The Hepadnaviridae family includes enveloped viruses with a circular, partially double-stranded DNA as a genome. The virions of Hepadnaviridae are 42-50 nm in diameter in size and have an icosahedral capsid. The name of the family is composed of the two terms " hepar " (Latin liver) and "DNA" ( the genome). Thus it is indicated that the predominant Vermehrungsort for hepadnaviruses are liver cells. Viral species have so far been found only in mammals and birds.
Since they use during replication of the viral genome, a genomic RNA, which they describe transcriptase into DNA using a viral reverse, they are closely related to retroviruses and therefore the non- taxonomic group of Para retroviruses attributed. Very characteristic of the hepadnaviruses is the binding of a short piece of RNA, the initial piece of the primer reverse transcription of the DNA genome. Thus, they are the only viruses containing both viral DNA and viral RNA in the virion. Has a degree of similarity on the basis of sequence and testing of the arrangement of the family genes of a group of plant viruses, the Caulimoviridae.
The Hepadnaviridae family is currently divided into two genera. This is justified by comparing their genome sequence, but also reflects the presence in mammals ( "Real" hepadnaviruses: Orthohepadnavirus ) and birds ( Avihepadnavirus ) resist. Many other virus species discovered in primates and various birds are not yet definitively assigned to a genus or defined as a separate species.
- Family Hepadnaviridae
- Genus Orthohepadnavirus
- ( Known HBV in humans, 8 genotypes AH) species of hepatitis B virus
- Subtype orangutan hepadnavirus
- Subtype Woolly Monkey Hepatitis B virus ( WMHBV in woolly monkeys )
- Species Woodchuck hepatitis virus ( WHV, the woodchuck )
- Species Ground Squirrel Hepatitis Virus ( GHSV, the ground squirrel )
- Subtype Arctic Squirrel Hepatitis Virus ( ASHV, the Arctic ground squirrel )
- Genus Avihepadnavirus
- Species duck hepatitis B virus ( DHBV )
- Species heron hepatitis B virus ( HHBV, herons of the genus Ardea)
- Subtype stork hepatitis B virus ( STHBV )
- W.S. Mason, C. J. Burrell, J. Casey, W. H. Gerlich et al.: Family Hepadnaviridae. In: C. M. Fauquet, M. A. Mayo et al.: Eighth Report of the International Committee on Taxonomy of Viruses, London, San Diego, 2005, pp. 373-384