What disease does Hepadnaviridae cause?

Hepadnaviruses are a group of DNA viruses that infect hepatocytes and may cause liver injury and hepatocellular carcinoma (HCC) in mammals and birds. Hepatitis B virus (HBV) is the prototype of the family of hepadnaviruses that causes acute and chronic hepatitis B, cirrhosis, and HCC in human beings.

Does Hepadnaviridae have reverse transcriptase?

This enzyme is unique among viral polymerases in that it has reverse transcriptase activity to convert RNA into DNA to replicate the genome (the only other human-pathogenic virus family encoding a polymerase with this capability is Retroviridae), RNAse activity (used when the DNA genome is synthesized from pgRNA that …

Which organ is most affected by hepatitis B?

Hepatitis B (HBV) is a virus that attacks the liver. It causes the liver to become inflamed (swollen). Over time, the liver can become badly damaged.

What are 2 ways viruses can reproduce?

There are two processes used by viruses to replicate: the lytic cycle and lysogenic cycle. Some viruses reproduce using both methods, while others only use the lytic cycle. In the lytic cycle, the virus attaches to the host cell and injects its DNA.

Which among the following are the largest DNA viruses that infect humans?

Mimivirus, Mamavirus, and Marseillevirus all infect amoebae; the first two are the largest viruses ever reported (9). Mamavirus has an 18.3-kb DNA satellite virus (called Sputnik) that can only replicate in the presence of Mamavirus (34). Mimivirus virions have an icosahedral core capsid with a diameter of ~500 nm.

What are the members of the Hepadnaviridae family?

Hepadnaviridae is a family of viruses. Humans, apes, and birds serve as natural hosts. There are currently over species in this family, divided among 5 genera. Its best-known member is the Hepatitis B virus.

How does a Hepadnaviridae virus leave the cell?

These new virions either leave the cell to infect others or are immediately dismantled so the new viral genomes can enter the nucleus and magnify the infection. The virions that leave the cell egress through budding. Viruses in Hepadnaviridae are enveloped, with spherical geometries, and T=4 symmetry. The diameter is around 42 nm.

How big is the capsid of a hepadnavirus?

Hepadnaviruses have small, enveloped, spherical virions (virus particles) that are about 40–48 nm (1 nm = 10 −9 metre) in diameter. The capsid (the protein shell surrounding the viral nucleic acids) contains a circular double-stranded DNA molecule with a single-stranded DNA region and a DNA-dependent DNA polymerase.

How long does it take for hepadnavirus to show up in humans?

In humans the condition may occur as an acute disease, or in about 5 to 10 percent of cases it may become chronic and lead to permanent liver damage. Symptoms usually appear from 40 days to 6 months after exposure to the virus.