Does it infect her; or does she infect it?
Posted on 12/08/2005 4:21:38 PM PST by neverdem
French biologists have just mapped out the genetic sequence of the largest known virus, and the complexity of the thing has them questioning what it is.
The genetic code of the mimivirus, as it is called, is three times longer than that of other viruses and contains elements that blur the lines between life and non-life.
Whether viruses are alive has been a matter of debate for more than half a century. They are often thought of as merely complex "biomolecules" – lifeless capsules of genetic information that must invade a living cell and hijack its machinery to reproduce.
The typical virus is 200 nanometers, or 8 millionths of an inch wide and writes its genetic code in either of two molecules: DNA or RNA, but not both.
Mimivirus, however, is more than 400 nanometers wide and has both DNA and RNA. It is so large and complex that researchers had trouble recognizing it as a virus.
"We considered it a bacteria for a year and a half," said Didier Raoult of the Universite de la Mediterranee in Marseilles, France.
Mimivirus was found during a search in 1992 for the source of an outbreak of pneumonia in Bradford, England. Although the virus was spotted inside an amoeba, it was not immediately identified and, therefore, sat in limbo for several years.
Raoult and his colleagues later obtained the mysterious "bug" and identified it as a virus a year ago. They named it mimivirus for the fact that it "mimics" bacteria. Mimivirus is, however, like other viruses in that it is not able to convert energy or replicate on its own.
The same group that identified the virus has now unraveled its genome. The work was described recently in the online version of the journal Science. Mimivirus was found to have 1.2 million base pairs – the ones and zeros of the genetic code. In this long data sequence, there are more than 1,200 genes, or "mini-programs" that give instructions for making proteins. Many bacteria do not have that many genes.
The biologists also discovered that mimivirus has seven genes common to all three of the generally-accepted domains of life: bacteria, archaea (like bacteria but slightly more complicated), and eukaryotes (everything else, from fungi to plants to animals).
There are 63 of these universal life genes. Prior to this, only one of these genes had been found in a virus.
Some of these common genes are involved in translation, which is the actual nuts and bolts of making a protein from the genetic blueprints.
"Viruses are parasites, so they can rely on the protein engineering of the host cell," Raoult said. He therefore found it "bizarre" that mimivirus would bother carrying around translation genes. The researchers are not yet sure, though, if the virus actually uses them.
Mimivirus’ unique nature may hold some key to the evolution of singe-celled organisms three billion years ago. Although it will likely take time to generate any consensus for it, the researchers advocate a fourth branch of life for mimivirus, and any other giant viruses that may turn up.
"It really is an organism," Raoult said. "You cannot believe it is just a biomolecule."
I've often thought that I am a lesbian trapped in a man's body.
Does it infect her; or does she infect it?
Thanks for the ping!
So you say.
The nano meter is 10^-9 while the Angstrom is 10^-10 so I think Fred's right.
you wrote "He's up for election next year... it'll be interesting to watch from afar."
Chirac? Up for election? Are you completely not paying attention. It is like someone in Europe thinking that Bush is up for election in 2008.
It is a battle between de Villepen and Sarkozy, but Chirac is gone next year.
Somewhere between a virus and a bacteria.
Reminds me of a witticism about Bavarians being the transition between Austrians and Human beings.
The typical virus is 200 nanometers, or 8 millionths of an inch wide and writes its genetic code in either of two molecules: DNA or RNA, but not both.
Mimivirus, however, is more than 400 nanometers wide and has both DNA and RNA. It is so large and complex that researchers had trouble recognizing it as a virus.
It took the French so long to figure it out because they are probably unfamiliar with the concept of the "double-wide," which any American scientist from tornado country can identify in an instant.
This is a very old story, as far as science goes, but this is a very interesting, er...., um.... thing, or "kind" .... or "biological entity".
It was a positively balmy -17 last night.
Heat wave, we're having a heat wave....
LOLOL!!!!
But, it's still a virus...
Escusez-moi. Je ne fais pas attention aux politiques du monde. Either candidate a good choice?
Only the French would name a new virus after their pet poodle.
"Either candidate a good choice?"
de Villepen is moreof the same. Sarkozy is really the best choice. By French standards he is quite conservative (actually they would say liberal, but we won't get into that).
With the exception of his support for the CAP - which if he was against it it would be the quivalent of being against baseball - his policies are to promote les reliance on the state and more on private enterprise. He is askingFrance to change and embrace globalization. He has a tough stand on crime/terrorism.
He is the one that said there is no "French model" because a model is something that benefits people and others want to emulate. With 10% unemployment, France does neither.
At the moment he is strongest candidate.
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