Now on ScienceBlogs: A study that oversells massage therapy

ScienceBlogs Book Club: Inside the Outbreaks

Mike the Mad Biologist

Mad rantings about politics, evolution, and microbiology

Search

Profile

ntm4-30-7 Mad rantings about politics, evolution, and microbiology. Comment policy: say what you want, but back it up with an email address. I don't like anonymous trolls.

Follow mikethemadbiol on Twitter

Recent Posts

Recent Comments

Archives

Blogroll

Science Links

« OK, Now I'm Convinced There Isn't an Anthrax Mixture | Main | Reporting on the Bush Disaster: Bestest Satire EVAH! »

Viruses That Parasitize Viruses?

Category: Viruses
Posted on: August 8, 2008 10:58 AM, by Mike

Welcome to the world of virophage--viruses that parasitize other viruses. What's interesting is that the 'host' viruses are the megaviruses which are visible with light microscopy and which have genomes that can be larger than some bacteria. From Science:

While examining a new giant amoeba virus in a cooling tower in Paris, the researchers found that the virus itself hosted tiny viral particles. They dubbed the virus's virus Sputnik and called it a "virophage" to parallel "bacteriophage," which is the name for a virus that infects bacteria. Unlike most viruses, Sputnik does not replicate by itself in amoeba and thus must hook up with the giant virus in order to persist. Infected giant viruses grow abnormally, with thicker capsules, and produce fewer progeny, La Scola and his colleagues report in the 7 August issue of Nature. They don't know if Sputnik is associated with other viruses.

Sputnik is puny: It has a circular chromosome that's just 18,000 bases long compared with the giant virus's 1.2-million-base linear chromosome. The chromosome is a mosaic of 21 protein-coding genes. Among them are three that appear to have been kidnapped from the giant virus, as well as a few that seem to have been transferred from viruses that infect bacteria or other microorganisms known as archaea.

And these virophages might be quite common:

Furthermore, 13 of its genes are completely new to researchers. And because some of Sputnik's genes have turned up in large-scale surveys of genetic material isolated from the ocean, La Scola expects that there are many more virophages waiting to be discovered.

The Nature article is available here (subscription needed).

Cited article: Bernard La Scola, Christelle Desnues, Isabelle Pagnier, Catherine Robert, Lina Barrassi, Ghislain Fournous, Michèle Merchat, Marie Suzan-Monti, Patrick Forterre, Eugene Koonin & Didier Raoult. 2008. The virophage as a unique parasite of the giant mimivirus. Nature doi:10.1038/nature07218.

Share on Facebook
Share on StumbleUpon
Share on Facebook
Find more posts in: Life Science

TrackBacks

TrackBack URL for this entry: http://scienceblogs.com/mt/pings/78369

Comments

1

You've a nicely done site with lots of effort and good updates. I would like to welcome you to submit your stories to www.surfurls.com and get that extra one way traffic to your site.

Posted by: surf | August 8, 2008 12:55 PM

2

"Great fleas have little fleas upon their backs to bite 'em,
And little fleas have lesser fleas, and so ad infinitum..."

Augustus De Morgan, A Budget of Paradoxes.


Posted by: NoAstronomer | August 8, 2008 3:47 PM

3

possible a case of The Selfish Gene?

Posted by: CheyneAllenLeVesseur | August 13, 2008 4:11 PM

4

@ NoAstronomer:

Yup. And the original but less well known version (1733) by Jonathan Swift:

So Nat'ralists observe, a Flea Hath smaller Fleas that on him prey, And these have smaller Fleas to bite 'em, And so proceed ad infinitum.

An idle thought - and probably a silly one, but I'm no biologist - occurred to me: Could something like this be made to eat HIV, bird flu, Ebola, SARS......

Posted by: themadlolscientist, FCD | August 13, 2008 7:27 PM

5

thanks

Posted by: mirc | March 13, 2009 5:25 PM

Post a Comment

(Email is required for authentication purposes only. On some blogs, comments are moderated for spam, so your comment may not appear immediately.)





ScienceBlogs

Search ScienceBlogs:

Go to:

Advertisement
Follow ScienceBlogs on Twitter

© 2006-2011 ScienceBlogs LLC. ScienceBlogs is a registered trademark of ScienceBlogs LLC. All rights reserved.