Coccolithovirus

Coccolithovirus
Virus classification
Group:	Group I (dsDNA)
Family:	Phycodnaviridae
Genus:	Coccolithovirus
Emiliania huxleyi virus 86 (EhV-86)

Coccolithovirus is a giant double-stranded DNA virus that infects Emiliania huxleyi, a species of coccolithophore^[1]. Its genome is 407,339 base pairs long with a G+C content of 41.1%, and contains 472 predicted coding sequences^[2].

Wilson and his team at the Marine Biological Association (MBA), University of East Anglia and Plymouth Marine Laboratory (PML), first observed the virus in 1999. Later in the summer of 2005 researchers at the Plymouth Marine Laboratory (Willie Wilson et al.) and at the Sanger Institute (Holden et al.) sequenced the genome for the EhV-86 strain finding it to have 472 protein-coding genes making it a "giant-virus", and the largest known marine virus by genome^[3].

From initial investigation of the Coccolithoviruses genome, a sequence of genes responsible for production of ceramide was discovered ^[4]. Ceramide is a controlling factor in cell death, and it is currently thought that Coccolithovirus uses this to prolong the life of Emiliania huxleyi while it uses the host cell to replicate. This is a unique ability unseen in any other viral genome to date.

Notes

1. ^ Giant viruses in the oceans: the 4th Algal Virus Workshop Virology Journal 2005
2. ^ Sanger institute home for Emiliania huxleyi virus 86
3. ^ Giantviruses.org top viruses by genome size.
4. ^ Plymouth Marine Laboratory press release.

See also

• Mimivirus - largest giant virus on record by genome
• Mycoplasma genitalium, Pelagibacter ubique - some of the smallest known bacteria
• Nanoarchaeum - smallest known archaeum
• Smallest organisms
• Parvovirus - smallest known family of viruses
• Phycodnaviridae - algae infecting viruses

Further reading

• Wilson, W. H., Schroeder, D. C., Allen, M. J., Holden, M. T. G., Parkhill, J., Barrell, B. G., Churcher, C., Hamlin, N., Mungall, K., Norbertczak, H., Quail, M. A., Price, C., Rabbinowitsch, E., Walker, D., Craigon, M., Roy, D. and Ghazal, P. (2005) Complete Genome Sequence and Lytic Phase Transcription Profile of a Coccolithovirus. Science 5737, 1090-1092
• Allen, M. J., Schroeder, D. C., Holden, M. T. and Wilson, W. H. (2006) Evolutionary History of the Coccolithoviridae. Mol Biol Evol. 23, 86-92 (Athens login required)

External links

• Viralzone: Coccolithovirus