Duck hepatitis B virus
Encyclopedia
Duck Hepatitis B virus, abbreviated DHBV, is part of the Avihepadnavirus
genus of the Hepadnaviridae
, and is the causal agent of duck hepatitis B.
DHBV is a small DNA virus
with a diameter of 40-45 nm. The viral envelope is made up from host cell lipid, with viral surface antigens (DHBsAg). The icosahedral nucleocapsid within, is composed of the virus core antigen (DHBcAg) and surrounds the DNA genome and viral polymerase. The viral genome is a circular double stranded DNA molecule about 3000 base pairs long. The genome has three overlapping open reading frames or ORFs:
On binding and entry
of the virus to the host cell, the genome is transported to the nucleus to be transcribed. Novel viral RNA is then transferred to the cytoplasm for translation and subsequent protein synthesis.
The Duck Hepatitis B virus has provided a basis for the use of vaccines and prophylactic treatments for individuals at high risk of human Hepatitis B virus
(HBV). The virus has also provided as a useful animal model in the absence of one from the HBV.
Avihepadnavirus
Avihepadnavirus, is the second genus of the Hepadnaviridae family, the first genus being the Orthohepadnaviruses. The Avihepadnaviruses consist of viruses which exclusively infect birds. The type species of this genus is the duck hepatitis B virus...
genus of the Hepadnaviridae
Hepadnaviridae
Hepadnaviruses are a family of viruses which can cause liver infections in humans and animals. There are two recognized genera:*Genus Orthohepadnavirus; type species: Hepatitis B virus...
, and is the causal agent of duck hepatitis B.
DHBV is a small DNA virus
DNA virus
A DNA virus is a virus that has DNA as its genetic material and replicates using a DNA-dependent DNA polymerase. The nucleic acid is usually double-stranded DNA but may also be single-stranded DNA . DNA viruses belong to either Group I or Group II of the Baltimore classification system for viruses...
with a diameter of 40-45 nm. The viral envelope is made up from host cell lipid, with viral surface antigens (DHBsAg). The icosahedral nucleocapsid within, is composed of the virus core antigen (DHBcAg) and surrounds the DNA genome and viral polymerase. The viral genome is a circular double stranded DNA molecule about 3000 base pairs long. The genome has three overlapping open reading frames or ORFs:
- C-ORF – encoding the core antigen and pre-core protein which are processed and secreted as DHBcAg
- S-ORF – codes for the surface antigen DHBsAg
- P-ORF – encoding the viral polymerase.
On binding and entry
Viral entry
Viral entry is the earliest stage of infection in the viral life cycle, as the virus comes into contact with the host cell and introduces viral material into the cell. The major steps involved in viral entry are shown below. Despite the variation among viruses, the generalities are quite similar...
of the virus to the host cell, the genome is transported to the nucleus to be transcribed. Novel viral RNA is then transferred to the cytoplasm for translation and subsequent protein synthesis.
The Duck Hepatitis B virus has provided a basis for the use of vaccines and prophylactic treatments for individuals at high risk of human Hepatitis B virus
Hepatitis B virus
Hepatitis B is an infectious illness caused by hepatitis B virus which infects the liver of hominoidea, including humans, and causes an inflammation called hepatitis. Originally known as "serum hepatitis", the disease has caused epidemics in parts of Asia and Africa, and it is endemic in China...
(HBV). The virus has also provided as a useful animal model in the absence of one from the HBV.