DNA viruses

DNA VIRUSES

Viruses with ds DNA genome

  • Family: Adenoviridae
    • Non enveloped, icosahedral with fibre protein at each vertex, ds stranded linear DNA, replication in nucleus
  • Family: Asfarviridae
    • Enveloped,200 nm icosahedral particle with 70 nm isometric core, linear ds DNA, cytoplasmic replication.
    • African swine fever virus
  • Family: Herpesviridae
    • Enveloped 200 nm particle with spikes,enclosing a tegument and an icosahedral nucleocapsid of 100 nm. Linear ds DNA, replication in nucleus. Large family, latency common, some are oncogenic.
    • Three subfamilies – alphaherpesvirinae, betaherpesvirinae and gammaherpesvirinae.
  • Family: Papilomaviridae
    • Non enveloped, 55 nm icosahedral, covalently closed circular ds DNA genome, replication in nucleus, some are oncogenic.
  • Family: Polyomaviridae
    • Nonenveloped, 40-45 nm icosahedral, covalently closed circular ds DNA , replication in nuceus oncogenic.
    • Simian virus 40 (SV 40)
  • Family: Poxviridae
    • Brick shaped or ovoid virions of 220-450 nm x 140-260 nm wide, some enveloped. Complex structure enclosing two lateral bodies and a biconcave core. Linear ds DNA genome, cytoplasmic replication.
    • Two subfamilies – Chordopoxvirinae (viruses of vertebrates) and Entomopoxvirinae (viruses of insects).

Viruses with ss DNA genomes

  • Family: Circoviridae
    • Nonenveloped small icosahedral, circular ss DNA genome
    • Porcine circovirus 1 and chicken anaemia virus
  • Family: Parvoviridae
    • Nonenveloped icosahedral 18-26 nm, linear ss DNA genome replication in nuceus.
    • Two sub families – Parvovirinae (viruses of vertebrates) and Densovirinae (viruses of mainly insects)

Viruses with DNA genome that replicate through RNA intermediate

  • Family: Hepadnaviride
    • 42-50 nm enveloped particle with projections, isometric nucleocapsid with DNA polymerase and protein kinase activities, partially ds DNA that is not covalently closed. Complete negative sense strand of 3000 nt and a variable length positive sense strand of 1700 – 2800 nt, contains reverse transcriptase.
    • Hepatitis B virus of humans, duck hepatitis B virus
Last modified: Friday, 23 September 2011, 11:04 AM