Evolution is a very complex phenomenon, affected by millions of variables and difficult to control precisely. At the purely mechanical level, however, we understand it quite well. The Rice research examined how viruses and bacteria mutate by exchanging genes and gene sets. Then they came up with a formula for several key factors: recombination rate, mutation rate and fitness function. If you know any two of the factors for a given organism, you can figure out the third. That means you can create a drug that will manipulate one of the factors and create a very specific outcome.

One such outcome is called lethal mutagenesis. Using a designer drug, you increase the mutation rate so fast that the population undergoes what bioengineers call a "phase change" (they liken their formula in many ways to thermodynamics, hence the reference to phases of matter). Rice professor Michael Deem described the ultimate result:

"If the mutation, recombination or horizontal gene transfer rates are too high, the system delocalizes and gets spread all over sequence space."

I have no idea what that means, but I'm sure it isn't good news for the virus. It also makes for great sci-fi dialogue.

Handsome Smuggler: Watch your horizontal transfer rate, kid. You don't want to delocalize the system.
Adventuresome Farm Boy: Why not?
Handsome Smuggler: Then we'll end up spread all over sequence space.
Adventuresome Farm Boy: I made out with my sister.

Image by: hans s.

Forced evolution: Can we mutate viruses to death? [EurekAlert!]

The BioBeer project will be entered into the International Genetically Engineered Machine (iGEM) competition to be held next month. Each team uses BioBricks, which are basically DNA toolkits, to create new lifeforms that do interesting things. Although the definition of "interesting" seems rather loose - past entrants included bacteria that smell different depending on whether they're growing or not.

The Rice team, several members of which are not old enough to drink, has genetically engineered a yeast so it will produce resveratrol in a two-step process (one gene produces some stuff, another gene makes the stuff into resveratrol). They haven't actually brewed any yet, and there are a whole lot of steps in between now and the day you can toss back a frosty mug of Cancer Destroyer Porter, but at least the team isn't creating something that could wipe out humanity. According the Rice press release:

Their entry last year, a bacterial virus that fought antibiotic resistance, was well-received but finished out of the prize running.

Now we just need some asthma-fighting pizza, or some anti-diabetes pretzels. Image by: a4gpa.

Better beer: college team creating anticancer brew. [Rice University via EurekAlerts!]