, amoebae that are commonly recovered from soil, fresh water, and other habitat (ecology), habitats. The genus ''Acanthamoeba'' has two stages in its life cycle, the metabolically active trophozoite stage a ...

'' species", also noting "an ATPase most similar to the

mimivirus ''Mimivirus'' is a genus of giant viruses, in the family ''Mimiviridae''. It is believed that Amoeba serve as their natural hosts. It also refers to a group of phylogenetically related large viruses. In colloquial speech, APMV is more commonly ...

homologue" and a major

capsid protein 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 ...

phylogeny that is "not compatible with that of the ATPase phylogeny", suggesting that the virus originated through a

horizontal gene transfer Horizontal gene transfer (HGT) or lateral gene transfer (LGT) is the movement of genetic material between organisms other than by the ("vertical") transmission of DNA from parent to offspring (reproduction). HGT is an important factor in the e ...

References

Further reading