Duck hepatitis B virus, abbreviated DHBV, is part of the genus '' Avihepadnavirus'' of the ''

Hepadnaviridae ''Hepadnaviridae'' is a family of viruses. Humans, apes, and birds serve as natural hosts. The family contains five genera. Its best-known member is hepatitis B virus. Diseases associated with this family include: liver infections, such as hep ...

'', 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 A viral envelope is the outermost layer of many types of viruses. It protects the genetic material in their life cycle when traveling between host cells. Not all viruses have envelopes. A viral envelope protein or E protein is a protein in the en ...

is made up from host cell lipid, with viral surface antigens (DHBsAg). The icosahedral

nucleocapsid 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 ma ...

within, is composed of the virus core antigen (DHBcAg) and surrounds the DNA

genome A genome is all the genetic information of an organism. It consists of nucleotide sequences of DNA (or RNA in RNA viruses). The nuclear genome includes protein-coding genes and non-coding genes, other functional regions of the genome such as ...

and viral polymerase. The viral genome is a circular double stranded DNA molecule about 3000

base pair 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 long. The genome has three overlapping

open reading frame In molecular biology, reading frames 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 reading frames ...

s 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 Entry may refer to: *Entry, West Virginia, an unincorporated community in the United States *Entry (cards), a term used in trick-taking card-games *Entry (economics), a term in connection with markets *Entry (film), ''Entry'' (film), a 2013 Indian ...

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 Translation is the communication of the semantics, meaning of a #Source and target languages, source-language text by means of an Dynamic and formal equivalence, equivalent #Source and target languages, target-language text. The English la ...

and subsequent

protein synthesis Protein biosynthesis, or protein synthesis, is a core biological process, occurring inside cells, balancing the loss of cellular proteins (via degradation or export) through the production of new proteins. Proteins perform a number of critica ...

. 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 (HBV) is a partially double-stranded DNA virus, a species of the genus '' Orthohepadnavirus'' and a member of the '' Hepadnaviridae'' family of viruses. This virus causes the disease hepatitis B. Classification Hepatitis B ...

(HBV). The virus has also provided as a useful animal model in the absence of one from the HBV, and as scaffold for the development of chimeric virus-like particles.

References

{{DEFAULTSORT:Duck Hepatitis B Virus Hepadnaviridae Animal viral diseases Hepatitis B virus Poultry diseases