Science Fair Project Encyclopedia
Ictalurivirus The Herpesviridae are a family of DNA viruses that cause diseases in humans and animals.
- HHV-1 = HSV-1 (herpes simplex virus 1): causes cold sores/genital herpes
- HHV-2 = HSV-2 (herpes simplex virus 2): causes cold sores/genital herpes
- HHV-3 = VZV (varicella-zoster virus): causes chickenpox and shingles
- HHV-4 = EBV (Epstein-Barr virus), lymphocryptovirus: causes infectious mononucleosis, Burkitt's lymphoma and nasopharyngeal carcinoma
- HHV-5 = CMV (cytomegalovirus): causes mononucleosis, retinitis , etc.
- HHV-6 = roseolovirus: causes "sixth disease" (roseola infantum, exanthem subitum)
- HHV-7 = closely related to HHV-6; causes roughly the same symptoms
- HHV-8 = rhadinovirus = KSHV = Kaposi's sarcoma herpesvirus
The human herpesviruses all share some common properties. One shared property is virus structure - all herpesviruses are composed of relatively large double stranded circular DNA genomes encoding 100-200 genes encased within an icosahedral protein cage called the capsid which is itself wrapped in a lipid bilayer membrane called the envelope. This particle is known as the virion. Following binding of viral envelope protein to cell membrane receptors, the virion is internalized and dismantled, allowing viral DNA to migrate to the cell nucleus. Within the nucleus, viral DNA undergoes limited replication and transcription of a small number of viral genes termed latent genes. In this fashion the virus can persist in the cell (and thus the host) indefinitely. While primary infection is often accompanied by a self-limited period of clinical illness, long-term latency is symptom-free. Following activation, the virus switches on transcription of multiple additional non-latent genes termed lytic genes that lead to enhanced replication and virus production. Often, lytic activation leads to cell death. Clinically, lytic activation is often accompanied by emergence of non-specific symptoms such as fever, headache, malaise, rash, etc.
The following genera are included here:
- Subfamily Alphaherpesvirinae
- Genus Simplexvirus ; type species: Human herpesvirus 1 or Herpes simplex; diseases: cold sores, genital herpes
- Genus Varicellovirus ; type species: Human herpesvirus 3 or Varicella-zoster virus; diseases: chickenpox, shingles
- Genus Mardivirus ; type species: Gallid herpesvirus 2
- Genus Iltovirus ; type species: Gallid herpesvirus 1
- Subfamily Betaherpesvirinae
- Subfamily Gammaherpesvirinae
- Genus Ictalurivirus ; type species: Ictalurid herpesvirus 1
The contents of this article is licensed from www.wikipedia.org under the GNU Free Documentation License. Click here to see the transparent copy and copyright details