Viroids

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Viroids Lyndsay Murrow BMS 265
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Nomenclature
Viroid virus- like
Adapted from Flores R et al (1998) Arch Virol
143, 623-629.
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Discovery
1973 Electron micrograph shows viroids hairpin
structure
Early 1960s Raymer and OBrien develop a
bioassay for the agent causing potato spindle
tuber disease
1968 Characterization of chrysanthemum stunt and
citrus exocortis as non-typical viruses
1976 EM shows that viroids form closed circular
RNAs
1974 Confirmation that viroids are non-coding
1965 Raymer teams up with Diener they show that
agent is not a typical virion
1971 Diener demonstrates that the agent is a
free non-coding RNA, coins the term viroid
1978 PSTVd is sequenced
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Example Members
Genus Pospiviroids PSTVd (potato spindle
tuber) Genus Hostuviroids HSVd (hop
stunt) Genus Cocadviroids CCCVd (coconut
cadang-cadang) Genus Apscaviroids ASSVd
(apple scar skin)
Genus Coleviroids CbVd 1 (coleus blumei
1) Genus Avsunviroids ASBVd (avocado
sunblotch) Genus Pelamoviroids PLMVd (peach
latent mosaic)
Pospiviroidae Nuclear, CCR, no hammerhead
self-cleavage Avsunviroidae Chloroplastic, no
CCR, hammerhead self-cleavage
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Evolution and Conservation
Diener TO (1996) Virus Genes 11, 119-131.
William G. Scott
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Biogenesis
Adapted from Daròs J et al (2006) EMBO Reports 7,
593-598.
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Cellular Functions (Pathogenicity)
Pray LA (2004) The Scientist 18, 23.
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Mechanism of Action
Martick M and Scott WG (2006) SSRL Research
Highlight 11, 119-131. http//ssrl.slac.stanford.e
du/research/highlights_archive/ribozyme.html
http//rnaworld.bio.ku.edu
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Potential as a Tool
Citti L and Rainaldi G (2005) Curr Gene Ther 5,
11-24.