Viral Biorealm

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Viral Biorealm


Authors:


Molly Schlemmer '08, Shrochis Karki '09, Daniel Barich '05, Ryo Tashiro '09


Virus Classification: The Baltimore System


Group I. Double-stranded DNA viruses


Replicate using host or viral DNA polymerase.

Non-enveloped bacteriophages: Myoviridae.
Non-enveloped animal viruses: Adenoviridae, Papovaviridae, Phycodnaviridae, Iridoviridae.
Enveloped animal viruses: Herpesviridae, Poxviridae, Baculoviridae.

Group II. Single-stranded DNA


Genome consists of (+) sense DNA. Requires a host DNA polymerase to generate the complementary strand. Non-enveloped.

Non-enveloped bacteriophages: Inoviridae.
Archaeal virus: Fusellovirus.
Non-enveloped animal viruses: Parvoviridae, Circoviridae.
Non-enveloped plant viruses: Geminiviridae.

Group III. Double-stranded RNA


Requires viral RNA-dependent RNA polymerase; usually packages the polymerase before exiting host cell.

Non-segmented, enveloped, bacteriophage: Cystoviridae.
Segmented, non-enveloped, animal and plant hosts: Reoviridae, Birnaviridae, Varicosaviridae.

Group IV. (+) Sense single-stranded RNA viruses


Require viral RNA-dependent RNA polymerase to generate (-) template for progeny (+) genome. Usually non-segmented.

Non-enveloped bacteriophages: Leviviridae.
Non-enveloped animal and plant viruses: Bromoviridae, Picornaviridae, Tobamoviridae, Potyviridae.
Enveloped animal and plant viruses: Coronaviridae, Flaviviridae, Togaviridae.

Group V. (-) Sense single-stranded RNA viruses


Require viral RNA-dependent RNA transcriptase.

Segmented, enveloped: Orthomyxoviridae.
Nonsegmented, enveloped: Filoviridae, Rhabdoviridae, Paramyxoviridae.
Segmented (+/-) strand enveloped: Arenaviridae, Bunyaviridae.

Group VI. RNA Reverse Transcribing Viruses (Retroviruses)


Require viral reverse transcriptase to generate DNA copy for integration into host chromosome. Package transcriptase before exiting host cell.

Retroviridae

Group VII. DNA Reverse Transcribing Viruses (Pararetroviruses)


DNA is transcribed to RNA intermediate; reverse-transcribed to DNA. Infects plant cells, which have cytoplasmic reverse transcriptase; or package a viral reverse transcriptase.

Non-enveloped plant viruses: Caulimoviridae, Badnaviridae.
Enveloped animal viruses: Hepadnaviridae.