Orthohepadnavirus


Orthohepadnavirus is a genus of viruses, in the family Hepadnaviridae. Humans and other mammals serve as natural hosts. There are 19 species in this genus. Diseases associated with this genus include: hepatitis, hepatocellular carcinoma, and cirrhosis.

Taxonomy

The genus contains the following species, listed by scientific name and followed by the exemplar virus of the species:Orthohepadnavirus bassarisci, Ringtail hepatitis B virusOrthohepadnavirus equidae, Equid hepatitis B virusOrthohepadnavirus felisdomestici, Domestic cat hepatitis B virusOrthohepadnavirus hominoidei, Hepatitis B virus genotype D - includes HBV and ape-infecting relatives. Named after the Hominoidea.Orthohepadnavirus lagothricis, Woolly monkey hepatitis B virusOrthohepadnavirus longidigiti, Long-fingered bat hepatitis B virusOrthohepadnavirus magniferrequini, Greater Horseshoe bat hepatitis B virusOrthohepadnavirus magnimyotis, Large myotis bat hepatitis B virusOrthohepadnavirus marmotae, Woodchuck hepatitis virusOrthohepadnavirus myominrhinus, Myodav bat hepatitis B virusOrthohepadnavirus philantombae, Tai Forest hepatitis B virusOrthohepadnavirus pomi, Pomona bat hepatitis B virusOrthohepadnavirus rotundifolii, Roundleaf bat hepatitis B virus - also includes HSBHBVOrthohepadnavirus sapaji, Capuchin monkey hepatitis B virusOrthohepadnavirus sciuri, Ground squirrel hepatitis virus Orthohepadnavirus soricicoronati, Crowned shrew hepatitis B virusOrthohepadnavirus soriciodoris, Musk shrew hepatitis B virusOrthohepadnavirus soricisinensis, Chinese shrew hepatitis B virusOrthohepadnavirus tabernarii, Tent-making bat hepatitis B virus
A few of the bat species were first reported in 2013.

Structure

Viruses in the genus Orthohepadnavirus are enveloped, with spherical geometries, and T=4 symmetry. The diameter is around 42 nm. Genomes are circular, around 3.2kb in length. The genome codes for 7 proteins.
GenusStructureSymmetryCapsidGenomic arrangementGenomic segmentation
OrthohepadnavirusIcosahedralT=4Non-envelopedCircularMonopartite

Life cycle

Viral replication is nucleo-cytoplasmic. Replication follows the dsDNA replication model. DNA-templated transcription, specifically dsDNA transcription, with some alternative splicing mechanism is the method of transcription. Translation takes place by leaky scanning. The virus exits the host cell by budding, and nuclear pore export. Human and mammals serve as the natural host. Transmission routes are sexual, blood, and contact.
GenusHost detailsTissue tropismEntry detailsRelease detailsReplication siteAssembly siteTransmission
OrthohepadnavirusHumans; mammalsHepatocytesCell receptor endocytosisBuddingNucleusCytoplasmVertical: parental; sex; blood